我的验证不起作用 [英] my validation not working

问题描述

大家好

我正在研究需要验证用户输入的WPF应用程序。请帮我理解我错过的东西。以下是当前验证方案的示例：



PersonViewModel.cs：

  public   class  PersonViewModel：WorkspaceViewModel，IDataErrorInfo 
 {
 
 SDPS.Business.Base.BaseBusiness< Person> bz =  new  Business.Base.BaseBusiness< Person>（）; 
 
 
  public  PersonViewModel（ string  displayTitle）
 {
 Items = bz.GetAll（）; 
 DisplayName = displayTitle; 
 NewCommand =  new  RelayCommand（p = >  NewItem（））; 
 SaveCommand =  new  RelayCommand（p = >  SaveItem（），s => CanSave ）; 
 
} 
 
   #endregion 
  
  < span class =code-region>＃region Methods 
   private   void  NewItem（）
 {
 
 CurrentItem =  new  Person（）; 
 
 
} 
  私人 无效 SaveItem（）
 {
 
  if （ this  .Error = =  null ）
 {
 bz.Add（CurrentItem）; 
 Items.Add（CurrentItem）; 
} 
}  
   #region属性
  
  public  Person CurrentItem 
 {
  get  { return  _CurrentItem; } 
  set  
 {
 _CurrentItem =  value ; 
  if （ value ！=  null ）
 {
 _CurrentItem =  value ; 
} 
 OnPropertyChanged（  CurrentItem）; 
} 
} 
 
  public  ObservableCollection< Person>商品
 {
 获取 {返回 _items; } 
  set  
 {
 _items =  value ; 
 OnPropertyChanged（  Items）; 
} 
} 
 
   #region变量
  私人 ObservableCollection< Person> _items; 
  private  Person _CurrentItem; 
 
   #endregion 
  
  public   string 错误
 {
  get  { return   null ; } 
} 
 
  public   string   this  [ string  propertyName] 
 {
  get  
 {
  if （propertyName ==  名称）
 {
 
  if （CurrentItem.Name ==   0）
  return   错误......; 
} 
  return    ; 
} 
} 

XAML使用验证：

 <   TextBox    名称  =  txtName    
   
                                                                    高度  =  23    Horizo​​ntalAlignment   = 左   保证金  =  53,52,0,0      VerticalAlignment   =  Top   宽度  =  120        >  
 <   TextBox.Text  >  
 <  绑定   路径  =  CurrentItem.Name    
   
                                     ValidatesOnExceptions   =   True  
   
                                     UpdateSourceTrigger   =  PropertyChanged >  
 
 <   / Binding  >  
 <   / TextBox.Text  >  
 <   / TextBox  >  

解决方案

Hi guys
I'm working on a WPF app which needs to validate user input. Please help me understand what I am missing. Below is an example of the current Validation scenario:

PersonViewModel.cs:

 public class PersonViewModel : WorkspaceViewModel, IDataErrorInfo
    {

        SDPS.Business.Base.BaseBusiness<Person> bz = new Business.Base.BaseBusiness<Person>();

    
        public PersonViewModel(string displayTitle)
        {
            Items = bz.GetAll();
            DisplayName = displayTitle;
            NewCommand = new RelayCommand(p => NewItem());
            SaveCommand = new RelayCommand(p => SaveItem(),s=>CanSave);
     
        }

        #endregion

        #region Methods
        private void NewItem()
        {
 
            CurrentItem = new Person();


        }
         private void SaveItem()
        {
 
            if (this.Error == null)
            {
                bz.Add(CurrentItem);
                Items.Add(CurrentItem);
            }
        }
#region Properties

        public Person CurrentItem
        {
            get { return _CurrentItem; }
            set
            {
                _CurrentItem = value;
                if (value != null)
                {
                     _CurrentItem = value;
                }
                OnPropertyChanged("CurrentItem");
            }
        }
         
        public ObservableCollection<Person> Items
        {
            get { return _items; }
            set
            {
                _items = value;
                OnPropertyChanged("Items");
            }
        }

        #region Variables
        private ObservableCollection<Person> _items;
        private Person _CurrentItem;
         
        #endregion
 
        public string Error
        {
            get { return null; }
        }

        public string this[string propertyName]
        {
            get
            {
                if (propertyName == "Name")
                {

                    if  (CurrentItem.Name == "0")  
                        return "Error...";
                }
                return "";
            }
        }

XAML Usage Validation:

<TextBox Name="txtName" 

                                 Height="23" HorizontalAlignment="Left" Margin="56,42,0,0"  VerticalAlignment="Top" Width="120"   >
                            <TextBox.Text>
                            <Binding Path="CurrentItem.Name" 

                 ValidatesOnExceptions="True"

                 UpdateSourceTrigger="PropertyChanged">
                                     
                                </Binding>
                            </TextBox.Text>
                        </TextBox>

解决方案

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