Prism 异步验证的示例。鉴于之前已经询问过 Prism 的多项功能包括异步验证我将提供一个精简且聚焦的回答基于 WPF 环境避免重复之前的内容如INotifyDataErrorInfo和模拟 API 的异步验证示例。本次示例将展示一个不同场景的异步验证例如验证密码强度通过异步 API 调用包括代码、测试代码、适用场景和使用方法。如果您有特定需求如与导航/区域的集成、更复杂的验证逻辑或特定测试场景请进一步说明我会定制答案。一、异步验证概述Prism 通过 WPF 的INotifyDataErrorInfo接口支持异步验证结合BindableBase和异步方法async/await实现动态输入验证。异步验证适用于需要远程或复杂逻辑的场景如 API 调用检查密码强度并通过错误通知机制更新 UI。主要特性异步处理支持耗时验证如 API 调用。错误通知通过INotifyDataErrorInfo提供动态错误反馈。MVVM 集成与 Prism 的 MVVM 模式无缝结合。模块化支持验证逻辑可定义在模块中。二、适用场景异步验证适用于远程验证如通过 API 检查密码强度或唯一性。复杂规则如验证密码是否符合安全策略长度、字符类型。实时反馈输入时异步验证并显示错误或状态。模块化应用模块中的视图模型需要独立异步验证。表单提交确保提交前所有字段通过异步验证。三、异步验证示例以下是一个异步验证密码强度的示例假设通过 API 检查密码是否满足要求。1. 项目配置安装 Prism NuGet 包如Prism.DryIoc。创建 Prism 应用程序继承PrismApplication.确保视图模型继承BindableBase。2. 定义模拟 API 服务模拟异步 API 调用以验证密码强度IPasswordValidationService.csusingSystem.Threading.Tasks;namespaceWpfApp.Services{publicinterfaceIPasswordValidationService{Task(boolIsValid,stringMessage)ValidatePasswordAsync(stringpassword);}}PasswordValidationService.csusingSystem.Text.RegularExpressions;usingSystem.Threading.Tasks;namespaceWpfApp.Services{publicclassPasswordValidationService:IPasswordValidationService{publicasyncTask(boolIsValid,stringMessage)ValidatePasswordAsync(stringpassword){// 模拟 API 延迟awaitTask.Delay(1000);if(string.IsNullOrEmpty(password))return(false,Password cannot be empty.);if(password.Length8)return(false,Password must be at least 8 characters.);if(!Regex.IsMatch(password,[A-Z]))return(false,Password must contain at least one uppercase letter.);if(!Regex.IsMatch(password,[0-9]))return(false,Password must contain at least one number.);return(true,Password is strong.);}}}3. 定义视图模型实现INotifyDataErrorInfo和异步验证逻辑MainWindowViewModel.csusingPrism.Commands;usingPrism.Mvvm;usingSystem.Collections;usingSystem.Collections.Generic;usingSystem.ComponentModel;usingSystem.Linq;usingSystem.Threading.Tasks;usingWpfApp.Services;namespaceWpfApp.ViewModels{publicclassMainWindowViewModel:BindableBase,INotifyDataErrorInfo{privatereadonlyIPasswordValidationService_validationService;privatestring_password;privatebool_isValidating;privatestring_validationMessage;privatereadonlyDictionarystring,Liststring_errorsnewDictionarystring,Liststring();publicstringPassword{get_password;set{if(SetProperty(ref_password,value)){ValidatePasswordAsync();}}}publicboolIsValidating{get_isValidating;setSetProperty(ref_isValidating,value);}publicstringValidationMessage{get_validationMessage;setSetProperty(ref_validationMessage,value);}publicDelegateCommandSubmitCommand{get;}publicMainWindowViewModel(IPasswordValidationServicevalidationService){_validationServicevalidationService;SubmitCommandnewDelegateCommand(OnSubmit,CanSubmit);}privateasyncvoidValidatePasswordAsync(){_errors.Remove(nameof(Password));IsValidatingtrue;ValidationMessageValidating...;try{var(isValid,message)await_validationService.ValidatePasswordAsync(_password);if(!isValid)AddError(nameof(Password),message);ValidationMessagemessage;}finally{IsValidatingfalse;RaiseErrorsChanged(nameof(Password));SubmitCommand.RaiseCanExecuteChanged();}}privatevoidOnSubmit(){ValidationMessageForm submitted successfully!;}privateboolCanSubmit(){return!HasErrors!IsValidating;}privatevoidAddError(stringpropertyName,stringerror){if(!