Android EditText的设置错误提示信息

	    final EditText et = (EditText)findViewById(R.id.edit);

            et.setInputType(InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS);//只能输入邮箱地址

            if (et.getText().length() <= 0) {
                et.setHint("请输入邮箱地址");
            }

            final Drawable dr = getResources().getDrawable(R.drawable.ic_launcher);

            dr.setBounds(0, 0, 10, 10); //必须设置大小，否则不显示
            
            et.addTextChangedListener(new TextWatcher() { 
                
                public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                    
                } 
                public void onTextChanged(CharSequence s, int start, int before, int count) {
                    
                }
                @Override
                public void afterTextChanged(Editable arg0) {
                    // TODO Auto-generated method stub
                    if (et.getText().length() > 0) { //"[a-zA-Z0-9._-]+@[a-z]+.[a-z]+"

                        if (!et.getText().toString().matches("[a-zA-Z0-9._-]+@[a-z]+\\.+[a-z]+")) { 
                            et.setError("请输入正确的邮箱地址", dr);                  
                        }
                    } else {
                        et.setHint("请输入邮箱地址");
                    }
                } 
            });