驗證規則與MVVM

Question

我有幾個驗證規則，我也使用MVVM。

我有一些「保存」按鈕，我想只在沒有任何datagridrows驗證我的規則時啓用。

如何，我應該在我的

 bool CanSaveChanges 
     { 
      get { return true; } 
     } 

的datagrid做的是綁定到集合public ICollectionView Customers

感謝您的幫助。

Answer 1

這裏添加新客戶屏幕的一個簡單的例子，我驗證的名稱和Tel.No，該按鈕將不會啓用，直到allPropertiesValid屬性設置爲true，這意味着所有的驗證，通過

查看

<Window FlowDirection="RightToLeft" x:Class="GlassStore.AddNewSpecialCustomer" 
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:local="clr-namespace:GlassStore.ViewModels" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    Title="AddNewSpecialCustomer" Height="346" Width="463" WindowStartupLocation="CenterScreen"> 

<Window.DataContext> 
    <local:AddNewSpecialCustomerViewModel/> 
</Window.DataContext> 
<Grid Background="{DynamicResource NormalBrush}"> 
    <Button IsDefault="True" Command="{Binding Save}" Content="موافق" Height="39" HorizontalAlignment="Left" Margin="15,256,0,0" VerticalAlignment="Top" Width="76" /> 
    <Label Content="إسم العميل" Height="36" HorizontalAlignment="Left" Margin="12,12,0,0" VerticalAlignment="Top" Width="79" /> 
    <TextBox Text="{Binding specialCustomerName,Mode=TwoWay,ValidatesOnDataErrors=True,ValidatesOnExceptions=True,UpdateSourceTrigger=PropertyChanged}" Height="36" HorizontalAlignment="Left" Margin="111,12,0,0" VerticalAlignment="Top" Width="209" /> 
    <Label Content="المنطقة/المكان" Height="35" HorizontalAlignment="Left" Margin="12,67,0,0" VerticalAlignment="Top" Width="94" /> 
    <TextBox Text="{Binding region}" Height="35" HorizontalAlignment="Left" Margin="111,67,0,0" VerticalAlignment="Top" Width="210" /> 
    <TextBox Text="{Binding tel,ValidatesOnDataErrors=True,ValidatesOnExceptions=True,UpdateSourceTrigger=PropertyChanged}" Height="33" HorizontalAlignment="Left" Margin="111,119,0,0" VerticalAlignment="Top" Width="210" /> 
    <Label Content="رقم الهاتف " Height="33" HorizontalAlignment="Left" Margin="12,119,0,0" VerticalAlignment="Top" Width="94" /> 
    <Button IsCancel="True" Content="إلغاء" Height="39" HorizontalAlignment="Left" Margin="128,256,0,0" VerticalAlignment="Top" Width="78" /> 
    <Label Content="{Binding errorMessage}" ToolTip="{Binding richMessage}" Foreground="{Binding messageColor}" Height="40" HorizontalAlignment="Left" Margin="12,182,0,0" VerticalAlignment="Top" Width="412" /> 
</Grid> 
</Window> 

視圖模型

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.ComponentModel; 
using System.Windows.Input; 
using System.Windows.Media; 
namespace GlassStore.ViewModels 
{ 
class AddNewSpecialCustomerViewModel:ViewModelBase,IDataErrorInfo 
{ 
    private String _errorMessage; 
    private Brush _messageColor; 
    private String _richMessage; 
    private String _specialCustomerName; 
    private String _region; 
    private String _tel; 
    private bool _allPropertiesValid; 
    private Dictionary<string, bool> validProperties; 
    private Commands.RelayCommand _save; 

    public AddNewSpecialCustomerViewModel() 
    { 

     validProperties = new Dictionary<string, bool>(); 
     validProperties.Add("specialCustomerName",false); 
     validProperties.Add("tel", false); 
     allPropertiesValid = false; 

    } 

    public String richMessage 
    { 

     get { return _richMessage; } 
     set 
     { 
      if (_richMessage != value) 
      { 
       _richMessage = value; 
       OnPropertyChanged("richMessage"); 
      } 
     } 
    } 
    public String errorMessage 
    { 

     get { return _errorMessage; } 
     set 
     { 
      if (_errorMessage != value) 
      { 
       _errorMessage = value; 
       OnPropertyChanged("errorMessage"); 
      } 
     } 
    } 

    public Brush messageColor 
    { 
     get 
     { 
      return _messageColor; 
     } 
     set 
     { 
      if (_messageColor != value) 
      { 
       _messageColor = value; 
       OnPropertyChanged("messageColor"); 
      } 