_errors.ContainsKey(propertyName))_errors[propertyName]newListstring();_errors[propertyName].Add(error);}privatevoidRaiseErrorsChanged(stringpropertyName){ErrorsChanged?.Invoke(this,newDataErrorsChangedEventArgs(propertyName));}publicboolHasErrors_errors.Any();publiceventEventHandlerDataErrorsChangedEventArgsErrorsChanged;publicIEnumerableGetErrors(stringpropertyName){return_errors.ContainsKey(propertyName)?_errors[propertyName]:null;}}}4. 定义视图在MainWindow.xaml中应用异步验证并显示状态Window x:ClassWpfApp.MainWindow xmlnshttp://schemas.microsoft.com/winfx/2006/xaml/presentation xmlns:xhttp://schemas.microsoft.com/winfx/2006/xaml xmlns:localclr-namespace:WpfApp.Converters TitleMainWindow Height450 Width800 Window.Resources local:ErrorConverter x:KeyErrorConverter/ local:BooleanToVisibilityConverter x:KeyBoolToVisibilityConverter/ Style TargetTypeTextBox Style.Triggers Trigger PropertyValidation.HasError ValueTrue Setter PropertyToolTip Value{Binding RelativeSource{RelativeSource Self}, Path(Validation.Errors)[0].ErrorContent}/ Setter PropertyBorderBrush ValueRed/ /Trigger /Style /Style /Window.Resources Grid StackPanel Margin10 TextBox Width200 Margin5 TextBox.Text Binding PathPassword UpdateSourceTriggerPropertyChanged ValidatesOnNotifyDataErrorsTrue/ /TextBox.Text TextBox.ToolTip Binding Path(Validation.Errors) RelativeSource{RelativeSource Self} Converter{StaticResource ErrorConverter}/ /TextBox.ToolTip /TextBox TextBlock Text{Binding ValidationMessage} FontSize14 Margin5/ TextBlock TextValidating... Visibility{Binding IsValidating, Converter{StaticResource BoolToVisibilityConverter}} Margin5/ Button ContentSubmit Command{Binding SubmitCommand} Width100 Margin5/ /StackPanel /Grid /WindowErrorConverter.csusingSystem;usingSystem.Globalization;usingSystem.Windows.Controls;usingSystem.Windows.Data;namespaceWpfApp.Converters{publicclassErrorConverter:IValueConverter{publicobjectConvert(objectvalue,TypetargetType,objectparameter,CultureInfoculture){if(valueisReadOnlyObservableCollectionValidationErrorerrorserrors.Any())returnstring.Join(\n,errors.Select(ee.ErrorContent));returnnull;}publicobjectConvertBack(objectvalue,TypetargetType,objectparameter,CultureInfoculture){thrownewNotImplementedException();}}}BooleanToVisibilityConverter.csusingSystem;usingSystem.Globalization;usingSystem.Windows;usingSystem.Windows.Data;namespaceWpfApp.Converters{publicclassBooleanToVisibilityConverter:IValueConverter{publicobjectConvert(objectvalue,TypetargetType,objectparameter,CultureInfoculture){return(valueisboolisVisibleisVisible)?Visibility.Visible:Visibility.Collapsed;}publicobjectConvertBack(objectvalue,TypetargetType,objectparameter,CultureInfoculture){returnvalueisVisibilityvisibilityvisibilityVisibility.Visible;}}}5. 配置应用程序在App.xaml.cs中注册服务usingPrism.Ioc;usingSystem.Windows;usingWpfApp.Services;namespaceWpfApp{publicpartialclassApp:PrismApplication{protectedoverrideWindowCreateShell(){returnContainer.ResolveMainWindow();}protectedoverridevoidRegisterTypes(IContainerRegistrycontainerRegistry){containerRegistry.RegisterIPasswordValidationService,PasswordValidationService();}}}四、测试代码以下是使用 MSTest 和 Moq 的单元测试示例测试异步验证逻辑1. 测试依赖安装 NuGet 包Microsoft.NET.Test.SdkMSTest.TestFrameworkMSTest.TestAdapterMoqPrism.DryIoc2. 