Java Android 的换行小部件布局

Question

提问by Henrik Gustafsson

I'm trying to create an activity that presents some data to the user. The data is such that it can be divided into 'words', each being a widget, and sequence of 'words' would form the data ('sentence'?), the ViewGroup widget containing the words. As space required for all 'words' in a 'sentence' would exceed the available horizontal space on the display, I would like to wrap these 'sentences' as you would a normal piece of text.

我正在尝试创建一个向用户呈现一些数据的活动。数据是这样的，它可以被分成“单词”，每个都是一个小部件，“单词”的序列将形成数据（“句子”？），包含单词的 ViewGroup 小部件。由于“句子”中所有“单词”所需的空间将超过显示器上可用的水平空间，因此我想像处理普通文本一样包装这些“句子”。

The following code:

以下代码：

public class WrapTest extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        LinearLayout l = new LinearLayout(this);
        LinearLayout.LayoutParams lp = new LinearLayout.LayoutParams(
                LinearLayout.LayoutParams.FILL_PARENT,
                LinearLayout.LayoutParams.WRAP_CONTENT);
        LinearLayout.LayoutParams mlp = new LinearLayout.LayoutParams(
                new ViewGroup.MarginLayoutParams(
                        LinearLayout.LayoutParams.WRAP_CONTENT,
                        LinearLayout.LayoutParams.WRAP_CONTENT));
        mlp.setMargins(0, 0, 2, 0);

        for (int i = 0; i < 10; i++) {
            TextView t = new TextView(this);
            t.setText("Hello");
            t.setBackgroundColor(Color.RED);
            t.setSingleLine(true);
            l.addView(t, mlp);
        }

        setContentView(l, lp);
    }
}

yields something like the left picture, but I would want a layout presenting the same widgets like in the right one.

产生类似于左图的东西，但我想要一个布局，呈现与右图相同的小部件。

non-wrapping

wrapping

Is there such a layout or combination of layouts and parameters, or do I have to implement my own ViewGroup for this?

是否有这样的布局或布局和参数的组合，或者我是否必须为此实现我自己的 ViewGroup？

Answer 1

采纳答案by Lukas Novak

Since May 2016 there is new layout called FlexboxLayout from Google, which is highly configurable for purpose you want.

自 2016 年 5 月以来，Google 推出了名为 FlexboxLayout 的新布局，它可以根据您的需要进行高度配置。

FlexboxLayout is in Google GitHub repository at https://github.com/google/flexbox-layoutat this moment.

FlexboxLayout 目前位于https://github.com/google/flexbox-layout 的Google GitHub 存储库中。

You can use it in your project by adding dependency to your build.gradlefile:

您可以通过向build.gradle文件添加依赖项在您的项目中使用它：

dependencies {
    compile 'com.google.android:flexbox:0.3.2'
}

More about FlexboxLayout usage and all the attributes you can find in repository readme or in Mark Allison articles here:

更多关于 FlexboxLayout 用法和所有属性，你可以在仓库自述文件或 Mark Allison 文章中找到：

https://blog.stylingandroid.com/flexboxlayout-part-1/

https://blog.stylingandroid.com/flexboxlayout-part2/

https://blog.stylingandroid.com/flexboxlayout-part-3/

Answer 2

回答by Will

Try setting both of lp's LayoutParams to be WRAP_CONTENT.

尝试将lp的 LayoutParams 都设置为WRAP_CONTENT。

Setting mlpto be WRAP_CONTENT, WRAP_CONTENTensures that your TextView(s) tare just wide and tall enough enough to hold "Hello" or whatever String you put in them. I think lmay not be aware of how wide your t's are. The setSingleLine(true)may be contributing too.

将mlp设置为WRAP_CONTENT，WRAP_CONTENT确保您的 TextView(s) t的宽度和高度足以容纳“Hello”或您放入其中的任何字符串。我想我可能不知道你的t有多宽。将setSingleLine(true)可能有助于太。

Answer 3

回答by Henrik Gustafsson

I made my own layout that does what I want, but it is quite limited at the moment. Comments and improvement suggestions are of course welcome.

