Handler.postDelayed v / s Runnable.run。 可以调用.run而不是.postDelayed吗？

Question

I was trying to implement a looping Runnable . The example I've found seems to use the following idea to kick-start the runnable.

        handler = new Handler();
        final Runnable r = new Runnable() {
            public void run() {
                handler.postDelayed(this, 10000);
                doIt();
                count ++;
            }
        };
        r.run();// what I prefer
//      handler.postDelayed(r, 1000);//their idea

I prefer using the call to the run() method to start the Runnable . What would be the possible troubles that I could get into if any by a direct call to run() !

Thanks! :)

Answer 1

If you call r.run() , the Runnable will be executed immediately. But if you call handler.postDelayed(r, 1000); as they recommended, the Runnable will not be executed until 1s is past. So, this is the first point. Second, why don't you use the Thread Loop merchanism provided by Android , namely Handler AsyncTask HandlerThread for the sake that Android supports it very well?

Answer 2

I prefer using the call to the run() method to start the Runnable.

OK.

What would be the possible troubles that I could get into if any by a direct call to run()!

The first pass through run() would happen immediately, as opposed to your commented-out code, which would cause the first pass through run() to occur ~1000ms from now.

However, I would dump the Handler . postDelayed() is also a method on View , so just use some widget in your UI.