如何使用INotifyPropertyChanged实现DataTable属性 [英] How to implement DataTable property with INotifyPropertyChanged

问题描述

我已经创建了WPF MVVM应用程序，并将WPFToolkit DataGrid绑定到DataTable，所以我想知道如何实现DataTable属性通知更改。目前我的代码如下所示。

  public DataTable Test 
 {
 get {return this.testTable; } 
 set 
 {
 ... 
 ... 
 base.OnPropertyChanged（Test）; 
} 
} 
 
 public void X（）
 {
 this.Test.Add（...）; //我想这行将首先调用getter（this.Test = get Test），然后它将调用add letter，这意味着setter范围将永远不会触发。 
 base.OnPropertyChanged（Test）; //我的解决方案在这里:)但我希望它有更好的方法。 
} 
  

是否有另一种解决方案？

解决方案

有两种方式可以更改表数据：可以从集合中添加/删除元素，或者元素中的某些属性可能会更改。

第一种情况很容易处理：使您的收藏品成为 ObservableCollection< T> 。在表上调用 .Add（T item）或 .Remove（item）将触发更改通知到查看为您（并且表将相应更新）

第二种情况是您需要您的T对象来实现INotifyPropertyChanged ...

最终您的代码应该如下所示：

  public class MyViewModel 
 {
 public ObservableCollection< MyObject> MyData {get;组; 
 
 
 public class MyObject：INotifyPropertyChanged 
 {
 public MyObject（）
 {
} 
 
私人字符串_status; 
 public string Status 
 {
 get {return _status; 
 set 
 {
 if（_status！= value）
 {
 _status = value; 
 RaisePropertyChanged（Status）; //传递更改的属性的名称
} 
} 
} 
 
 public event PropertyChangedEventHandler PropertyChanged; 
 
 private void RaisePropertyChanged（string propertyName）
 {
 PropertyChangedEventHandler handler = this.PropertyChanged; 
 if（handler！= null）
 {
 var e = new PropertyChangedEventArgs（propertyName）; 
处理程序（这个，e）; 
} 
} 
} 
  

现在设置你的查看为您的ViewModel的一个实例，并绑定到集合，如：

 < tk：DataGrid 
 ItemsSource ={Binding Path = MyData}
 ... /> 
  

希望这有帮助:)
Ian

I have created WPF MVVM application, and set WPFToolkit DataGrid binding to DataTable so I want to know how to implement DataTable property to notify changed. Currently my code is like below.

public DataTable Test
{
    get { return this.testTable; }
    set 
    { 
        ...
        ...
        base.OnPropertyChanged("Test");
    }
}

public void X()
{
    this.Test.Add(...); // I suppose this line will call to getter first (this.Test = get Test) and then it will call add letter, this mean that setter scope will never fire.
    base.OnPropertyChanged("Test"); // my solution is here :) but I hope it has better ways.
}

Is it has another solution for this problem?

解决方案

There are 2 ways your Table data could change: Either an element could be added/removed from the collection, or some properties from within an element could change.

The first scenario is easy to handle: make your collection an ObservableCollection<T>. Invoking .Add(T item) or .Remove(item) on your table will fire a change notification through to the View for you (and the table will update accordingly)

The second scenario is where you need your T object to implement INotifyPropertyChanged...

Ultimately your code should look something like this:

    public class MyViewModel
    {
       public ObservableCollection<MyObject> MyData { get; set; }
    }

    public class MyObject : INotifyPropertyChanged
    {
       public MyObject()
       {
       }

       private string _status;
       public string Status
       {
         get { return _status; }
         set
         {
           if (_status != value)
           {
             _status = value;
             RaisePropertyChanged("Status"); // Pass the name of the changed Property here
           }
         }
       }

       public event PropertyChangedEventHandler PropertyChanged;

       private void RaisePropertyChanged(string propertyName)
       {
          PropertyChangedEventHandler handler = this.PropertyChanged;
          if (handler != null)
          {
              var e = new PropertyChangedEventArgs(propertyName);
              handler(this, e);
          }
       }
    }

Now set the datacontext of your View to be an instance of your ViewModel, and bind to the collection, like:

<tk:DataGrid 
    ItemsSource="{Binding Path=MyData}"
    ... />

Hope this helps :) Ian

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