java - TextView 作为属性？

Question

我想使用我的 TextView 作为属性

private TextView up = (TextView) findViewById(R.id.tv_up);
private TextView mid = (TextView) findViewById(R.id.tv_mid);
private TextView down = (TextView) findViewById(R.id.tv_down);

而不是永远定义它:

public void onButtonClickUp(View v) {
        TextView up = (TextView) findViewById(R.id.tv_up);
        TextView mid = (TextView) findViewById(R.id.tv_mid);
        TextView down = (TextView) findViewById(R.id.tv_down);
        <..>
}

public void onButtonClickDown(View v) {
        TextView up = (TextView) findViewById(R.id.tv_up);
        TextView mid = (TextView) findViewById(R.id.tv_mid);
        TextView down = (TextView) findViewById(R.id.tv_down);
        <..>
}

上面的方法在我的安卓设备上产生了一个force close error。如何解决这个问题或者这通常是可能的吗？

谢谢!

Answer 1

public class TestActivity extends Activity {

    private TextView up;
    private TextView mid;
    private TextView down;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

     up = (TextView) findViewById(R.id.tv_up);
     mid = (TextView) findViewById(R.id.tv_mid);
     down = (TextView) findViewById(R.id.tv_down);

}

我不确定您的应用程序崩溃的原因，但您可以通过像这样声明/分配您的小部件来避免很多麻烦......整个 Activity 只需一次。