进度条完成后执行某些操作

Question

I want to toast (or show a dialog) when progressbar ends. I tried to do this with if in run() method, but it causes the following error:

Can't create handler inside thread that has not called Looper.prepare()

how can I do that?

This is my code:

@Override
public void run() {
    int myProgress = 0, Speed = 50;
    ProgressBar myProgressBar = (ProgressBar) findViewById(R.id.progressbar);

    while (myProgress<750){
        try{
            Thread.sleep(Speed);
            myProgress++;
            if (myProgressBar != null) {
                myProgressBar.setProgress(myProgress);
            }
        }
        catch(Throwable t){ }
    }
}

Answer 1

   runOnUiThread(new Runnable() {
      public void run() {
          //your code here 
      }
   });

Change like this.

runOnUiThread(new Runnable() {
  public void run() {
    int myProgress = 0, Speed = 50;
    ProgressBar myProgressBar = (ProgressBar) findViewById(R.id.progressbar);

    while (myProgress<750){
    try{
        Thread.sleep(Speed);
        myProgress++;
        if (myProgressBar != null) {
            myProgressBar.setProgress(myProgress);
        }
    }
    catch(Throwable t){ }
}      
}
});

Worker threads are meant for doing background tasks and you can't show anything on UI within a worker thread unless you call method like runOnUiThread. If you try to show anything on UI thread without calling runOnUiThread, there will be a java.lang.RuntimeException. Tell me if you still face any problem.

Answer 2

I tried this and it works now:

public void run() {
    int myProgress = 0, Speed = 50;
    ProgressBar myProgressBar = (ProgressBar) findViewById(R.id.progressbar);
    while (myProgress<750){
        try{
            Thread.sleep(Speed);
            myProgress++;
            if (myProgressBar != null) {
                myProgressBar.setProgress(myProgress);
            }
        }
        catch(Throwable t){ }
}

final int finalMyProgress = myProgress;

    runOnUiThread(new Runnable() {
        @Override
        public void run() {
            if (finalMyProgress == 750)
                Toast.makeText(word_guess2.this, "hi", Toast.LENGTH_SHORT).show();
        }
    });
}