我制作了自己想要的布局，但目前非常有限。当然欢迎提出意见和改进建议。

The activity:

活动：

package se.fnord.xmms2.predicate;

import se.fnord.android.layout.PredicateLayout;
import android.app.Activity;
import android.graphics.Color;
import android.os.Bundle;
import android.widget.TextView;

public class Predicate extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        PredicateLayout l = new PredicateLayout(this);
        for (int i = 0; i < 10; i++) {
            TextView t = new TextView(this);
            t.setText("Hello");
            t.setBackgroundColor(Color.RED);
            t.setSingleLine(true);
            l.addView(t, new PredicateLayout.LayoutParams(2, 0));
        }

        setContentView(l);
    }
}

Or in an XML layout:

或者在 XML 布局中：

<se.fnord.android.layout.PredicateLayout
    android:id="@+id/predicate_layout"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content"
/>

And the Layout:

和布局：

package se.fnord.android.layout;

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 * ViewGroup that arranges child views in a similar way to text, with them laid
 * out one line at a time and "wrapping" to the next line as needed.
 * 
 * Code licensed under CC-by-SA
 *  
 * @author Henrik Gustafsson
 * @see http://stackoverflow.com/questions/549451/line-breaking-widget-layout-for-android
 * @license http://creativecommons.org/licenses/by-sa/2.5/
 *
 */
public class PredicateLayout extends ViewGroup {

    private int line_height;

    public PredicateLayout(Context context) {
        super(context);
    }

    public PredicateLayout(Context context, AttributeSet attrs){
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        assert(MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

        final int width = MeasureSpec.getSize(widthMeasureSpec);

        // The next line is WRONG!!! Doesn't take into account requested MeasureSpec mode!
        int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
        final int count = getChildCount();
        int line_height = 0;

        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                child.measure(
                        MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
                        MeasureSpec.makeMeasureSpec(height, MeasureSpec.UNSPECIFIED));

                final int childw = child.getMeasuredWidth();
                line_height = Math.max(line_height, child.getMeasuredHeight() + lp.height);

                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }

                xpos += childw + lp.width;
            }
        }
        this.line_height = line_height;

        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED){
            height = ypos + line_height;

        } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST){
            if (ypos + line_height < height){
                height = ypos + line_height;
            }
        }
        setMeasuredDimension(width, height);
    }

    @Override
    protected LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(1, 1); // default of 1px spacing
    }

    @Override
    protected boolean checkLayoutParams(LayoutParams p) {
        return (p instanceof LayoutParams);
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = getChildCount();
        final int width = r - l;
        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childw = child.getMeasuredWidth();
                final int childh = child.getMeasuredHeight();
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }
                child.layout(xpos, ypos, xpos + childw, ypos + childh);
                xpos += childw + lp.width;
            }
        }
    }
}

With the result:

结果：

Wrapped widgets

Answer 4

回答by Mark

There is a problem with the first Answer:

第一个答案有问题：

child.measure(
    MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST),
    MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST));

In a ListView, for example, the list items are passed a heightMeasureSpec of 0 (UNSPECIFIED) and so, here, the MeasureSpec of size 0 (AT_MOST) is passed to all of the children. This means that the whole PredicateLayout is invisible (height 0).

例如，在 ListView 中，列表项的 heightMeasureSpec 被传递为 0 (UNSPECIFIED)，因此，这里，大小为 0 (AT_MOST) 的 MeasureSpec 被传递给所有子项。这意味着整个 PredicateLayout 是不可见的（高度为 0）。

As a quick fix, I changed the child height MeasureSpec like this:

作为快速修复，我像这样更改了孩子的身高 MeasureSpec：

int childHeightMeasureSpec;
if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
    childHeightMeasureSpec =
        MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
}
else {
    childHeightMeasureSpec = 
        MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);            
}

and then

进而

child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), 
    childHeightMeasureSpec);

which seems to work for me although does not handle EXACT mode which would be much more tricky.

