Horizo​​ntalscrollView 内 LinearLayout 中的片段宽度问题

Question

我有一个 Horizo​​ntalscrollview，里面是水平 LinearLayout。 我试图将片段动态添加到线性布局中。虽然我将片段宽度设置为“match_parent”，但片段并未填充屏幕宽度。

这是我的 MainActivity xml 布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">

    <HorizontalScrollView
        android:layout_width="match_parent"
        android:layout_height="400dp"
        android:fillViewport="true"
        android:id="@+id/baseScrollView">

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

        </LinearLayout>

    </HorizontalScrollView>


   <Button
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:id="@+id/btnNext"
       android:text="Next Page"/>

</LinearLayout>

这是我的 MainActivity 代码

Button btnNext;
CustomHorizontalScrollView baseScrollView;
LinearLayout scrollViewLayout;
boolean isFragment1Added = false;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    btnNext = (Button) findViewById(R.id.btnNext);
    scrollViewLayout = (LinearLayout) findViewById(R.id.scrollViewLayout);

    btnNext.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(isFragment1Added){
                isFragment1Added = false;
                addCustomFragment(new Fragment2(), "fragment_2");
            }else{
                isFragment1Added = true;
                addCustomFragment(new Fragment1(), "fragment_1");
            }

        }
    });
}

public void addCustomFragment(Fragment fragmentView, String tag) {

    FragmentTransaction viewTransaction = getFragmentManager().beginTransaction();
    viewTransaction.add(R.id.scrollViewLayout, fragmentView, tag);
    viewTransaction.commit();
}

这里是fragment1.xml。 fragment2 与 fragment1 类似。

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/holo_red_dark"
tools:context="com.uobtravelplanners.horizontalscrollviewtest.Fragment1">

<!-- TODO: Update blank fragment layout -->
<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="FRAGMENT 1"
    android:textSize="50sp"
    android:gravity="center"/>

</FrameLayout>

here's the screenshot

Answer 1

1. 将scrollViewLayout的layout_width设置为wrap_content
2. 通过编程将片段的宽度设置为屏幕宽度

编辑 1

Get screen dimensions in pixels

首先，根据这篇帖子获取屏幕宽度。

然后在onCreateView方法中设置layout_width，如

    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        // get screen width
        int screenWidth = ...
        // get the root view of the fragment
        View root = inflater.inflate(R.id.your_layout, container, false);
        // set layout_width through LayoutParams
        root.setLayoutParams(new ViewGroup.LayoutParams(screenWidth, ViewGroup.LayoutParams.MATCH_PARENT));
        return root;
    }