c#中使用数据验证器

前言

在很多情况下，用户的输入不一定满足我们的设计要求，需要验证输入是否正确，传统的方案是拿到控件数据进行逻辑判定验证后，给用户弹窗提示。这种方法有点职责延后的感觉，数据视图层应该很好的处理用户的输入。使用数据验证器，就可以友好的提示错误信息，让后端不用过多的验证数据正确性。

一、使用效果

二、实现代码

1、校验逻辑

 public class DataErrorInfoModel:NotifyBase{private string _userName;[Required(ErrorMessage ="用户名不能为空")][StringLength(100,MinimumLength =2,ErrorMessage ="最小长度为2")]public string UserName{get { return _userName; }set{_userName = value;this.Notify();}}private string _email;[Required(ErrorMessage = "邮箱不能为空")][StringLength(100, MinimumLength = 2, ErrorMessage = "最小长度为2")][RegularExpression("^[A-Za-z0-9\u4e00-\u9fa5]+@[a-zA-Z0-9_-]+(\\.[a-zA-Z0-9_-]+)+$",ErrorMessage = "请填写正确的邮箱地址！")]public string Email{get { return _email; }set{_email = value;this.Notify();}}}

 public class NotifyBase : INotifyPropertyChanged, IDataErrorInfo{public string this[string columnName]{get{var errors = new List<ValidationResult>();Validator.TryValidateProperty(this.GetType().GetProperty(columnName).GetValue(this, null),new ValidationContext(this){MemberName=columnName}, errors);if (errors.Count>0){return string.Join(Environment.NewLine, errors.Select(e => e.ErrorMessage).ToArray());}return "";}}public string Error => null ;public event PropertyChangedEventHandler PropertyChanged;public void Notify([CallerMemberName] string propName = ""){PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propName));}}

2、WPF前台

 <StackPanel Orientation="Horizontal" Grid.Row="2"><TextBox Width="200" Height="40" VerticalContentAlignment="Center" Margin="10"Template="{StaticResource ExceptionTextBoxTemplate}"Validation.ErrorTemplate="{StaticResource ExceptionTextBoxTemplate}"><TextBox.Text><Binding Path="DModel.UserName" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True"></Binding></TextBox.Text></TextBox><TextBox Width="200" Height="40" VerticalContentAlignment="Center" Margin="10"Template="{StaticResource ExceptionTextBoxTemplate}"Validation.ErrorTemplate="{StaticResource ExceptionTextBoxTemplate}"><TextBox.Text><Binding Path="DModel.Email" UpdateSourceTrigger="PropertyChanged" ValidatesOnDataErrors="True"></Binding></TextBox.Text></TextBox></StackPanel>

 <ControlTemplate x:Key="ExceptionTextBoxTemplate"><Border x:Name="border" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}"Background="{TemplateBinding Background}" SnapsToDevicePixels="True" CornerRadius="5"><Grid><ScrollViewer x:Name="PART_ContentHost" Focusable="false" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden" /><Border Width="16" Height="16" CornerRadius="8" Margin="5" Background="Red" VerticalAlignment="Center" HorizontalAlignment="Right" Visibility="Collapsed" Name="validation" ToolTip="{Binding (Validation.Errors)[0].ErrorContent,RelativeSource={RelativeSource AncestorType=TextBox, Mode=FindAncestor}}"><TextBlock Text="!" Foreground="White" VerticalAlignment="Center" HorizontalAlignment="Center" /></Border></Grid></Border><ControlTemplate.Triggers><Trigger Property="IsEnabled" Value="false"><Setter Property="Opacity" TargetName="border" Value="0.56" /></Trigger><Trigger Property="IsMouseOver" Value="true"><Setter Property="BorderBrush" TargetName="border" Value="{StaticResource TextBox.MouseOver.Border}" /></Trigger><Trigger Property="IsKeyboardFocused" Value="true"><Setter Property="BorderBrush" TargetName="border" Value="{StaticResource TextBox.Focus.Border}" /></Trigger><Trigger Property="Validation.HasError" Value="true"><Setter Property="BorderBrush" Value="Red" TargetName="border" /><Setter Property="Visibility" Value="Visible" TargetName="validation" /><Setter Property="ToolTip" Value="{Binding (Validation.Errors)[0].ErrorContent,RelativeSource={RelativeSource Self}}" /><!--<Setter Property="ToolTip" Value="{Binding RelativeSource={RelativeSource Self}, Path=(Validation.Errors)[0].ErrorContent}" />--></Trigger></ControlTemplate.Triggers></ControlTemplate>