这似乎对我有用，但不处理 EXACT 模式，这会更加棘手。

Answer 5

回答by Micah Hainline

I implemented something very similar to this, but using what I think is a little more standard way to handle spacing and padding. Please let me know what you guys think, and feel free to reuse without attribution:

我实现了与此非常相似的东西，但使用我认为更标准的方法来处理间距和填充。请让我知道你们的想法，并随意重复使用，无需署名：

package com.asolutions.widget;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import com.asolutions.widget.R;

public class RowLayout extends ViewGroup {
    public static final int DEFAULT_HORIZONTAL_SPACING = 5;
    public static final int DEFAULT_VERTICAL_SPACING = 5;
    private final int horizontalSpacing;
    private final int verticalSpacing;
    private List<RowMeasurement> currentRows = Collections.emptyList();

    public RowLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
        TypedArray styledAttributes = context.obtainStyledAttributes(attrs, R.styleable.RowLayout);
        horizontalSpacing = styledAttributes.getDimensionPixelSize(R.styleable.RowLayout_android_horizontalSpacing,
                DEFAULT_HORIZONTAL_SPACING);
        verticalSpacing = styledAttributes.getDimensionPixelSize(R.styleable.RowLayout_android_verticalSpacing,
                DEFAULT_VERTICAL_SPACING);
        styledAttributes.recycle();
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
        final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
        final int maxInternalWidth = MeasureSpec.getSize(widthMeasureSpec) - getHorizontalPadding();
        final int maxInternalHeight = MeasureSpec.getSize(heightMeasureSpec) - getVerticalPadding();
        List<RowMeasurement> rows = new ArrayList<RowMeasurement>();
        RowMeasurement currentRow = new RowMeasurement(maxInternalWidth, widthMode);
        rows.add(currentRow);
        for (View child : getLayoutChildren()) {
            LayoutParams childLayoutParams = child.getLayoutParams();
            int childWidthSpec = createChildMeasureSpec(childLayoutParams.width, maxInternalWidth, widthMode);
            int childHeightSpec = createChildMeasureSpec(childLayoutParams.height, maxInternalHeight, heightMode);
            child.measure(childWidthSpec, childHeightSpec);
            int childWidth = child.getMeasuredWidth();
            int childHeight = child.getMeasuredHeight();
            if (currentRow.wouldExceedMax(childWidth)) {
                currentRow = new RowMeasurement(maxInternalWidth, widthMode);
                rows.add(currentRow);
            }
            currentRow.addChildDimensions(childWidth, childHeight);
        }

        int longestRowWidth = 0;
        int totalRowHeight = 0;
        for (int index = 0; index < rows.size(); index++) {
            RowMeasurement row = rows.get(index);
            totalRowHeight += row.getHeight();
            if (index < rows.size() - 1) {
                totalRowHeight += verticalSpacing;
            }
            longestRowWidth = Math.max(longestRowWidth, row.getWidth());
        }
        setMeasuredDimension(widthMode == MeasureSpec.EXACTLY ? MeasureSpec.getSize(widthMeasureSpec) : longestRowWidth
                + getHorizontalPadding(), heightMode == MeasureSpec.EXACTLY ? MeasureSpec.getSize(heightMeasureSpec)
                : totalRowHeight + getVerticalPadding());
        currentRows = Collections.unmodifiableList(rows);
    }

    private int createChildMeasureSpec(int childLayoutParam, int max, int parentMode) {
        int spec;
        if (childLayoutParam == LayoutParams.FILL_PARENT) {
            spec = MeasureSpec.makeMeasureSpec(max, MeasureSpec.EXACTLY);
        } else if (childLayoutParam == LayoutParams.WRAP_CONTENT) {
            spec = MeasureSpec.makeMeasureSpec(max, parentMode == MeasureSpec.UNSPECIFIED ? MeasureSpec.UNSPECIFIED
                    : MeasureSpec.AT_MOST);
        } else {
            spec = MeasureSpec.makeMeasureSpec(childLayoutParam, MeasureSpec.EXACTLY);
        }
        return spec;
    }

    @Override
    protected void onLayout(boolean changed, int leftPosition, int topPosition, int rightPosition, int bottomPosition) {
        final int widthOffset = getMeasuredWidth() - getPaddingRight();
        int x = getPaddingLeft();
        int y = getPaddingTop();

