Android Studio 3.4.1 使用 FloatingActionButton

 implementation 'com.google.android.material:material:1.0.0-alpha3'

  FloatingActionButton fab_activity_main = findViewById(R.id.fab_activity_main);


        fab_activity_main.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
               // Toast.makeText(MainActivity.this,"删除成功",Toast.LENGTH_SHORT).show();
                Snackbar.make(view,"删除数据",Snackbar.LENGTH_SHORT).setAction("确定", new View.OnClickListener() {
                    @Override
                    public void onClick(View view) {
                                Toast.makeText(MainActivity.this,"删除成功",Toast.LENGTH_SHORT).show();
                    }
                }).show();
            }
        });