3、控件关联（绑定数据源）

 this.DataContext = new DataErrorInfoViewModel();

三、FluentValidation扩展版本

1、校验逻辑

public class TemplateMatchParamValidator : AbstractValidator<TemplateMatchParam>{public TemplateMatchParamValidator(){/**   .NotNull()                属性不是 null*   .NotEmpty()               属性不是 null、空字符串或空格 (或值类型的默认值, 例如 int 0)。*   .NotEqual()               值不等于特定值 (或不等于其他属性的值)*   .Equal()                  值等于特定值 (或等于另一个属性的值)*   .Length()                 长度位于指定范围内。但是, 它不能确保字符串属性是否为 null。*   .MaxLength()              长度不超过指定的值*   .MinLength()              长度不能小于指定的值。*   .LessThan()               值小于特定值 (或小于另一个属性的值)*   .LessThanOrEqualTo()      值小于等于特定值 (或小于等于另一个属性的值)*   .GreaterThan()            值大于特定值 (或大于另一个属性的值)*   .GreaterThanOrEqualTo()   值大于等于特定值 (或大于等于另一个属性的值)*   .Must()                   值传递到一个委托中, 可以对该值执行自定义验证逻辑*   .Matches()                正则表达式验证*   .Email ()                 电子邮件验证**   .InclusiveBetween()      介于两者之间包括边界*   .ExclusiveBetween()      介于两者之间不包括边界**/RuleFor(vm => vm.Greed).NotNull().InclusiveBetween(0.01, 1).WithMessage($"请正确输入贪婪度:0.01-1");RuleFor(vm => vm.MaxOverlay).NotNull().InclusiveBetween(0.01, 1).WithMessage($"请正确输入最大重叠:0.01-1");RuleFor(vm => vm.MatchScore).NotNull().InclusiveBetween(0.1, 1).WithMessage($"请正确输入匹配分数:0.1-1");RuleFor(vm => vm.Threshold).NotNull().InclusiveBetween(10, 200).WithMessage($"请正确输入梯度阈值:10-200");RuleFor(vm => vm.MinLength).NotNull().InclusiveBetween(1, 100).WithMessage($"请正确输入最小长度:1-100");RuleFor(vm => vm.TimeOut).NotNull().InclusiveBetween(1, 10000).WithMessage($"请正确输入超时:1-10000");RuleFor(vm => vm.MinAngle).NotNull().InclusiveBetween(-180, 180).WithMessage($"请正确输入最小角度:-180-180");RuleFor(vm => vm.MaxAngle).NotNull().InclusiveBetween(-180, 180).WithMessage($"请正确输入最大角度:-180-180");RuleFor(vm => vm.MinRate).NotNull().InclusiveBetween(0.6, 1).WithMessage($"请正确输入最小比例:0.6-1");RuleFor(vm => vm.MaxRate).NotNull().InclusiveBetween(1, 1.5).WithMessage($"请正确输入最大比例:1-1.5");}}

    public class TemplateMatchParam : BindableBase, IDataErrorInfo{//其他代码省略// <summary>/// 当前属性设置错误信息，用于检验用户设置的参数是否正确/// </summary>public string Error{get{var results = validator.Validate(this);if (results != null && results.Errors.Any()){var distinctRes = results.Errors.GroupBy(x => x.PropertyName).Select(y => y.FirstOrDefault());var errors = string.Join(Environment.NewLine, distinctRes.Select(x => x.ErrorMessage).ToArray());return errors;}if (LearnImage == null || !LearnImage.IsInitialized()){return "模板没有学习！";}return string.Empty;}}public string this[string columnName]{get{if (validator == null){validator = new TemplateMatchParamValidator();}var firstOrDefault = validator.Validate(this).Errors.FirstOrDefault(lol => lol.PropertyName == columnName);return firstOrDefault?.ErrorMessage;}}private TemplateMatchParamValidator validator { get; set; }}

2、WPF前台

  <TextBoxGrid.Row="1"Grid.Column="1"Style="{StaticResource ParamSetHaveErrorTbStyle}"Text="{Binding TemplateMatchParam.Threshold, ValidatesOnDataErrors=True}" />