Question

我想添加View，但它无法显示View并且在运行时未发现错误

protected void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.relative_null);
    RelativeLayout relativeLayout= (RelativeLayout)
            getLayoutInflater().inflate(R.layout.relative_null,null);
    TextView tv = new TextView(this);
    tv.setText("Hello World");
    RelativeLayout.LayoutParams layoutParams=new RelativeLayout.LayoutParams
            (80,80);
    layoutParams.addRule(RelativeLayout.RIGHT_OF,R.id.button1);
    layoutParams.addRule(RelativeLayout.BELOW,R.id.button1);
    tv.setLayoutParams(layoutParams);
    relativeLayout.addView(tv);
}

这是我的xml R.layout.relative_null

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"   
    android:layout_height="match_parent"
    android:id="@+id/myRelativeLayout">

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="New Button"
    android:id="@+id/button1"/>
</RelativeLayout>

Answer 1

您并没有正确添加textview。您正在将textview添加到您自己夸大的布局中。该布局与您通过setContentView()看到的布局不同。你不需要给另一个人充气。这是更新后的代码：

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.relative_null);
    RelativeLayout relativeLayout= (RelativeLayout) findViewById(R.id.myRelativeLayout);

    // tv init below
    TextView tv = new TextView(this);
    tv.setText("Hello World");
    RelativeLayout.LayoutParams layoutParams=new RelativeLayout.LayoutParams
            (80,80); 
    layoutParams.addRule(RelativeLayout.RIGHT_OF,R.id.button1);
    layoutParams.addRule(RelativeLayout.BELOW,R.id.button1);
    tv.setLayoutParams(layoutParams);

    relativeLayout.addView(tv);
}

当inflate和setContentview相同的布局时，addview会失败

1 个答案: