How to make app wait and then start activity or go

问题:

I want my activity to show a screen for 3 seconds, then go back to previous screen. But when i use

protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.welcome_layout);
        TextView tvResult = (TextView)findViewById(R.id.textView1)
        Thread.sleep(3000);
            Intent i = new Intent(this,myActivity.class);
            startActivity(i);

But unfortunately, this does not work. This doesent show the activity waits 3 seconds and goes back. However, i want it to show its contents before going back. How can i do it ?

回答1:

You should remove this Thread.sleep(3000); which block the ui thread. You should never block the ui thred. You can use a Handler postDelayed with a delay and then startActivtiy.

Handler handler = new Handler();
handler.postDelayed(new Runnable(){
@Override
  public void run(){
   // do something
 }
 }, 3000);

To go back to previous Activity you can call finish().

Also if you need to go back to the previous activity for 3 seconds why do you need

Intent i = new Intent(this,myActivity.class);
startActivity(i);

Calling finish() will do the job

回答2:

This is not the recommended way to do this. Using Thread.sleep you basically force the activity to wait 3000 seconds before can move on. So anything in the activity will work until 3 seconds are passed.

You could do this: edited: now it works well.

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.welcome_layout);
    TextView tvResult = (TextView)findViewById(R.id.textView1)
    new Thread(new Runnable()
    {
        @Override
        public void run()
        {
            try
            {
                Thread.sleep(3000);
                Intent i = new Intent(getApplicationContext(), myActivity.class);
                startActivity(i);
            }
            catch (InterruptedException e)
            {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }).start();
}