Validation数据验证DataAnnotation机制和调试技巧

![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67c868925.jpg) 在学习了[Silverlight Validation数据验证基础属性和事件](http://www.cnblogs.com/jv9/archive/2010/09/09/1821891.html)后，大家对Silverlight数据验证应该有了一个简单明了的认识。今天，我将继续介绍另外一种Silverlight的Validation验证机制，DataAnnotation。在文章开始前，我想首先介绍一下Visual Studio中如何调试Silverlight的Validation代码。 Visual Studio 2010调试Silverlight Validation设置技巧* 相信大家在运行上一篇的代码时会发现，在异常出现时，Visual Studio会自动中断和获取当前异常错误信息，这为调试带来了一些不便。 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc33865.jpg) 针对以上问题，我们可以在Visual Studio中进行简单设置，暂时取消在Debug模式下对异常的捕获，方法如下：首先到Debug菜单，选择Exceptions菜单，也可以使用“Ctrl+Alt+E”，激活Exception窗口 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc42b33.jpg) ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc56021.jpg) 点击“Find”查找以下选项， System.Exception,将其后面的CheckBox取消选中， ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc6e9e4.jpg) 这样就实现了当数据验证时，Visual Studio不再捕获异常错误。对于本篇，我们将使用DataAnnotation验证机制，该验证机制与[上一篇](http://www.cnblogs.com/jv9/archive/2010/09/09/1821891.html)略有不同，所以，如果要实现Visual Studio忽略捕获异常，要另外在Exception窗口搜索“System.ComponentModel.DataAnnotations.ValidationException"，同样将其后面的CheckBox取消选中。 ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc7e667.jpg) Visual Studio 2008和Silverlight 3开发环境中，默认情况下Exception没有System.ComponentModel.DataAnnotations.ValidationException选项，开发人员可以自行添加一个新的异常即可，点击“Add”按钮， ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc8e569.jpg) 在完成以上的操作后，再次执行Silverlight应用调试Validation时，Visual Studio不再出现异常捕获，相对方便很多。 [Silverlight DataAnnotation](http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.aspx)验证机制 **验证Metadata属性** Silverlight的DataAnnotation验证机制是Silverlight 3发布WCF RIA Services测试版是推出的客户端验证机制，对于DataAnnotation的翻译，可以理解为“数据元素注释”验证法。该验证机制，使用了System.ComponentModel.DataAnnotations命名空间中的属性类，通过对DataMember数据成员设置Metadata元数据属性，对其验证值进行判断是否符合当前属性条件，以达到Validation的效果。该验证机制，多数运用于WCF RIA Services应用中. ~~~ private string _email; [Required(ErrorMessage = "必填选项")] public string email { get { return _email; } set { _email = value; } } ~~~ 从上面代码可以看到属性上面的注释 [Required(ErrorMessage = "必填选项")]，该注释就是DataAnnotations类中的固有属性，其结果是判断该控件内容是否为空，如果是，则弹出异常。目前常用的DataAnnotation属性如下列表： <table class="MsoTableGrid" style="border-collapse: collapse; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-yfti-tbllook: 1184; mso-padding-alt: 0cm 5.4pt 0cm 5.4pt;" border="1" cellspacing="0" cellpadding="0"><tbody><tr style="height: 29.55pt; mso-yfti-irow: 0; mso-yfti-firstrow: yes;"><td style="padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; border: black 1pt solid;" width="124"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">属性名称</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: black 1pt solid; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">描述</td></tr><tr style="height: 29.55pt; mso-yfti-irow: 1;"><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1;" width="124">Required</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; mso-border-bottom-themecolor: text1; mso-border-right-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">标识该属性为必需参数，不能为空</td></tr><tr style="height: 29.55pt; mso-yfti-irow: 2;"><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1;" width="124">StringLength</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; mso-border-bottom-themecolor: text1; mso-border-right-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">标识该字符串有长度限制，可以限制最小或最大长度</td></tr><tr style="height: 29.55pt; mso-yfti-irow: 