     } 
    } 

    public bool allPropertiesValid 
    { 

     get { return _allPropertiesValid; } 
     set 
     { 
      if (_allPropertiesValid != value) 
      { 
       _allPropertiesValid = value; 
       OnPropertyChanged("allPropertiesValid");     
      } 
     } 
    } 

    public String specialCustomerName 
    { 
     get { return _specialCustomerName; } 
     set 
     { 
      if (_specialCustomerName != value) 
      { 
       _specialCustomerName = value; 
       OnPropertyChanged("specialCustomerName"); 

      } 
     } 
    } 

    public ICommand Save 
    { 
     get 
     { 
      if (_save == null) 
      { 
       _save = new Commands.RelayCommand(param => CanAddSpecialCustomer(), param => AddSpecialCustomer()); 
      } 

      return _save; 
     } 
    } 



    public String region 
    { 
     get { return _region; } 
     set 
     { 
      if (_region != value) 
      { 
       _region = value; 
       OnPropertyChanged("region"); 

      } 
     } 
    } 

    public String tel 
    { 
     get { return _tel; } 
     set 
     { 
      if (_tel != value) 
      { 
       _tel = value; 
       OnPropertyChanged("tel"); 
      } 
     } 
    } 

    private bool CanAddSpecialCustomer() 
    { 
     return allPropertiesValid; 
    } 

    private void AddSpecialCustomer() 
    { 
     try 
     { 
      GlassStoreBLL.SpecialCustomer spcustomer = new GlassStoreBLL.SpecialCustomer(); 
      spcustomer.name = specialCustomerName; 
      spcustomer.region = region; 
      spcustomer.telNo = Int64.Parse(tel); 
      spcustomer.AddNewCustomer(spcustomer); 
      errorMessage = "نـجـاح"; 
      messageColor = Brushes.Green; 
      region = ""; 
      tel = ""; 
      specialCustomerName = ""; 
     } 
     catch (Exception d) 
     { 
      errorMessage = "خطأ أثناء تسجيل العميل الخاص"; 
      richMessage = d.Message; 
      messageColor = Brushes.Red; 
     } 
    } 


    string IDataErrorInfo.Error 
    { 
     get { return null; } 
    } 

    string IDataErrorInfo.this[string columnName] 
    { 
     get 
     { 
      string error = String.Empty; 
      switch (columnName) 
      { 
       case "specialCustomerName": 
        error = validateSpecialCustomerName(); 
        validProperties["specialCustomerName"] = String.IsNullOrEmpty(error) ? true : false; 
        validateProperties(); 
        return error; 
       case "tel": 
        error = validateTel(); 
        validProperties["tel"] = String.IsNullOrEmpty(error) ? true : false; 
        validateProperties(); 
        return error; 
       default: 
        throw new ApplicationException("Wrong Property name being validated"); 
      } 
     } 
    } 

    private string validateSpecialCustomerName() 
    { 
     if (String.IsNullOrEmpty(specialCustomerName)) 
     { 
      return "يجب إدخال إسم العميل الخاص"; 
     } 
     else 
     { 
      if (specialCustomerName.Length < 2) return "إسم العميل الخاص لا يمكن أن يكون حرفين"; 
     } 
     return String.Empty; 
    } 

    private string validateTel() 
    { 
     int result; 
     if (int.TryParse(tel, out result)) 
     { 
      if (tel.Count() < 6) 
      { 
       return "رقم التلفون لا يمكن أن يكون أقل من 6 أرقام"; 
      } 
      else 
      { 
       if (result < 0) 
       { 
        return "لا يمكن إدخال قيمة سالبة هنا"; 
       } 
       return String.Empty; 
      } 
     } 
     else 
     { 
      return "الرجاء إدخال أرقام فقط في رقم التلفون"; 
     } 

    } 

    private void validateProperties() 
    { 
     foreach (bool isValid in validProperties.Values) 
     { 
      if (isValid == false) 
      { 
       allPropertiesValid = false; 
       return; 
      } 
     } 
     allPropertiesValid = true; 
    } 
} 
}