如何显示几秒钟的textview然后使其隐藏？

Question

这个网站是最好的,它帮了我很多...我是创建android applecation的初学者.这是我第一次在这里问一个问题..我的问题是如何显示一个textview只是5秒钟让它消失..当我搜索时我发现了一些代码,但我不知道如何使用它或者我使用它以错误的方式..所以任何人都可以给我一个非常简单的例子,如何做到这一点？我真的很感激你的帮助...... >>(我不希望文字消失,我希望洞文本视图消失)

Answer 1

使用AsyncTask:

new AsyncTask<Void, Void, Void>()
{

  protected Void doInBackground(Void... params)
  {
    Thread.sleep(5000);                   // sleep 5 seconds
  }

  protected void onPostExecute (Void result)
  {
    // fade out view nicely
    AlphaAnimation alphaAnim = new AlphaAnimation(1.0f,0.0f);
    alphaAnim.setDuration(400);
    alphaAnim.setAnimationListener(new AnimationListener()
    {
     public void onAnimationEnd(Animation animation)
     {
       // make invisible when animation completes, you could also remove the view from the layout
       myTextView.setVisibility(View.INVISIBLE);
     }
    });

    myTextView.startAnimation(alphaAnim);


  }
}.execute();

或者,更好的是,只使用动画:

编辑(感谢@pkk的建议):

// fade out view nicely after 5 seconds
AlphaAnimation alphaAnim = new AlphaAnimation(1.0f,0.0f);
alphaAnim.setStartOffset(5000);                        // start in 5 seconds
alphaAnim.setDuration(400);
alphaAnim.setAnimationListener(new AnimationListener()
{
 public void onAnimationEnd(Animation animation)
 {
   // make invisible when animation completes, you could also remove the view from the layout
   myTextView.setVisibility(View.INVISIBLE);
 }
});

myTextView.setAnimation(alphaAnim);

Answer 2

一种方法是使用CountDownTimer,如果你想要显示计时器

public void onCreate(...){
...
timer = new MyCountDown(5000, 1000);
}

private class MyCountDown extends CountDownTimer
{
    long duration, interval;
    public MyCountDown(long millisInFuture, long countDownInterval) {
        super(millisInFuture, countDownInterval);
        // TODO Auto-generated constructor stub
        start();
    }

    @Override
    public void onFinish() {
        textView1.setVisibility(View.INVISIBLE);    
    }

    @Override
    public void onTick(long duration) { 
             // could set text for a timer here     
    }   
}

您也可以使用TimerTask.

这是一个很好的例子TimerTask

还有其他各种方式.您可以搜索文档或SO来决定哪种最适合您的需求

用TimerTask示例编辑

  Timer t = new Timer(false);
  t.schedule(new TimerTask() {
  @Override
  public void run() {
       runOnUiThread(new Runnable() {
            public void run() {
                txt.setVisibility(View.INVISIBLE);
            }
        });
    }
}, 5000);