Java 如何在android中设置包装内容的最大高度？

How to set a maximum height with wrap content in android?

提问by omega

In android, how can you create a scroll view that's got a max height, and wrap contents, basically it wraps the content vertically, but has a maximum height?

在android中，如何创建一个具有最大高度的滚动视图并包裹内容，基本上它垂直包裹内容，但具有最大高度？

I tried

我试过

<ScrollView 
     android:id="@+id/scrollView1"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
         android:maxHeight="200dp"
     android:layout_alignParentBottom="true" >

    <LinearLayout
        android:id="@+id/maincontainer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

    </LinearLayout>
</ScrollView>

But this isn't working?

但这行不通？

回答by Abhishek Birdawade

Here you can set height of your Scrollview like this -:

在这里，您可以像这样设置 Scrollview 的高度 -：

<ScrollView 
 android:id="@+id/scrollView1"
 android:layout_width="match_parent"
 android:layout_height="200dp"
 android:layout_alignParentBottom="true" >

           <LinearLayout
            android:id="@+id/maincontainer"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

           </LinearLayout>
</ScrollView>

回答by JMPergar

I've extended ScrollView and added code to implement this feature:

我扩展了 ScrollView 并添加了代码来实现此功能：

https://gist.github.com/JMPergar/439aaa3249fa184c7c0c

https://gist.github.com/JMPergar/439aaa3249fa184c7c0c

I hope that be useful.

我希望这是有用的。

回答by harmashalex

You can do it programmatically.

您可以以编程方式进行。

 private static class OnViewGlobalLayoutListener implements ViewTreeObserver.OnGlobalLayoutListener {
    private final static int maxHeight = 130;
    private View view;

    public OnViewGlobalLayoutListener(View view) {
        this.view = view;
    }

    @Override
    public void onGlobalLayout() {
        if (view.getHeight() > maxHeight)
            view.getLayoutParams().height = maxHeight;
    }
}

And add listener to the view:

并向视图添加侦听器：

view.getViewTreeObserver()
                  .addOnGlobalLayoutListener(new OnViewGlobalLayoutListener(view));

Listener will call method onGlobalLayout(), when view height will be changed.

当视图高度发生变化时，侦听器将调用方法 onGlobalLayout()。

回答by babay

you can add this to any view (override onMeasure in a class inherited from a view)

您可以将此添加到任何视图（覆盖从视图继承的类中的 onMeasure）

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    if (maxHeight > 0){
        int hSize = MeasureSpec.getSize(heightMeasureSpec);
        int hMode = MeasureSpec.getMode(heightMeasureSpec);

        switch (hMode){
            case MeasureSpec.AT_MOST:
                heightMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(hSize, maxHeight), MeasureSpec.AT_MOST);
                break;
            case MeasureSpec.UNSPECIFIED:
                heightMeasureSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.AT_MOST);
                break;
            case MeasureSpec.EXACTLY:
                heightMeasureSpec = MeasureSpec.makeMeasureSpec(Math.min(hSize, maxHeight), MeasureSpec.EXACTLY);
                break;
        }
    }

    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

回答by Rasool_sof

for set scrollview height you must use 2 linerlayout inside together and then set scrool view as them child then set middle linerlayout layout:height for limit scrollview height.

要设置滚动视图高度，您必须将 2 个 linerlayout 一起使用，然后将滚动视图设置为它们的孩子，然后设置中间 linerlayout layout:height 以限制滚动视图高度。

回答by Yash Krishan

1.) Create a class to handle setting maximum height to what is passed by the user:

1.) 创建一个类来处理将最大高度设置为用户传递的内容：

public class OnViewGlobalLayoutListener implements ViewTreeObserver.OnGlobalLayoutListener {


private Context context;
private int maxHeight;
private View view;

public OnViewGlobalLayoutListener(View view, int maxHeight, Context context) {
    this.context = context;
    this.view = view;
    this.maxHeight = dpToPx(maxHeight);
}

@Override
public void onGlobalLayout() {
    if (view.getHeight() > maxHeight) {
        ViewGroup.LayoutParams params = view.getLayoutParams();
        params.height = maxHeight;
        view.setLayoutParams(params);
    }
}

public int pxToDp(int px) {
    DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
    int dp = Math.round(px / (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
    return dp;
}

public int dpToPx(int dp) {
    DisplayMetrics displayMetrics = context.getResources().getDisplayMetrics();
    int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
    return px;
}
}

2.) Attach this to the view and pass the maximum height in DP:

2.) 将此附加到视图并通过 DP 中的最大高度：

messageBody.getViewTreeObserver()
            .addOnGlobalLayoutListener(
             new OnViewGlobalLayoutListener(messageBody, 256, context)
             );

Thanks to @harmashalex for the inspiration. I made modifications to as setting the layout params didn't work by @harma's code. Also, dp-to-px conversion is necessary to offload wondering about it.

感谢@harmashalex 的启发。我进行了修改，因为@harma 的代码设置布局参数不起作用。此外，dp 到 px 的转换对于减轻对它的疑惑是必要的。