WPF 验证之Attribute

效果

还是准备一个ViewModel  在要验证的属性上面添加验证特性

 1 public class ViewModel
 2     {
 3         private int _age;
 4 
 5         private string _eMail;
 6 
 7         private string _name;
 8 
 9         [Range(0, 120, ErrorMessage = "年龄范围[0-120]")]
10         public int Age
11         {
12             get => _age;
13             set { _age = value; ValidateProperty(value); }
14         }
15 
16         [EmailAddress(ErrorMessage = "邮箱地址不正确")]
17         public string Email
18         {
19             get { return _eMail; }
20             set { _eMail = value; ValidateProperty(value); }
21         }
22 
23         [Required(ErrorMessage = "姓名不能为空")]
24         [StringLength(12, MinimumLength = 4, ErrorMessage = "姓名长度[4-12]")]
25         public string Name
26         {
27             get => _name;
28             set { _name = value; ValidateProperty(value); }
29         }
30 
31         /// <summary>
32         /// 验证属性
33         /// </summary>
34         /// <typeparam name="T"></typeparam>
35         /// <param name="value"></param>
36         /// <param name="propertyName"></param>
37         protected void ValidateProperty<T>(T value, [CallerMemberName] string propertyName = "")
38         {
39             var contex = new ValidationContext(this) { MemberName = propertyName };
40             Validator.ValidateProperty(value, contex);//此处不好调试，要进入到异常，不知为何，有大佬指教吗？
41         }
42     }

前台界面

关键是 

ValidatesOnExceptions=True 这句代码，开启异常验证
 1 <Window.Resources>
 2         <ControlTemplate x:Key="TextBoxErrorTemplate">
 3             <StackPanel Orientation="Horizontal">
 4                 <AdornedElementPlaceholder x:Name="Adorner" />
 5                 <TextBlock
 6                     Margin="10,0,0,0"
 7                     Foreground="Red"
 8                     Text="{Binding ElementName=Adorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}" />
 9             </StackPanel>
10         </ControlTemplate>
11     </Window.Resources>
12     <Window.DataContext>
13         <local:ViewModel />
14     </Window.DataContext>
15     <Grid>
16         <StackPanel
17             Width="300"
18             HorizontalAlignment="Center"
19             VerticalAlignment="Center"
20             Orientation="Vertical">
21             <StackPanel Orientation="Horizontal">
22                 <TextBlock Text="姓名:" />
23                 <TextBox
24                     Width="220"
25                     Margin="5"
26                     Text="{Binding Path=Name, ValidatesOnExceptions=True}"
27                     Validation.ErrorTemplate="{StaticResource TextBoxErrorTemplate}" />
28             </StackPanel>
29             <StackPanel Orientation="Horizontal">
30                 <TextBlock Text="年龄:" />
31                 <TextBox
32                     Width="220"
33                     Margin="5"
34                     Text="{Binding Path=Age, ValidatesOnExceptions=True}"
35                     Validation.ErrorTemplate="{StaticResource TextBoxErrorTemplate}" />
36             </StackPanel>
37             <StackPanel Orientation="Horizontal">
38                 <TextBlock Text="邮箱:" />
39                 <TextBox
40                     Width="220"
41                     Margin="5"
42                     Text="{Binding Path=Email, ValidatesOnExceptions=True}"
43                     Validation.ErrorTemplate="{StaticResource TextBoxErrorTemplate}" />
44             </StackPanel>
45         </StackPanel>
46     </Grid>

可以看到，这种方法相对于IDataErrorInfo方便了很多 可以和ValidationRule配合使用

 

posted @ 2021-07-02 16:56  只吃肉不喝酒  阅读(357)  评论(0)    收藏  举报