android Toast提示异常：java.lang.RuntimeException: Can't create handler inside thread that has not called

 android Toast提示异常：java.lang.RuntimeException: Can't create handler inside thread that has not called仔细检查了代码，不应该异常啊？？  没有 handler相关代码啊？原来是在子线程弹Toast了， 切记，Toast只能在UI线程弹出，如果一定要在子线程弹，那么就通过 new Handler(Looper.getMainLooper()) 来弹

private void toastTest() {      new Thread(new Runnable() {  @Override  public void run() {     Handler handler = new Handler(Looper.getMainLooper());    handler.post(new Runnable() {          @Override          public void run() {              //放在UI线程弹Toast              Toast.makeText(MainActivity.this, "toast in work thread", Toast.LENGTH_LONG).show();          }      });      //此处会发生异常              Toast.makeText(MainActivity.this, "toast in work thread", Toast.LENGTH_LONG).show();  }  ).start();   }