按钮的getID返回-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();
    }
}

为什么它会返回-1？

Answer 1

因为这是您自己创建ID视图时所给出的。

只需使用

设置ID即可

b.setId(int)

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