1.private void showToast(){
     Toast  toast = new Toast(this);
      ImageView imageview  = new ImageView(this);
      LinearLayout layout = new LinearLayout();
      layout.setOrientation(LinearLayout.HORIZONTAL);
      layout.addView(imageview);
      toast.setView(layout);
      toast.setDuration(Toast.LENGTH_LONG);
      toast.show();
}

2.private void showToast(){
      Toast toast  = new Toast(this);
      LayoutInflater inflater = getLayoutInflater();
      View layout = iniflater.inflate(R.layout.custom_toast,null);
      toast.setView(layout);
      toast.setDuration(Toast.LENGTH_LONG);
      toast.show();
}

3.避免内存泄露
 Toast.make(MainActivity.this,"Hello",Toast.LENGTH_LONG).show();

如果在toast消失之前，用户在前台进行返回操作，或者直接回到桌面，导致Activity无法被GC销毁，这个Activity
就引起了内存泄露，正确做法：

Toast.make(getApplicationContext(),"Hello",Toast.LENGTH_LONG).show();

getApplicationContext()是整个应用的上下文，不会持有Activity对象.