android - Android Studio。线程休眠后应用崩溃

Question

我希望能够在3秒钟后更改“文本 View ”的设置文本。为此，我创建了一条try catch语句，并告诉线程在执行以下代码之前先休眠3000毫秒。不幸的是，当我运行该应用程序时，该程序仅等待3秒钟，然后崩溃。任何帮助将不胜感激。

    Runnable runnable3 = new Runnable() {

        @Override
        public void run() {
            TextView sup_txt3 = findViewById(R.id.sup_txt3);
            sup_txt3.setText("Ooooohhhh this is very hard. I am receiving many thoughts");


            try{
Thread.sleep(3000);
            }catch(Exception e){

            }
            sup_txt3.setText("I am sensing the letter A");

        }
    };

Answer 1

我将postDelayed()用于此类任务

sup_txt3.postDelayed(() -> sup_txt3.setText("I am sensing the letter A", 3000);

我做短了，完整的代码是

sup_txt3.postDelayed(new Runnable() {
   @Override
   public void run() {
      sup_txt3.setText("I am sensing the letter A");
   }
}, 3000);