setBackgroundColor（INT顏色）和RelativeLayout的

Question

，當我用這個XML文件...

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/RelativeLayout1" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:background="#FF0000" 

tools:context=".MainActivity" > 

<TextView 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"   
    android:text="@string/hello_world" /> 

</RelativeLayout> 

..我看到，背景色包裝內容

http://img716.imageshack.us/img716/8225/rlayout.jpg

但如果我寫這篇文章的RelativeLayout通過代碼...

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

    RelativeLayout layout = new RelativeLayout(this); 

    RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
      RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT); 


    layout.setBackgroundColor(Color.parseColor("#FF0000")); 

    TextView text = new TextView(this); 
    text.setText("Hello world"); 

    //Añado texto 
    layout.addView(text); 

    layout.setLayoutParams(params); 

    setContentView(layout); 
} 

...我看到背景色m ATCH父母，而不是包裝內容

http://img404.imageshack.us/img404/1427/rlayoutfull.jpg

任何想法？

謝謝！

Answer 1

你永遠不會設置佈局PARAMS：

layout.setLayoutParams(params); 

，我認爲你應該把：

TextView text = new TextView(this); 
text.setText("Hello world"); 

和所有其他視圖中，您將您之前添加到您的佈局設置佈局params，否則將沒有內容可以繞回。

編輯：

當你設置發生了什麼：

tried to replace between the two: 

RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
     RelativeLayout.LayoutParams.WRAP_CONTENT, RelativeLayout.LayoutParams.WRAP_CONTENT); 

？