3;"><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1;" width="124">Range</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; mso-border-bottom-themecolor: text1; mso-border-right-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">标识该属性值范围，通常被用在数值型和日期型</td></tr><tr style="height: 29.55pt; mso-yfti-irow: 4;"><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1;" width="124">RegularExpression</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; mso-border-bottom-themecolor: text1; mso-border-right-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">标识该属性将根据提供的正则表达式进行对比验证</td></tr><tr style="height: 29.55pt; mso-yfti-irow: 5; mso-yfti-lastrow: yes;"><td style="border-bottom: black 1pt solid; border-left: black 1pt solid; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 92.8pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1;" width="124">CustomValidation</td><td style="border-bottom: black 1pt solid; border-left: #f0f0f0; padding-bottom: 0cm; background-color: transparent; padding-left: 5.4pt; width: 244.7pt; padding-right: 5.4pt; height: 29.55pt; border-top: #f0f0f0; border-right: black 1pt solid; padding-top: 0cm; mso-border-alt: solid black .5pt; mso-border-themecolor: text1; mso-border-left-alt: solid black .5pt; mso-border-left-themecolor: text1; mso-border-top-alt: solid black .5pt; mso-border-top-themecolor: text1; mso-border-bottom-themecolor: text1; mso-border-right-themecolor: text1;" width="326"><span style="font-family: 宋体; mso-ascii-font-family: Calibri; mso-ascii-theme-font: minor-latin; mso-fareast-font-family: 宋体; mso-fareast-theme-font: minor-fareast; mso-hansi-font-family: Calibri; mso-hansi-theme-font: minor-latin;" lang="ZH-CN">标识该属性将按照用户提供的自定义验证方法，进行数值验证</td></tr></tbody></table> 在随后的实例中，我们将一一演示这些属性的使用方法。 **ValidationContext和Validator类** 阅读过上一篇Silverlight Validation基础的朋友应该知道，Silverlight的数据验证，可以在数据成员的Setter中设置条件验证，根据其验证结果判断是否符合验证。例如： ~~~ private int _age; public int Age { get { return _age; } set { if (value > 100 || value < 0) { throw new Exception("请输入年龄值在0 - 100之间."); } _age = value; } } ~~~ 在set中，判断年龄值是否超过100岁或者低于0岁，如果不符合条件，则抛出异常，该异常将被Validation机制捕获，并显示到UI。而Silverlight的DataAnnotation机制，与上面验证方法不同。Silverlight的DataAnnotation验证机制，在添加验证属性后，不需要在Setter中进行验证判断，仅需要在Setter中激活该验证属性即可，而要实现激活验证，则需要使用ValidationContext和Validator类。为了更好的理解Silverlight DataAnnotation验证机制，我们来对这两个类进行简单的讲解，首先说说[Validator类](http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.validator.aspx)，该类是一个静态类，主要用来当数据成员被指定验证元数据属性时，验证对象，属性和方法。简单的理解就是包含了各种具体验证方法的类。例如上文代码，我们使用了Require验证属性，Validator类将会根据该验证属性执行对应的验证方法，对目标值进行判断。在该类中，包含ValidateProperty方法和TryValidateProperty方法，可以分别对当前属性进行验证操作。而[ValiationContext类](http://msdn.microsoft.com/en-us/library/dd382177.aspx)，该类是对当前执行的数据验证提供上下文描述的。简单的理解，也就是为验证提供数据传输，属性标识等任务。我们对email属性，进行简单的修改，添加以上两个类，让该属性Silverlight的DataAnnotation机制生效。 ~~~ private string _email; [Required(ErrorMessage = "必填选项")] public string email { get { return _email; } set { var tmpValidator = new ValidationContext(this, null, null); tmpValidator.MemberName = "email"; Validator.ValidateProperty(value, tmpValidator); _email = value; } } ~~~ 在上文代码中，我们定义一个ValidationContext实例，该实例中包含了需要验证对象的引用，并且，我们定义了验证对象的MemberName，通过调用Validator.ValidateProperty静态方法，检查目标数据是否符合当前验证属性，如果返回False，则抛出一个ValidationException。上面代码也可简写为： ~~~ Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "email" }); ~~~ 当运行实例后，输入空格在邮件文本框中，Silverlight的DataAnnotation验证机制将被激活，生成如下效果： ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cc9dd9d.jpg) 在理解了上面的Silverlight的DataAnnotation验证机制的基本类和属性后，我们可以做几个简单的实例，来加深理解。 