getID for button returns -1

Question

public class Test extends Activity { 
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     Button b = new Button(this); 
     String id = Integer.toString(b.getId()); 
     Toast.makeText(getApplicationContext(), id, 1).show(); 
    } 
} 

爲什麼它返回-1？

Answer 1

因爲這是ID視圖是在您自己創建它們時給出的。

只需設置ID與

b.setId(int) 

http://developer.android.com/reference/android/widget/Button.html