        Iterator<RowMeasurement> rowIterator = currentRows.iterator();
        RowMeasurement currentRow = rowIterator.next();
        for (View child : getLayoutChildren()) {
            final int childWidth = child.getMeasuredWidth();
            final int childHeight = child.getMeasuredHeight();
            if (x + childWidth > widthOffset) {
                x = getPaddingLeft();
                y += currentRow.height + verticalSpacing;
                if (rowIterator.hasNext()) {
                    currentRow = rowIterator.next();
                }
            }
            child.layout(x, y, x + childWidth, y + childHeight);
            x += childWidth + horizontalSpacing;
        }
    }

    private List<View> getLayoutChildren() {
        List<View> children = new ArrayList<View>();
        for (int index = 0; index < getChildCount(); index++) {
            View child = getChildAt(index);
            if (child.getVisibility() != View.GONE) {
                children.add(child);
            }
        }
        return children;
    }

    protected int getVerticalPadding() {
        return getPaddingTop() + getPaddingBottom();
    }

    protected int getHorizontalPadding() {
        return getPaddingLeft() + getPaddingRight();
    }

    private final class RowMeasurement {
        private final int maxWidth;
        private final int widthMode;
        private int width;
        private int height;

        public RowMeasurement(int maxWidth, int widthMode) {
            this.maxWidth = maxWidth;
            this.widthMode = widthMode;
        }

        public int getHeight() {
            return height;
        }

        public int getWidth() {
            return width;
        }

        public boolean wouldExceedMax(int childWidth) {
            return widthMode == MeasureSpec.UNSPECIFIED ? false : getNewWidth(childWidth) > maxWidth;
        }

        public void addChildDimensions(int childWidth, int childHeight) {
            width = getNewWidth(childWidth);
            height = Math.max(height, childHeight);
        }

        private int getNewWidth(int childWidth) {
            return width == 0 ? childWidth : width + horizontalSpacing + childWidth;
        }
    }
}

This also requires an entry under /res/values/attrs.xml, which you can create if it's not already there.

这还需要 /res/values/attrs.xml 下的条目，如果该条目尚未存在，您可以创建该条目。

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="RowLayout">
        <attr name="android:verticalSpacing" />
        <attr name="android:horizontalSpacing" />
    </declare-styleable>
</resources>

Usage in an xml layout looks like this:

在 xml 布局中的用法如下所示：

<?xml version="1.0" encoding="utf-8"?>
<com.asolutions.widget.RowLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:padding="10dp"
    android:horizontalSpacing="10dp"
    android:verticalSpacing="20dp">
    <FrameLayout android:layout_width="30px" android:layout_height="40px" android:background="#F00"/>
    <FrameLayout android:layout_width="60px" android:layout_height="40px" android:background="#F00"/>
    <FrameLayout android:layout_width="70px" android:layout_height="20px" android:background="#F00"/>
    <FrameLayout android:layout_width="20px" android:layout_height="60px" android:background="#F00"/>
    <FrameLayout android:layout_width="10px" android:layout_height="40px" android:background="#F00"/>
    <FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
    <FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
    <FrameLayout android:layout_width="40px" android:layout_height="40px" android:background="#F00"/>
</com.asolutions.widget.RowLayout>

Answer 6

回答by Melinda Green

Here is my simplified, code-only version:

这是我的简化的纯代码版本：

    package com.superliminal.android.util;

    import android.content.Context;
    import android.util.AttributeSet;
    import android.view.View;
    import android.view.ViewGroup;