测试代码测试 PasswordValidationServiceusingMicrosoft.VisualStudio.TestTools.UnitTesting;usingSystem.Threading.Tasks;usingWpfApp.Services;[TestClass]publicclassPasswordValidationServiceTests{privatePasswordValidationService_service;[TestInitialize]publicvoidSetup(){_servicenewPasswordValidationService();}[TestMethod]publicasyncTaskValidatePasswordAsync_ValidPassword_ReturnsValid(){var(isValid,message)await_service.ValidatePasswordAsync(Password123);Assert.IsTrue(isValid);Assert.AreEqual(Password is strong.,message);}[TestMethod]publicasyncTaskValidatePasswordAsync_ShortPassword_ReturnsInvalid(){var(isValid,message)await_service.ValidatePasswordAsync(Pass123);Assert.IsFalse(isValid);Assert.AreEqual(Password must be at least 8 characters.,message);}[TestMethod]publicasyncTaskValidatePasswordAsync_NoUppercase_ReturnsInvalid(){var(isValid,message)await_service.ValidatePasswordAsync(password123);Assert.IsFalse(isValid);Assert.AreEqual(Password must contain at least one uppercase letter.,message);}}测试 MainWindowViewModelusingMicrosoft.VisualStudio.TestTools.UnitTesting;usingMoq;usingSystem.Linq;usingSystem.Threading.Tasks;usingWpfApp.Services;usingWpfApp.ViewModels;[TestClass]publicclassMainWindowViewModelTests{privateMockIPasswordValidationService_validationServiceMock;privateMainWindowViewModel_viewModel;[TestInitialize]publicvoidSetup(){_validationServiceMocknewMockIPasswordValidationService();_viewModelnewMainWindowViewModel(_validationServiceMock.Object);}[TestMethod]publicvoidPassword_Empty_AddsError(){_viewModel.Password;Assert.IsTrue(_viewModel.HasErrors);varerrors_viewModel.GetErrors(nameof(_viewModel.Password))asListstring;Assert.IsTrue(errors.Contains(Password cannot be empty.));}[TestMethod]publicasyncTaskPassword_Invalid_AddsError(){_validationServiceMock.Setup(ss.ValidatePasswordAsync(weak)).ReturnsAsync((false,Password must be at least 8 characters.));_viewModel.Passwordweak;awaitTask.Delay(1500);// 等待异步验证完成Assert.IsTrue(_viewModel.HasErrors);varerrors_viewModel.GetErrors(nameof(_viewModel.Password))asListstring;Assert.IsTrue(errors.Contains(Password must be at least 8 characters.));Assert.AreEqual(Password must be at least 8 characters.,_viewModel.ValidationMessage);}[TestMethod]publicasyncTaskPassword_Valid_NoErrors(){_validationServiceMock.Setup(ss.ValidatePasswordAsync(Password123)).ReturnsAsync((true,Password is strong.));_viewModel.PasswordPassword123;awaitTask.Delay(1500);// 等待异步验证完成Assert.IsFalse(_viewModel.HasErrors);Assert.AreEqual(Password is strong.,_viewModel.ValidationMessage);Assert.IsTrue(_viewModel.SubmitCommand.CanExecute(null));}[TestMethod]publicasyncTaskIsValidating_SetDuringValidation(){_validationServiceMock.Setup(ss.ValidatePasswordAsync(Password123)).ReturnsAsync((true,Password is strong.));boolisValidatingChangedfalse;_viewModel.PropertyChanged(s,e){if(e.PropertyNamenameof(_viewModel.IsValidating))isValidatingChangedtrue;};_viewModel.PasswordPassword123;awaitTask.Delay(1500);// 等待异步验证完成Assert.IsTrue(isValidatingChanged);Assert.IsFalse(_viewModel.IsValidating);}}3. 测试说明PasswordValidationService 测试验证有效密码返回正确结果。验证短密码和无大写字母的密码返回正确错误。MainWindowViewModel 测试验证空密码触发错误。验证无效密码触发异步错误。验证有效密码无错误且命令可执行。验证异步验证期间IsValidating属性变化。五、注意事项异步处理使用async void在属性设置中触发异步验证但需谨慎处理异常。考虑使用防抖debounce技术避免频繁触发异步调用。UI 反馈使用IsValidating和BooleanToVisibilityConverter显示验证进度。使用ErrorConverter显示错误消息。模块化集成异步验证逻辑可定义在模块中与区域或导航结合。性能优化避免短时间内多次触发异步验证。使用缓存或延迟机制优化 API 调用。测试注意使用Task.Delay模拟异步等待确保测试覆盖异步逻辑。使用 Moq 模拟异步服务。六、总结Prism 异步验证通过INotifyDataErrorInfo和async/await实现动态输入验证适合远程验证如密码强度检查和复杂业务规则。结合 Prism 的 MVVM 支持异步验证可集成到模块化应用中。上述代码示例展示了密码强度的异步验证测试代码验证了核心功能。如果您需要更具体的内容例如与区域/导航/事件聚合器的集成、其他异步验证场景或特定测试用例请提供细节我会进一步优化答案