我被告知Christian Moser（http://wpftutorial.net/ValidationErrorByCode.html）的这段代码正在进行验证，只有源头发生变化，但我不知道在哪里放置它。我试过投入一个 'PreviewLostKeyboardFocus'类，但它不起作用。我已经有一个验证类，只有在文本框中有直接用户输入时才能使用，但我也希望通过其他文本框的计算进行验证。
我在ViewModel中也有属性：INotifyPropertyChanged，但我是MVVM的新手。所以我不熟悉IDataErrorInfo，如果可能的话宁愿使用INotifyPropertyChanged。
ValidationError validationError =
new ValidationError(regexValidationRule,
textBox.GetBindingExpression(TextBox.TextProperty));
validationError.ErrorContent = "This is not a valid e-mail address";
Validation.MarkInvalid(
textBox.GetBindingExpression(TextBox.TextProperty),
validationError);
我的财产
private int _FIMSamlet_score;
public int FIMSamlet_score
{
get { return this._FIMSamlet_score; }
set
{
if (Int32.Parse(value.ToString()) < 18 || Int32.Parse(value.ToString()) > 126)
{ throw new ArgumentException("The value must be between 18 and 126"); }
this._FIMSamlet_score = value;
this.OnPropertyChanged("FIMSamlet_score");
}
}
答案 0 :(得分：0)
IDataErrorInfo是使用INotifyPropertyChanged的验证方案的重要组成部分。当您在ValidateOnDataErrors=true上设置Binding时，在获取INotifyPropertyChanged启用的属性期间，会验证该值并设置该值。
您链接到的方法需要您在代码隐藏中放置广泛的业务逻辑，这违反了MVVM职责分离原则（哑视图，智能ViewModel）。
我强烈建议您了解IDataErrorInfo，更重要的是了解ValidationAttributes定义的System.ComponentModel.DataAnnotations，因为它们实际上是在纯MVVM环境中执行验证的最简单方法。
查看Microsoft提供的此代码示例，其中介绍了如何将这些注释与IDataErrorInfo集成到基础ViewModel类中，您可以继承该类并将其用作验证{{1 }} class：Validation in MVVM using Data Annotations
答案 1 :(得分：0)
ViewModel -> VMStudent.cs
using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;
using System.Windows;
using WpfDesktopCrud.Model;
namespace WpfDesktopCrud.ViewModel
{
class VMStudent : ViewModelBase, IDataErrorInfo
{
public VMStudent()
{
try
{
Students = new ObservableCollection<Student>();
Students.Add(new Student { id = 1, name = "Dhru", mobno = "0000000000", address = "Shahibaug", email = "dhrusoni84@gmail.com" });
Students.Add(new Student { id = 2, name = "Soni", mobno = "9033259059", address = "Vastrapur", email = "dhru_soni@yahoo.com" });
SaveCommand = new RelayCommand(Save);
NewCommand = new RelayCommand(New);
DeleteCommand = new RelayCommand(Delete);
PropertyChanged += VMStudent_PropertyChanged;
}
catch (Exception ex)
{
throw;
}
}
void VMStudent_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
switch (e.PropertyName)
{
case "Selected":
if (Selected != null)
{
ID = Selected.id;
Name = Selected.name;
MobileNo = Selected.mobno;
Address = Selected.address;
Email = Selected.email;
}
break;
}
}
#region Properties
private ObservableCollection<Student> _Students;
public ObservableCollection<Student> Students
{
get { return _Students; }
set
{
_Students = value;
RaisePropertyChanged("Students");
}
}
private Student _Selected;
public Student Selected
{
get { return _Selected; }
set
{
_Selected = value;
RaisePropertyChanged("Selected");
}
}
private int _ID;
public int ID
{
get { return _ID; }
set
{
_ID = value;
RaisePropertyChanged("ID");
}
}
private string _Name;
public string Name
{
get { return _Name; }
set
{
_Name = value;
RaisePropertyChanged("Name");
}
}
private string _MobileNo;
public string MobileNo
{
get { return _MobileNo; }
set
{
_MobileNo = value;
RaisePropertyChanged("MobileNo");
}
}
private string _Address;
public string Address
{
get { return _Address; }
set
{
_Address = value;
RaisePropertyChanged("Address");
}
}
private string _Email;
public string Email
{
get { return _Email; }
set
{
_Email = value;
RaisePropertyChanged("Email");
}
}
#endregion
#region Commands
public RelayCommand SaveCommand { get; set; }
public RelayCommand NewCommand { get; set; }
public RelayCommand DeleteCommand { get; set; }
#endregion
#region Methods
public void Save()
{
if (Selected != null)
{
