目前我正在使用mvvm的数据绑定来设置xml中的错误

public final ObservableField<String> errorViewEmail = new 
ObservableField<>();

和验证集错误:

errorViewEmail.set("error in view");

和xml代码:

<android.support.design.widget.TextInputLayout
                    android:id="@+id/emailEtLayout"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:textColorHint="@color/gray"
                    app:errorEnabled="true"
                    app:error="@{viewModel.errorViewEmail}"
                                                                                        app:errorTextAppearance="@style/error_appearance"


  app:hintTextAppearance="@style/TextAppearence.App.TextInputLayout">



                    <android.support.design.widget.TextInputEditText
                        android:id="@+id/etEmail"
                        style="@style/EditTextStyle"
                        android:layout_width="match_parent"
                        android:layout_height="wrap_content"
                        android:cursorVisible="true"
                        android:hint="@string/email"
                        android:inputType="textEmailAddress"
                        android:maxLength="50"
                        android:textSize="@dimen/_18sp" />
                </android.support.design.widget.TextInputLayout>

现在当我设置错误然后错误设置只有一次之后,我再次设置它什么都不做 . 我怎么能用它来验证电子邮件地址?或_11261_是否可能