1. StringLength，定义Password密码框最大可输入6个字符， ~~~ <StackPanel Orientation="Horizontal" Margin="5"> <TextBlock Text="密码: " VerticalAlignment="Center"/> <TextBox x:Name="txtPassword" Width="200" DataContext="{Binding Source={StaticResource UserDataContext}}" Text="{Binding Path=password, Mode=TwoWay,ValidatesOnExceptions=True, NotifyOnValidationError=True}" /> </StackPanel> ~~~ ~~~ private string _password; [StringLength(6, ErrorMessage="密码不能超过6个字符")] public string password { get { return _password; } set { Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "password" }); _password = value; } } ~~~ ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67ccaef0b.jpg) 2. Range，我们使用Range属性设置Age年龄的有效范围， ~~~ <StackPanel Orientation="Horizontal" Margin="5"> <TextBlock Text="年龄: " VerticalAlignment="Center"/> <TextBox x:Name="txtAge" Width="200" DataContext="{Binding Source={StaticResource UserDataContext}}" Text="{Binding Path=Age, Mode=TwoWay, NotifyOnValidationError=True, ValidatesOnExceptions=True}" /> </StackPanel> ~~~ ~~~ private int _age; [Range(0, 100, ErrorMessage = "请输入年龄值在0 - 100之间")] public int Age { get { return _age; } set { Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "Age" }); _age = value; } } ~~~ ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67ccc484a.jpg) 3. RegularExpression，我们使用正则表达式属性，验证邮件输入框。 ~~~ <StackPanel Orientation="Horizontal" Margin="5"> <TextBlock Text="邮件: " VerticalAlignment="Center"/> <TextBox x:Name="txtEmail" Width="200" DataContext="{Binding Source={StaticResource UserDataContext}}" Text="{Binding Path=email, Mode=TwoWay, ValidatesOnNotifyDataErrors=False, NotifyOnValidationError=True, ValidatesOnExceptions=True}" /> </StackPanel> ~~~ ~~~ private string _email; [Required(ErrorMessage = "必填选项")] [RegularExpression(@"^([0-9a-zA-Z]([-./w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-/w]*[0-9a-zA-Z]/.)+[a-zA-Z]{2,9})$",ErrorMessage="请输入正确的Email格式")] public string email { get { return _email; } set { var tmpValidator = new ValidationContext(this, null, null); tmpValidator.MemberName = "email"; Validator.ValidateProperty(value, tmpValidator); _email = value; } } ~~~ ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67ccd38a6.jpg) 4. 自定义验证方法的应用我们创建一个简单的自定义验证方法，验证用户名是否为jv9. 首先创建自定义验证类，CustomizeValidation，在类中添加引用，using System.ComponentModel.DataAnnotations; 然后继承ValidationAttribute类，使其预定义该类为自定义验证属性，完成上面的设置后，即可创建自定义验证方法。 ~~~ public class CustomizeValidation : ValidationAttribute { protected override ValidationResult IsValid(object value, ValidationContext validationContext) { String checkName = value.ToString(); return checkName == "jv9" ? ValidationResult.Success : new ValidationResult("请使用指定用户名"); } } ~~~ 在Name属性中，进行调用， ~~~ private string _name; [CustomizeValidation] public string Name { get { return _name; } set { Validator.ValidateProperty(value, new ValidationContext(this, null, null) { MemberName = "Name" }); if (string.IsNullOrEmpty(value)) { throw new Exception("用户名不能为空."); } _name = value; } } ~~~ ![](https://docs.gechiui.com/gc-content/uploads/sites/kancloud/2016-03-18_56eb67cce6577.jpg) 对于Silverlight的DataAnnotation验证机制，相比其他验证机制使用起来较为简单，但是其本身具有一定局限性。特别是当数据成员来自服务器端，会因为类库无法共享使用造成无法正常验证。前文曾提及，该验证机制多数用在WCF RIA Services，因为WCF RIA应用提供的数据层，可生成对应客户端代码，即可实现在客户端的DataAnnotation验证。在随后的实例中，我将演示一套WCF RIA服务下的验证实例。今天讲到这里，希望大家能够有所收获。 [源代码下载](http://files.cnblogs.com/jv9/SilverlightValidationDemo.rar) 欢迎大家加入"专注Silverlight" 技术讨论群： 32679955(六群) 23413513(五群) 32679922(四群) 100844510(三群) 37891947(二群) 22308706(一群)