Question

假设我在RelativeLayout中有两个按钮。顶部标有“一个”的按钮和“一个”下面标有“三”的按钮。布局定义如下。

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:id="@+id/mainContainer"
    tools:context=".MainActivity" >

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tvOne"
        android:layout_centerHorizontal="true"
        android:layout_alignParentTop="true"
        android:text="One" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tvThree"
        android:layout_centerHorizontal="true"
        android:layout_below="@id/tvOne"
        android:text="Three" />
</RelativeLayout>

因此，我在onCreate的{{1}}中编写了一些代码，以动态创建MainActivity，并将其插入到1到3之间。但它没有用。有什么我想念的吗？我创建这个问题是我所遇到的更大问题的简化版本，所以我不能接受清除布局并动态插入一个二和三。

Button

Answer 1

我正在检查工作代码。

public class Main extends Activity {

    Context ctx;
    RelativeLayout rlayMainContainer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ctx = this;

        rlayMainContainer = (RelativeLayout) findViewById(R.id.mainContainer);
        Button one = (Button) findViewById(R.id.tvOne);
        Button three = (Button) findViewById(R.id.tvThree);


        // adding button two dynamically
        Button two = new Button(ctx);
        two.setText("hello");
        two.setId(12);

        RelativeLayout.LayoutParams lpSecond = new RelativeLayout.LayoutParams(
                LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
        lpSecond.addRule(RelativeLayout.CENTER_HORIZONTAL);
        lpSecond.addRule(RelativeLayout.BELOW, one.getId());

        rlayMainContainer.addView(two, lpSecond);

        //align button three below button two

        RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) three
                .getLayoutParams();

        params.addRule(RelativeLayout.BELOW, two.getId());

        three.setLayoutParams(params);
    }
}

enter image description here

Answer 2

实际上，“两个”按钮就在那里，但你看不到因为它的高度= 0。这些代码行使“两个”按钮的高度= 0

params.addRule(RelativeLayout.BELOW, one.getId());
params.addRule(RelativeLayout.ABOVE, three.getId());

是的，“两个”按钮layoutParams表示它必须介于“一”和“三”之间，但这些按钮之间没有剩余空间 - ＆gt;没有高度。

要解决此问题，您需要删除设置“两个”高于“三”的行并添加代码以指示“三”现在低于“两个”

        final int WC = RelativeLayout.LayoutParams.WRAP_CONTENT;
        RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
                WC, WC);
        params.addRule(RelativeLayout.CENTER_HORIZONTAL, RelativeLayout.TRUE);
        params.addRule(RelativeLayout.BELOW, one.getId());

        two.setLayoutParams(params);

        // Add button number two to the activity.
        RelativeLayout rl = (RelativeLayout) findViewById(R.id.mainContainer);
        rl.addView(two);

        two.setId(1);
        params = (LayoutParams) three.getLayoutParams();
        params.addRule(RelativeLayout.BELOW, two.getId());
        three.setLayoutParams(params);

RelativeLayout在另外两个之间插入视图

2 个答案: