Android AlertDialog 直到 bluetoothsocket.connect() 之后才会显示

Question

I have an AlertDialog that is set to display before bluetoothsocket.connect() , which is a blocking method. However, the AlertDialog doesn't show until after the bluetoothsocket.connect() method finishes.

myalertdialog.show();
// Dialog is not shown.
mybluetoothsocket.connect();  // This blocks and takes a few seconds to run.
// Dialog is shown.

What could be causing this behavior?

Answer 1

If your bluetoothsocket.connect() is blocking, which you said it is, you should put it out of the UI main thread. What you can do is put it inside an AsyncTask . Your myalertdialog.show() can be executed right before calling your AsyncTask . Then call myalertdialog.hide() in AsyncTask 's onPostExecute() .

Answer 2

Since bluetoothsocket.connect block UI calls its on separate thread

final Handler mHandler = new Handler();// This statement is to be called by the main thread

                myalertdialog.show();

                Thread t = new Thread(
                        new Runnable(){

                            public void run()
                            {

                                mybluetoothsocket.connect(); 
                                mHandler.post(new Runnable(){

                                    public void run()
                                    {
                                        //ProgressDialog.dismiss();
                                    }
                                });
                            }});
                t.start();