if (Selected.id != 0)
{
Selected.name = this.Name;
Selected.mobno = this.MobileNo;
Selected.address = this.Address;
Selected.email = this.Email;
MessageBox.Show("Record Updated.", "WPF MVVM", MessageBoxButton.OK, MessageBoxImage.Information, MessageBoxResult.OK);
this.ID = 0;
this.Name = string.Empty;
this.Address = string.Empty;
this.MobileNo = string.Empty;
this.Email = string.Empty;
}
}
else
{
try
{
Students.Add(new Student { id = Students.Count + 1, name = this.Name, mobno = this.MobileNo, address = this.Address, email = this.Email });
MessageBox.Show("Record Saved.", "WPF MVVM", MessageBoxButton.OK, MessageBoxImage.Information, MessageBoxResult.OK);
this.ID = 0;
this.Name = string.Empty;
this.MobileNo = string.Empty;
this.Address = string.Empty;
this.Email = string.Empty;
}
catch (Exception ex)
{
throw;
}
}
}
public void New()
{
if (Selected != null)
{
this.ID = 0;
this.Name = string.Empty;
this.MobileNo = string.Empty;
this.Address = string.Empty;
this.Email = string.Empty;
Selected.id = 0;
}
Selected = null;
}
public void Delete()
{
try
{
Students.Remove(Selected);
this.Name = string.Empty;
this.MobileNo = string.Empty;
this.Address = string.Empty;
this.Email = string.Empty;
MessageBox.Show("Record Deleted.", "WPF MVVM", MessageBoxButton.OK, MessageBoxImage.Information, MessageBoxResult.OK);
}
catch (Exception ex)
{
throw;
}
}
#endregion
public string Error
{
get { throw new NotImplementedException(); }
}
public string this[string columnName]
{
get
{
string result = null;
if (columnName == "Name")
{
if (string.IsNullOrEmpty(Name))
{
result = "Name Cannot Be Empty";
return result;
}
string st = @"!|@|#|\$|%|\?|\>|\<|\*";
if (Regex.IsMatch(Name, st))
{
result = "special chatachter are not allowed";
return result;
}
}
if (columnName == "MobileNo")
{
if (string.IsNullOrEmpty(MobileNo))
{
result = "Mobile Can not be empty";
return result;
}
if (MobileNo.Length > 10 || MobileNo.Length < 10)
{
result = "number should be 10 charachters";
return result;
}
string s1 = @"^[0-9]*$";
if (!Regex.IsMatch(MobileNo, s1))
{
result = "Mobile number contain numeric value ";
return result;
}
else
{
return null;
}
}
if (columnName == "Address")
{
if (string.IsNullOrEmpty(Address))
{
result = "fill your address";
return result;
}
}
if (columnName == "Email")
{
string s1 = @"^[a-zA-Z][\w\.-]{2,28}[a-zA-Z0-9]@[a-zA-Z0-9][\w\.-]*[a-zA-Z0-9]\.[a-zA-Z][a-zA-Z\.]*[a-zA-Z]$";
if (string.IsNullOrEmpty(Email))
{
result = "Email can not be empty";
return result;
}
if (Regex.IsMatch(Email, s1)) //|| Regex.IsMatch(Email, s2))
{
return null;
}
else
{
result = "Not valid email(format: dhru@gmail.com)";
return result;
}
}
return null;
}
}
}
}
View - > Student.xaml
<Window x:Class="WpfDesktopCrud.View.Students"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:VM="clr-namespace:WpfDesktopCrud.ViewModel"
Title="Students" Height="400" Width="500">
<Window.DataContext>
<VM:VMStudent/>
</Window.DataContext>
<Grid>
<Grid.Resources>
<ControlTemplate x:Key="dTemplate">
<StackPanel Orientation="Horizontal">
<DockPanel LastChildFill="True">
<TextBlock DockPanel.Dock="Right" Text="{Binding AdornedElement.(Validation.Errors).[0].ErrorContent, ElementName=ErrorAdorner}" Background="#FA5858" Foreground="White" FontWeight="Light" VerticalAlignment="Center"/>
<AdornedElementPlaceholder VerticalAlignment="Top" x:Name="ErrorAdorner">
<Border BorderBrush="Red" BorderThickness="1" />
</AdornedElementPlaceholder>
</DockPanel>
</StackPanel>
</ControlTemplate>
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<ListBox ItemsSource="{Binding Students}" SelectedItem="{Binding Selected}" DisplayMemberPath="name" SelectedValuePath="id" Margin="0,0,0,26">
