setContentView通過使用擴展視圖類

Question

我正在使用擴展視圖來設置活動的內容。發生了什麼，它顯示空白活動。而不是設置文本。

public class ThreadCheck extends Activity{ 
     MyView view; 
     /* (non-Javadoc) 
     * @see android.app.Activity#onCreate(android.os.Bundle) 
     */ 
     @Override 
     protected void onCreate(Bundle savedInstanceState) { 
      // TODO Auto-generated method stub 
      super.onCreate(savedInstanceState); 
      Context ctx = getApplicationContext(); 
      view=new MyView(ctx); 
      setContentView(view); 
     } 
    } 

---

public class MyView extends View{ 
      TextView tvThread; 
      public MyView(Context context) { 
       super(context); 
       tvThread=new TextView(context); 
       tvThread.setText("Hello This Is Myview"); 
       // TODO Auto-generated constructor stub 
      } 

     } 

Answer 1

更改此

view=new MyView(ctx); 

到

view=new MyView(ThreadCheck.this); 

，並切換到

public class MyView extends TextView{ 

    public MyView(Context context) { 
     super(context); 
     this.setText("Hello This Is Myview"); 
    } 

} 

編輯：在評論中的問題。您需要添加視圖的ViewGroup。

public class MyView extends RelativeLayout{ 

     public MyView(Context context) { 
      super(context); 


      RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 
      this.setLayoutParams(layoutParams); 

      RelativeLayout.LayoutParams params1 = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT); 

      TextView tv = new TextView(context); 
      tv.setText("hello"); 
      tv.setId(1); 

      Button b = new Button(context); 
      params1.addRule(RelativeLayout.BELOW, tv.getId()); 
      b.setText("Hi"); 
      b.setId(2); 

      this.addView(tv); 
      this.addView(b, params1); 

     } 
    }