    /**
     * A view container with layout behavior like that of the Swing FlowLayout.
     * Originally from http://nishantvnair.wordpress.com/2010/09/28/flowlayout-in-android/ itself derived from
     * http://stackoverflow.com/questions/549451/line-breaking-widget-layout-for-android
     *
     * @author Melinda Green
     */
    public class FlowLayout extends ViewGroup {
        private final static int PAD_H = 2, PAD_V = 2; // Space between child views.
        private int mHeight;

        public FlowLayout(Context context) {
            super(context);
        }

        public FlowLayout(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);
            final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
            int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
            final int count = getChildCount();
            int xpos = getPaddingLeft();
            int ypos = getPaddingTop();
            int childHeightMeasureSpec;
            if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST)
                childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
            else
                childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
            mHeight = 0;
            for(int i = 0; i < count; i++) {
                final View child = getChildAt(i);
                if(child.getVisibility() != GONE) {
                    child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
                    final int childw = child.getMeasuredWidth();
                    mHeight = Math.max(mHeight, child.getMeasuredHeight() + PAD_V);
                    if(xpos + childw > width) {
                        xpos = getPaddingLeft();
                        ypos += mHeight;
                    }
                    xpos += childw + PAD_H;
                }
            }
            if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
                height = ypos + mHeight;
            } else if(MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
                if(ypos + mHeight < height) {
                    height = ypos + mHeight;
                }
            }
            height += 5; // Fudge to avoid clipping bottom of last row.
            setMeasuredDimension(width, height);
        } // end onMeasure()

        @Override
        protected void onLayout(boolean changed, int l, int t, int r, int b) {
            final int width = r - l;
            int xpos = getPaddingLeft();
            int ypos = getPaddingTop();
            for(int i = 0; i < getChildCount(); i++) {
                final View child = getChildAt(i);
                if(child.getVisibility() != GONE) {
                    final int childw = child.getMeasuredWidth();
                    final int childh = child.getMeasuredHeight();
                    if(xpos + childw > width) {
                        xpos = getPaddingLeft();
                        ypos += mHeight;
                    }
                    child.layout(xpos, ypos, xpos + childw, ypos + childh);
                    xpos += childw + PAD_H;
                }
            }
        } // end onLayout()

    }

Answer 7

回答by Aurélien Guillard

I have updated this sample to fix a bug, now, each line can have a different height !

我已更新此示例以修复错误，现在，每行都可以有不同的高度！

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

/**
 * ViewGroup that arranges child views in a similar way to text, with them laid
 * out one line at a time and "wrapping" to the next line as needed.
 * 
 * Code licensed under CC-by-SA
 *  
 * @author Henrik Gustafsson
 * @see http://stackoverflow.com/questions/549451/line-breaking-widget-layout-for-android
 * @license http://creativecommons.org/licenses/by-sa/2.5/
 *
 * Updated by Aurélien Guillard
 * Each line can have a different height
 * 
 */
public class FlowLayout extends ViewGroup {

    public static class LayoutParams extends ViewGroup.LayoutParams {

        public final int horizontal_spacing;
        public final int vertical_spacing;

        /**
         * @param horizontal_spacing Pixels between items, horizontally
         * @param vertical_spacing Pixels between items, vertically
         */
        public LayoutParams(int horizontal_spacing, int vertical_spacing) {
            super(0, 0);
            this.horizontal_spacing = horizontal_spacing;
            this.vertical_spacing = vertical_spacing;
        }
    }

    public FlowLayout(Context context) {
        super(context);
    }

    public FlowLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

        final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();

        int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
        final int count = getChildCount();
        int line_height = 0;

        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();

        int childHeightMeasureSpec;

        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);

        } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY) {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);

        } else {
            childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
        }

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();
                child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
                final int childw = child.getMeasuredWidth();

                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += line_height;
                }

                xpos += childw + lp.horizontal_spacing;
                line_height = child.getMeasuredHeight() + lp.vertical_spacing;
            }
        }

        if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
            height = ypos + line_height;

        } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
            if (ypos + line_height < height) {
                height = ypos + line_height;
            }
        }
        setMeasuredDimension(width, height);
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new LayoutParams(1, 1); // default of 1px spacing
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        if (p instanceof LayoutParams) {
            return true;
        }
        return false;
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        final int count = getChildCount();
        final int width = r - l;
        int xpos = getPaddingLeft();
        int ypos = getPaddingTop();
        int lineHeight = 0;

        for (int i = 0; i < count; i++) {
            final View child = getChildAt(i);
            if (child.getVisibility() != GONE) {
                final int childw = child.getMeasuredWidth();
                final int childh = child.getMeasuredHeight();
                final LayoutParams lp = (LayoutParams) child.getLayoutParams();

                if (xpos + childw > width) {
                    xpos = getPaddingLeft();
                    ypos += lineHeight;
                }

                lineHeight = child.getMeasuredHeight() + lp.vertical_spacing;

                child.layout(xpos, ypos, xpos + childw, ypos + childh);
                xpos += childw + lp.horizontal_spacing;
            }
        }
    }
}

