android - match_parent 不工作 xml android

Question

我正在尝试制作会改变部分上下文的按钮，但 match_parent 无法正常工作。

得到java主文件:

class public MainActivity extends ActionBarActivity {

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

        getSupportActionBar().setDisplayShowHomeEnabled(true);
        getSupportActionBar().setIcon(R.drawable.ic_launcher);

        Button bn1 = (Button) findViewById(R.id.navbar_1);
        Button bn2 = (Button) findViewById(R.id.navbar_2);

        bn1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                FragmentMeters fr = new FragmentMeters();
                FragmentManager fm = getFragmentManager();
                FragmentTransaction ft = fm.beginTransaction();
                ft.replace(R.id.layout_to_replace, fr);
                ft.commit();

            }
        });

        bn2.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                FragmentValues fr = new FragmentValues();
                FragmentManager fm = getFragmentManager();
                FragmentTransaction ft = fm.beginTransaction();
                ft.replace(R.id.layout_to_replace, fr);
                ft.commit();



            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

}

然后是另一个 java 类 FragmentMeters(和类似的 FragmentValues):

public class FragmentMeters extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_meters, null);

        return view;
    }

}

还有主要的 XML，像这样:

<LinearLayout
    android:id="@+id/navbar"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="82dp"
    android:background="@color/highlighted_text_material_dark"
    android:weightSum="4">

    <Button
        android:id="@+id/navbar_1"
        android:text="@string/navbar_1"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:textSize="13sp"
        android:background="@android:color/transparent"
        android:gravity="bottom|center_horizontal" />
    <Button
        android:id="@+id/navbar_2"
        android:text="@string/navbar_2"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:textSize="13sp"
        android:background="@android:color/transparent"
        android:gravity="bottom|center_horizontal" />
</LinearLayout>

<LinearLayout
    android:id="@+id/layout_to_replace"
    android:orientation="horizontal"
    android:layout_below="@+id/navbar"
    android:layout_width="match_parent"
    android:background="@color/dim_foreground_disabled_material_dark"
    android:layout_height="82dp"
    android:weightSum="4"/>

我正在尝试用这个 fragment_meters.xml 替换 LinearLayout (id="layout_to_replace"):

 <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="horizontal"
        android:layout_below="@+id/navbar"
        android:layout_width="match_parent"
        android:layout_height="82dp"
        android:background="@color/dim_foreground_disabled_material_dark"
        android:weightSum="4">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="METERS"/>

    </LinearLayout>

但是我得到了这个:

而不是匹配父级的宽度/高度。

Answer 1

我知道这个问题，在某些情况下，当展开布局时，参数 layout_width 和 layout_height 会更改为包装内容。

我建议你在充气后手动设置布局参数:

View view = inflater.inflate(R.layout.fragment_meters, null);
view.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));

(高度放你想要的)