</ListBox>
<Grid Grid.Row="1" HorizontalAlignment="Center">
<Grid.Resources>
<Style TargetType="TextBlock">
<Setter Property="Margin" Value="5 2 5 0"/>
<Setter Property="HorizontalAlignment" Value="Right"/>
</Style>
<Style TargetType="TextBox">
<Setter Property="Margin" Value="5 5 5 5"/>
</Style>
</Grid.Resources>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
<ColumnDefinition Width="200"/>
</Grid.ColumnDefinitions>
<TextBlock Text="Name"/>
<TextBlock Text="Mobile No" Grid.Row="1"/>
<TextBlock Text="Address" Grid.Row="2"/>
<TextBlock Text="Email" Grid.Row="3"/>
<TextBox x:Name="txtName" Text="{Binding Name,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay,ValidatesOnDataErrors=True}" Validation.ErrorTemplate="{StaticResource dTemplate}"
Grid.Column="1"/>
<TextBox x:Name="txtNo" Text="{Binding MobileNo,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay,ValidatesOnDataErrors=True}" Validation.ErrorTemplate="{StaticResource dTemplate}"
Grid.Row="1" Grid.Column="1"/>
<TextBox x:Name="txtAdd" Text ="{Binding Address,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay,ValidatesOnDataErrors=True}" Validation.ErrorTemplate="{StaticResource dTemplate}"
Grid.Row="2" Grid.Column="1" TextWrapping="WrapWithOverflow" AcceptsReturn="True" ScrollViewer.CanContentScroll="True" VerticalScrollBarVisibility="Auto" Height="90"/>
<TextBox x:Name="txtEmail" Text ="{Binding Email,UpdateSourceTrigger=PropertyChanged,Mode=TwoWay,ValidatesOnDataErrors=True}" Validation.ErrorTemplate="{StaticResource dTemplate}"
Grid.Row="3" Grid.Column="1"/>
</Grid>
<WrapPanel Grid.Row="3" HorizontalAlignment="Center" >
<Button Command="{Binding NewCommand}" Content="New" Width="75" Height="31">
<Button.Style>
<Style TargetType="{x:Type Button}">
<EventSetter Event="Click" Handler="MoveFocusOnClick"/>
</Style>
</Button.Style>
</Button>
<Button Command="{Binding SaveCommand}" Content="Save" Width="75" Height="31">
<Button.Style>
<Style TargetType="Button">
<Setter Property="IsEnabled" Value="False"/>
<Style.Triggers>
<MultiDataTrigger>
<MultiDataTrigger.Conditions>
<Condition Binding ="{Binding Path=(Validation.HasError),ElementName=txtName}" Value="false"/>
<Condition Binding ="{Binding Path=(Validation.HasError),ElementName=txtNo}" Value="false"/>
<Condition Binding ="{Binding Path=(Validation.HasError),ElementName=txtAdd}" Value="false"/>
<Condition Binding ="{Binding Path=(Validation.HasError),ElementName=txtEmail}" Value="false"/>
</MultiDataTrigger.Conditions>
<Setter Property="IsEnabled" Value="True"/>
</MultiDataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
<Button Command="{Binding DeleteCommand}" Content="Delete" Width="75" Height="31"/>
</WrapPanel>
</Grid>
</Window>
Model -> Student.cs
using GalaSoft.MvvmLight;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace WpfDesktopCrud.Model
{
class Student : ViewModelBase
{
private int _id;
public int id
{
get { return _id; }
set
{
_id = value;
RaisePropertyChanged("id");
}
}
private string _name;
public string name
{
get { return _name; }
set
{
_name = value;
RaisePropertyChanged("name");
}
}
private string _mobno;
public string mobno
{
get { return _mobno; }
set
{
_mobno = value;
RaisePropertyChanged("mobno");
}
}
private string _address;
public string address
{
get { return _address; }
set
{
_address = value;
RaisePropertyChanged("address");
}
}
private string _email;
public string email
{
get { return _email; }
set
{
_email = value;
RaisePropertyChanged("email");
}
}
private DateTime _timer;
public DateTime Timer
{
get { return _timer; }
set
{
_timer = value;
RaisePropertyChanged("timer");
}
}
}
}