Answer 8

回答by Henry

Some of the different answers here would give me a ClassCastExceptionin the Exclipse layout editor. In my case, I wanted to use ViewGroup.MarginLayoutParams rather than making my own. Either way, make sure to return the instance of LayoutParams that your custom layout class needs in generateLayoutParams. This is what mine looks like, just replace MarginLayoutParams with the one your ViewGroup needs:

这里的一些不同答案会在 Exclipse 布局编辑器中给我一个ClassCastException。就我而言，我想使用 ViewGroup.MarginLayoutParams 而不是自己制作。无论哪种方式，请确保在 generateLayoutParams 中返回自定义布局类所需的 LayoutParams 实例。这就是我的样子，只需将 MarginLayoutParams 替换为您的 ViewGroup 需要的：

@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
    return new MarginLayoutParams(getContext(), attrs);
}

@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    return p instanceof MarginLayoutParams;
}

It looks like this method gets called to to assign a LayoutParams object for each child in the ViewGroup.

看起来这个方法被调用来为 ViewGroup 中的每个孩子分配一个 LayoutParams 对象。

Answer 9

回答by Mohsen Afshin

The android-flowlayoutproject by ApmeM support line breaks, too.

ApmeM的android-flowlayout 项目也支持换行。

enter image description here

Answer 10

回答by Muhammad Aamir Ali

    LinearLayout row = new LinearLayout(this);

    //get the size of the screen
    Display display = getWindowManager().getDefaultDisplay();
    this.screenWidth = display.getWidth();  // deprecated

    for(int i=0; i<this.users.length; i++) {

        row.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));

        this.tag_button = new Button(this);
        this.tag_button.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, 70));
        //get the size of the button text
        Paint mPaint = new Paint();
        mPaint.setAntiAlias(true);
        mPaint.setTextSize(tag_button.getTextSize());
        mPaint.setTypeface(Typeface.create(Typeface.SERIF, Typeface.NORMAL));
        float size = mPaint.measureText(tag_button.getText().toString(), 0, tag_button.getText().toString().length());
        size = size+28;
        this.totalTextWidth += size;

        if(totalTextWidth < screenWidth) {
            row.addView(tag_button);
        } else {
            this.tags.addView(row);
            row = new LinearLayout(this);
            row.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
            row.addView(tag_button);
            this.totalTextWidth = size;
        }
    }

Answer 11

回答by Ernestas Vaiciukevi?ius

My slightly modified version based on posted here previously:

我根据之前在这里发布的稍微修改过的版本：

It works in Eclipse layout editor

It centers all the items horizontally

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

public class FlowLayout extends ViewGroup {

private int line_height;

public static class LayoutParams extends ViewGroup.LayoutParams {

    public final int horizontal_spacing;
    public final int vertical_spacing;

    /**
     * @param horizontal_spacing Pixels between items, horizontally
     * @param vertical_spacing Pixels between items, vertically
     */
    public LayoutParams(int horizontal_spacing, int vertical_spacing, ViewGroup.LayoutParams viewGroupLayout) {
        super(viewGroupLayout);
        this.horizontal_spacing = horizontal_spacing;
        this.vertical_spacing = vertical_spacing;
    }

    /**
     * @param horizontal_spacing Pixels between items, horizontally
     * @param vertical_spacing Pixels between items, vertically
     */
    public LayoutParams(int horizontal_spacing, int vertical_spacing) {
        super(0, 0);
        this.horizontal_spacing = horizontal_spacing;
        this.vertical_spacing = vertical_spacing;
    }
}

public FlowLayout(Context context) {
    super(context);
}

public FlowLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

    final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
    int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
    final int count = getChildCount();
    int line_height = 0;

    int xpos = getPaddingLeft();
    int ypos = getPaddingTop();

    int childHeightMeasureSpec;
    if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
    } else {
        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
    }


