MVVM数据绑定验证

时间:2020-05-14 18:28:20

标签: java android xml validation binding

我想验证使用MVVM和数据绑定的注册用户数据。这是我的代码,请指导我:

活动

    registerViewModel = new ViewModelProvider(this).get(RegisterViewModel.class);
    binding.setSignUpObject(new RegisterRequest());
    binding.setSignUpClickListener(registerViewModel);

模型

public class RegisterRequest extends BaseObservable {


@SerializedName("Email")
private String userEmail;
@SerializedName("Password")
private String userPassword;
@Expose
private String userConfirmPassword;
@SerializedName("Phone")
private String userPhone;
@SerializedName("ImagePath")
private String imagePath;
@SerializedName("Name")
private String userName;

@Expose
private RegisterErrors registerErrors;
}

//当然有带有nonotifyPropertyChanged的setter和带有@Bindable注释的getter //,然后创建一个RegisterErrors类以将其与app:error xml上的错误一起使用

RegisterErrors

public class RegisterErrors {

private String userEmailError;
private String userPasswordError;
private String userConfirmPasswordError;
private String userPhoneError;
private String imagePathError;
private String userNameError;

}

XML

   <variable
        name="signUpObject"
        type="com.rabe7.community.model.request.register.RegisterRequest" />

    <variable
        name="signUpClickListener"
        type="com.rabe7.community.view_model.user_management.RegisterViewModel" />

                        <com.google.android.material.textfield.TextInputLayout
                            android:layout_width="match_parent"
                            android:layout_height="wrap_content"
                            android:textColorHint="@color/colorBlackTransparent">

                            <EditText
                                android:id="@+id/et_sign_up_user_name"
                                android:layout_width="match_parent"
                                android:layout_height="match_parent"
                                android:layout_marginEnd="@dimen/dp16w"
                                android:hint="@string/label_sign_up_user_name"
                                app:error="@{signUpObject.registerErrors.userNameError}"
                                android:inputType="text"
                                android:maxLines="1"
                                android:text="@={signUpObject.userName}"
                                android:textColor="@color/colorBlack" />

                        </com.google.android.material.textfield.TextInputLayout>

问题是..我想在单击“提交”按钮后验证用户输入。.如何在具有绑定的视图模型上验证用户输入

我尝试:

viewModel

    public void onRegisterSubmitClicked(RegisterRequest registerRequest){
    this.registerRequest = registerRequest;

    if(registerRequest.getUserName().length()<6){
        registerRequest.getRegisterErrors().setUserNameError("error");
        }

}

但是app:error无效,我也不知道该怎么办..请帮助我,:)

1 个答案:

答案 0 :(得分:0)

您可以在ViewModel中这样做:

 /**
     * Two way bind-able fields
     */
    var userName: String = "" 

还要编写一种方法来验证ViewModel中的屏幕

fun validateSignupScreen() {
    if (userName.isEmpty()) {
        return
    } else if (userPassword.isEmpty()) {
        return
    } else {
        // Do your work here 
    }
}

在“活动”类中执行以下操作:

registerViewModel.validateSignupScreen()
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