假设你有两个activity 分别LoadingScreen activity (loadingscreen.xml layout), 和 Main activity (main.xml).

然后在LoadingScreen中

ProgressBar pb = (ProgressBar)findViewById(R.id.ProgressBar01);

/* Setting up handler for ProgressBar */
         pbHandle = new Handler(){
              @Override

public void handleMessage(Message msg) {
                 /* get the value from the Message */
                 int progress = msg.arg1;
                 pb.setProgress(progress); 
                }
               };

 然后在主activity中

/* Creating a message */
Message progressMsg = new Message();
                 progressMsg.arg1 = progress();
                 /* Sending the message */
                 pbHandle.sendMessage(progressMsg);