    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
            final int childw = child.getMeasuredWidth();
            line_height = Math.max(line_height, child.getMeasuredHeight() + lp.vertical_spacing);

            if (xpos + childw > width) {
                xpos = getPaddingLeft();
                ypos += line_height;
            }

            xpos += childw + lp.horizontal_spacing;
        }
    }
    this.line_height = line_height;

    if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
        height = ypos + line_height;

    } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
        if (ypos + line_height < height) {
            height = ypos + line_height;
        }
    }
    setMeasuredDimension(width, height);
}

@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(1, 1); // default of 1px spacing
}

@Override
protected android.view.ViewGroup.LayoutParams generateLayoutParams(
        android.view.ViewGroup.LayoutParams p) {
    return new LayoutParams(1, 1, p);
}

@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    if (p instanceof LayoutParams) {
        return true;
    }
    return false;
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
    final int width = r - l;
    int xpos = getPaddingLeft();
    int ypos = getPaddingTop();

    int lastHorizontalSpacing = 0;
    int rowStartIdx = 0;

    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            final int childw = child.getMeasuredWidth();
            final int childh = child.getMeasuredHeight();
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            if (xpos + childw > width) {
                final int freeSpace = width - xpos + lastHorizontalSpacing;
                xpos = getPaddingLeft() + freeSpace / 2;

                for (int j = rowStartIdx; j < i; ++j) {
                    final View drawChild = getChildAt(j);
                    drawChild.layout(xpos, ypos, xpos + drawChild.getMeasuredWidth(), ypos + drawChild.getMeasuredHeight());
                    xpos += drawChild.getMeasuredWidth() + ((LayoutParams)drawChild.getLayoutParams()).horizontal_spacing;
                }

                lastHorizontalSpacing = 0;
                xpos = getPaddingLeft();
                ypos += line_height;
                rowStartIdx = i;
            } 

            child.layout(xpos, ypos, xpos + childw, ypos + childh);
            xpos += childw + lp.horizontal_spacing;
            lastHorizontalSpacing = lp.horizontal_spacing;
        }
    }

    if (rowStartIdx < count) {
        final int freeSpace = width - xpos + lastHorizontalSpacing;
        xpos = getPaddingLeft() + freeSpace / 2;

        for (int j = rowStartIdx; j < count; ++j) {
            final View drawChild = getChildAt(j);
            drawChild.layout(xpos, ypos, xpos + drawChild.getMeasuredWidth(), ypos + drawChild.getMeasuredHeight());
            xpos += drawChild.getMeasuredWidth() + ((LayoutParams)drawChild.getLayoutParams()).horizontal_spacing;
        }
    }
}
}

它适用于 Eclipse 布局编辑器

它将所有项目水平居中

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

public class FlowLayout extends ViewGroup {

private int line_height;

public static class LayoutParams extends ViewGroup.LayoutParams {

    public final int horizontal_spacing;
    public final int vertical_spacing;

    /**
     * @param horizontal_spacing Pixels between items, horizontally
     * @param vertical_spacing Pixels between items, vertically
     */
    public LayoutParams(int horizontal_spacing, int vertical_spacing, ViewGroup.LayoutParams viewGroupLayout) {
        super(viewGroupLayout);
        this.horizontal_spacing = horizontal_spacing;
        this.vertical_spacing = vertical_spacing;
    }

    /**
     * @param horizontal_spacing Pixels between items, horizontally
     * @param vertical_spacing Pixels between items, vertically
     */
    public LayoutParams(int horizontal_spacing, int vertical_spacing) {
        super(0, 0);
        this.horizontal_spacing = horizontal_spacing;
        this.vertical_spacing = vertical_spacing;
    }
}

public FlowLayout(Context context) {
    super(context);
}

public FlowLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    assert (MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED);

    final int width = MeasureSpec.getSize(widthMeasureSpec) - getPaddingLeft() - getPaddingRight();
    int height = MeasureSpec.getSize(heightMeasureSpec) - getPaddingTop() - getPaddingBottom();
    final int count = getChildCount();
    int line_height = 0;

    int xpos = getPaddingLeft();
    int ypos = getPaddingTop();

    int childHeightMeasureSpec;
    if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, MeasureSpec.AT_MOST);
    } else {
        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
    }


