Android ViewPager 不支持 layout_height = wrap_content

ViewPager not supporting layout_height = wrap_content

提问by Andrei Stalbe

I'm building an android application with the following layout.

我正在构建一个具有以下布局的 android 应用程序。

It's already known that layout_height="wrap_content"doesn't work for the ViewPager.

众所周知，这layout_height="wrap_content"不适用于 ViewPager。

My question is how to change it dynamically. The content of the ViewPager is inflated from two xml layouts, vp_statistics.xml and vp_campaigns.xml.

我的问题是如何动态更改它。ViewPager 的内容从两个 xml 布局膨胀，vp_statistics.xml and vp_campaigns.xml.

here's the xml for the ViewPager

这是 ViewPager 的 xml

<LinearLayout
            android:id="@+id/topcontent_wrapper"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="vertical" >
</LinearLayout>

<LinearLayout
            android:id="@+id/viewpager_wrapper"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:orientation="vertical" >

            <android.support.v4.view.ViewPager
                android:id="@+id/viewpager"
                android:layout_width="match_parent"
                android:layout_height="wrap_content" />
</LinearLayout>

Here's the code for my PagerAdapter

这是我的 PagerAdapter 的代码

class MyPagerAdapter extends PagerAdapter{

@Override
public int getCount() {
    // TODO Auto-generated method stub
    return 2;
}

public Object instantiateItem(View collection, int pos){
    LayoutInflater inflater =     (LayoutInflater)collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    int resId = 0;
    switch(pos){
    case 0:
        resId = R.layout.vp_statistics;
        break;
    case 1:
        resId = R.layout.vp_campaigns;
        break;
    }

    View view = inflater.inflate(resId, null);


    ((ViewPager)collection).addView(view, 0);

    return view;
}

@Override
public void destroyItem(ViewGroup container, int position, Object object) {
    // TODO Auto-generated method stub
    ((ViewPager)container).removeView((View)object);
}

@Override
public boolean isViewFromObject(View arg0, Object arg1) {
    // TODO Auto-generated method stub
    return arg0 == ((View)arg1);
}

@Override
public Parcelable saveState() {
    // TODO Auto-generated method stub
    return null;
}

}

and inside my onCreate() mthod of the Activity class:

在 Activity 类的 onCreate() 方法中：

MyPagerAdapter adapter = new MyPagerAdapter();
ViewPager viewPager = (ViewPager)findViewById(R.id.viewpager);
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);

Is there a way to get the height of the vp_statistics.xmland vp_campaigns.xmllayouts and assign it dynamically to ViewPager (@id/viewpager)every time the instantiateItem()object gets called?

有没有办法在每次调用对象时获取vp_statistics.xml和vp_campaigns.xml布局的高度并动态分配它？ViewPager (@id/viewpager)instantiateItem()

回答by josephus

1. Add a weightSum=2attribute to the parent LinearLayout, and set orientation=vertical.
2. Set the top child LinearLayout's layout_weight=1. Also, set layout_height=0dip
3. Wrap the ViewPager into another LinearLayoutwith layout_weight=1and layout_height=0dip

1. weightSum=2向 parent添加一个属性LinearLayout，并设置orientation=vertical.
2. 设置顶级孩子 LinearLayout 的layout_weight=1. 另外，设置layout_height=0dip
3. LinearLayout用layout_weight=1和将 ViewPager 包装成另一个layout_height=0dip

回答by cybergen

I answered a similar question here.

我在这里回答了一个类似的问题。

The solution extendsViewPager to override onMeasure()to make wrap_contentjust work for the height.

该解决方案扩展ViewPager 以覆盖onMeasure()以使其wrap_content仅适用于高度。

回答by virusss8

use 0dpinstead of wrap_content, and for dynamically change that

使用0dp代替wrap_content, 并动态更改它

pager = new ViewPager(this);
        pager.setLayoutParams(new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.WRAP_CONTENT));

回答by OceanLife

In order to assign different screen real estate to each linear layout try using the layout_weightparameter. You can reassign this in-code to achieve this 'dynamic' weighting change. Overview herewith plenty of Google-able examples of how to achieve the weight layouts in code...

为了为每个线性布局分配不同的屏幕空间，请尝试使用该layout_weight参数。您可以重新分配此代码以实现此“动态”权重更改。此处概述了大量有关如何在代码中实现权重布局的 Google 示例...

回答by franta kocourek

Use RelativeLayout:

使用相对布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

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

    </LinearLayout>

    <android.support.v4.view.ViewPager
        android:id="@+id/pager"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:layout_below="@+id/layout" >

    </android.support.v4.view.ViewPager>

</RelativeLayout>