android中的延迟动作

Question

代码实现预期功能是：在应用开始五秒钟后，变化imageView的图片。

public class MainActivity extends Activity {
ImageView screen;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    screen=(ImageView)findViewById(R.id.imageView1);

    screen.setImageResource(R.drawable.ic_launcher);

}
}

应该怎么成功延迟？谢谢帮忙

Answer 1

可以通过Handler来实现
Handler定义：

class ReadDataHandler extends Handler{
    @Override
    public void handleMessage(Message msg) {
        // TODO Auto-generated method stub
        updateBlackBackground();
        updateWhiteBackground();
        super.handleMessage(msg);
    }
}

Handler使用：

private ReadDataHandler mReadDataHandler;
mReadDataHandler = new ReadDataHandler();

需要处理时发送消息：

Message lMessage = new Message();
mReadDataHandler.sendMessageDelayed(lMessage, 5000);