    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            child.measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.AT_MOST), childHeightMeasureSpec);
            final int childw = child.getMeasuredWidth();
            line_height = Math.max(line_height, child.getMeasuredHeight() + lp.vertical_spacing);

            if (xpos + childw > width) {
                xpos = getPaddingLeft();
                ypos += line_height;
            }

            xpos += childw + lp.horizontal_spacing;
        }
    }
    this.line_height = line_height;

    if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.UNSPECIFIED) {
        height = ypos + line_height;

    } else if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.AT_MOST) {
        if (ypos + line_height < height) {
            height = ypos + line_height;
        }
    }
    setMeasuredDimension(width, height);
}

@Override
protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(1, 1); // default of 1px spacing
}

@Override
protected android.view.ViewGroup.LayoutParams generateLayoutParams(
        android.view.ViewGroup.LayoutParams p) {
    return new LayoutParams(1, 1, p);
}

@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
    if (p instanceof LayoutParams) {
        return true;
    }
    return false;
}

@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
    final int width = r - l;
    int xpos = getPaddingLeft();
    int ypos = getPaddingTop();

    int lastHorizontalSpacing = 0;
    int rowStartIdx = 0;

    for (int i = 0; i < count; i++) {
        final View child = getChildAt(i);
        if (child.getVisibility() != GONE) {
            final int childw = child.getMeasuredWidth();
            final int childh = child.getMeasuredHeight();
            final LayoutParams lp = (LayoutParams) child.getLayoutParams();
            if (xpos + childw > width) {
                final int freeSpace = width - xpos + lastHorizontalSpacing;
                xpos = getPaddingLeft() + freeSpace / 2;

                for (int j = rowStartIdx; j < i; ++j) {
                    final View drawChild = getChildAt(j);
                    drawChild.layout(xpos, ypos, xpos + drawChild.getMeasuredWidth(), ypos + drawChild.getMeasuredHeight());
                    xpos += drawChild.getMeasuredWidth() + ((LayoutParams)drawChild.getLayoutParams()).horizontal_spacing;
                }

                lastHorizontalSpacing = 0;
                xpos = getPaddingLeft();
                ypos += line_height;
                rowStartIdx = i;
            } 

            child.layout(xpos, ypos, xpos + childw, ypos + childh);
            xpos += childw + lp.horizontal_spacing;
            lastHorizontalSpacing = lp.horizontal_spacing;
        }
    }

    if (rowStartIdx < count) {
        final int freeSpace = width - xpos + lastHorizontalSpacing;
        xpos = getPaddingLeft() + freeSpace / 2;

        for (int j = rowStartIdx; j < count; ++j) {
            final View drawChild = getChildAt(j);
            drawChild.layout(xpos, ypos, xpos + drawChild.getMeasuredWidth(), ypos + drawChild.getMeasuredHeight());
            xpos += drawChild.getMeasuredWidth() + ((LayoutParams)drawChild.getLayoutParams()).horizontal_spacing;
        }
    }
}
}

Java Android 的换行小部件布局

提问by Henrik Gustafsson

采纳答案by Lukas Novak

回答by Will

回答by Henrik Gustafsson

回答by Mark

回答by Micah Hainline

回答by Melinda Green

回答by Aurélien Guillard

回答by Henry

回答by Mohsen Afshin

回答by Muhammad Aamir Ali

回答by Ernestas Vaiciukevi?ius

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最近更新

标签

Java Android 的换行小部件布局

提问by Henrik Gustafsson

采纳答案by Lukas Novak

回答by Will

回答by Henrik Gustafsson

回答by Mark

回答by Micah Hainline

回答by Melinda Green

回答by Aurélien Guillard

回答by Henry

回答by Mohsen Afshin

回答by Muhammad Aamir Ali

回答by Ernestas Vaiciukevi?ius

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