WPF开发随笔收录-DataAnnotations实现数据校验（MVVM架构下）
WPF开发随笔收录-DataAnnotations实现数据校验（MVVM架构下）
一、前言
在自己的项目中挺多地方需要涉及到数据验证的，初期的实现方式都是通过点击确定后再逐个验证数据是否符合要求，但这种方式会让后台代码变得很多很乱。于是就开始在网上需求好的解决方式，刚好看到了一个大佬的博客写了关于数据验证的博客，也成功将那个方法用在项目中了，今天就来这里分享一下。博客原文：https://www.cnblogs.com/wzh2010/p/6518834.html
二、正文
1、这里写一个简单的例子来作为参考，首先新建个项目，按照常规MVVM构建好项目，如下图。然后添加需要用到的通知基类和命令基类
2、然后就是添加一个验证的基类ValidateModelBase，后面需要实现验证的类直接继承这个类即可，这个代码是直接搬大佬的
public class ValidateModelBase : NotifyBase, IDataErrorInfo
{
public ValidateModelBase()
{
}
#region 属性
/// <summary>
/// 表当验证错误集合
/// </summary>
public Dictionary<string, string> dataErrors = new Dictionary<string, string>();
/// <summary>
/// 是否验证通过
/// </summary>
public bool IsValidated
{
get
{
if (dataErrors != null && dataErrors.Count > 0)
{
return false;
}
return true;
}
}
#endregion
public string this[string columnName]
{
get
{
ValidationContext vc = new ValidationContext(this, null, null);
vc.MemberName = columnName;
var res = new List<ValidationResult>();
var result = Validator.TryValidateProperty(this.GetType().GetProperty(columnName).GetValue(this, null), vc, res);
if (res.Count > 0)
{
string errorInfo = string.Join(Environment.NewLine, res.Select(r => r.ErrorMessage).ToArray());
AddDic(dataErrors, columnName, errorInfo);
return errorInfo;
}
RemoveDic(dataErrors, columnName);
return null;
}
}
public string Error
{
get
{
return null;
}
}
#region 附属方法
/// <summary>
/// 移除字典
/// </summary>
/// <param name="dics"></param>
/// <param name="dicKey"></param>
private void RemoveDic(Dictionary<string, string> dics, string dicKey)
{
dics.Remove(dicKey);
}
/// <summary>
/// 添加字典
/// </summary>
/// <param name="dics"></param>
/// <param name="dicKey"></param>
private void AddDic(Dictionary<string, string> dics, string dicKey, string dicValue)
{
if (!dics.ContainsKey(dicKey)) dics.Add(dicKey, dicValue);
}
#endregion
}
3、接着我们创建一个类，并添加需要验证的字段
public class UserModel : ValidateModelBase
{
private string userName;
[Required(ErrorMessage = "用户名不可为空")]
public string UserName
{
get { return userName; }
set { userName = value; DoNotify(); }
}
private string userAge;
[Required(ErrorMessage = "年龄不可为空")]
[Range(0, 100, ErrorMessage = "年龄范围为0~100")]
public string UserAge
{
get { return userAge; }
set { userAge = value; DoNotify(); }
}
private bool isFormValid;
public bool IsFormValid
{
get { return isFormValid; }
set { isFormValid = value; DoNotify(); }
}
}
4、重写一下TextBox的Validation.ErrorTemplate模板
<Style
x:Key="{x:Type TextBoxBase}"
BasedOn="{x:Null}"
TargetType="{x:Type TextBoxBase}">
<Setter Property="BorderThickness" Value="1" />
<Setter Property="Padding" Value="2,1,1,1" />
<Setter Property="AllowDrop" Value="true" />
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
<Setter Property="ScrollViewer.PanningMode" Value="VerticalFirst" />
<Setter Property="Stylus.IsFlicksEnabled" Value="False" />
<Setter Property="SelectionBrush" Value="{DynamicResource Accent}" />
<Setter Property="Validation.ErrorTemplate">
<Setter.Value>
<ControlTemplate>
<StackPanel Orientation="Vertical">
<Border
x:Name="adornerborder"
BorderThickness="1">
<Grid>
<AdornedElementPlaceholder x:Name="adorner" Margin="-1" />
</Grid>
</Border>
<Border
x:Name="errorBorder"
Background="Transparent"
CornerRadius="0"
IsHitTestVisible="False"
Opacity="0">
<TextBlock
VerticalAlignment="Center"
Foreground="Red"
Text="{Binding ElementName=adorner, Path=AdornedElement.(Validation.Errors)[0].ErrorContent}"/>
</Border>
</StackPanel>
<ControlTemplate.Triggers>
<DataTrigger Value="True">
<DataTrigger.Binding>
<Binding ElementName="adorner" Path="AdornedElement.Tag" />
</DataTrigger.Binding>
<DataTrigger.EnterActions>
<BeginStoryboard x:Name="fadeInStoryboard1">
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="errorBorder"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="00:00:00.15" />
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
<DataTrigger.Setters>
<Setter TargetName="adornerborder" Property="BorderBrush" Value="#FFdc000c" />
</DataTrigger.Setters>
</DataTrigger>
<DataTrigger Value="True">
<DataTrigger.Binding>
<Binding ElementName="adorner" Path="AdornedElement.IsKeyboardFocused" />
</DataTrigger.Binding>
<DataTrigger.EnterActions>
<BeginStoryboard x:Name="fadeInStoryboard">
<Storyboard>
<DoubleAnimation
Storyboard.TargetName="errorBorder"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="00:00:00.15" />
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
<DataTrigger.Setters>
<Setter TargetName="adornerborder" Property="BorderBrush" Value="#FFdc000c" />
</DataTrigger.Setters>
</DataTrigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
5、接着在主窗口添加两个TextBox，然后绑定上对应的字段，记得要加上这个ValidatesOnDataErrors=True，不然无效
<Grid>
<StackPanel HorizontalAlignment="Center" VerticalAlignment="Center">
<StackPanel Margin="0,10" Orientation="Horizontal">
<Label
Width="80"
Content="用户姓名：" />
<TextBox
Width="150"
Tag="{Binding UserModel.IsFormValid, UpdateSourceTrigger=PropertyChanged}"
Text="{Binding UserModel.UserName, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
</StackPanel>
<StackPanel Margin="0,10" Orientation="Horizontal">
<Label
Width="80"
Content="用户年龄：" />
<TextBox
Width="150"
Tag="{Binding UserModel.IsFormValid, UpdateSourceTrigger=PropertyChanged}"
Text="{Binding UserModel.UserAge, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
</StackPanel>
<Button
Margin="0,10,0,0"
Command="{Binding SubmitCommand}"
Content="提交" />
</StackPanel>
</Grid>
6、然后就是ViewModel的代码
public class MainWindowViewModel : NotifyBase
{
private UserModel userModel;
public UserModel UserModel
{
get { return userModel; }
set { userModel = value; DoNotify(); }
}
public CommandBase SubmitCommand { get; set; } = new CommandBase();
public MainWindowViewModel()
{
UserModel = new UserModel();
SubmitCommand.DoExecute = new Action<object>(DoSumit);
SubmitCommand.DoCanExecute = new Func<object, bool>((o) => { return true; });
}
private void DoSumit(object obj)
{
if (UserModel.IsValidated) MessageBox.Show("验证通过！");
else
{
UserModel.IsFormValid = true;
var dataErrors = UserModel.dataErrors;
MessageBox.Show("验证失败");
}
}
}
7、到这里功能的实现就基本完成了，不擅长讲解原理，不太懂得可以研究研究官方文档获取其他大佬的文章，实现效果如下：
漫思
