Silverlight 3 - 如何"刷新"DataGrid内容？

Question

我有以下风景:

1    using System;
2    using System.Windows;
3    using System.Windows.Controls;
4    using System.Windows.Documents;
5    using System.Windows.Ink;
6    using System.Windows.Input;
7    using System.Windows.Media;
8    using System.Windows.Media.Animation;
9    using System.Windows.Shapes;
10   using System.Collections.Generic;
11   
12   namespace refresh
13   {
14      public partial class MainPage : UserControl
15      {
16          
17          List c = new List();
18   
19          public MainPage()
20          {
21              // Required to initialize variables
22              InitializeComponent();
23              c.Add(new Customer{ _nome = "Josimari", _idade = "29"});
24              c.Add(new Customer{_nome = "Wesley", _idade = "26"});
25              c.Add(new Customer{_nome = "Renato",_idade = "31"});    
26              
27              this.dtGrid.ItemsSource = c;
28          }
29   
30          private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
31          {
32              c.Add(new Customer{_nome = "Maiara",_idade = "18"});
33          }
34          
35      }
36      
37      public class Customer
38      {
39          public string _nome{get; set;}
40          public string _idade{get; set;}
41      }
42   }

哪里,dtGrid是我的DataGrid控件......

问题是:如何在我的列表中再添加一个寄存器后更新UI.

我得解决它将DataGrid的Item Source设置为"",然后再次设置为Customer对象列表,如下所示:

1    private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
2    
3    {
4    
5    c.Add(new Customer{_nome = "Maiara",_idade = "18"});
6    
7    this.dtGrid.ItemsSource="";
8    
9    this.dtGrid.ItemsSource=c;
10   
11   }
12   

有没有办法在更新,更改或删除列表c中的项目后更新UI或datagrid的itemsSource自动刷新？

谢谢,

Josimari Martarelli

Answer 1

我建议查看绑定,INotifyPropertyChanged,DataContexts和ObservableCollection.

1. 把你List变成一个ObservableCollection.仅这一点可能会解决你的一些问题...因为它ObservableCollection比一个简单的东西更强大List

2. 但是,如果你想解决更多这样的问题,你将考虑DataGrid通过Xaml将你的对象绑定到你的对象列表<DataGrid... ItemsSource="{Binding MyList}">

3. 为了绑定您DataGrid的List,您需要设置DataContext视图.这可以很简单,因为放置在构造函数中:this.DataContext = this; 设置DataContext告诉视图在查看Binding语句时查找数据的位置

4. 然后,为了解决你所拥有的问题(更改某些内容不会刷新视图),您将INotifyPropertyChanged在类上实现该接口.这将允许后面的代码向视图发送通知,以便在发生更改时通知它.

这是实现此目的的C#代码:

public partial class MainPage : UserControl, INotifyPropertyChanged
{
    private ObservableCollection<Customer> _MyList = 
        new ObservableCollection<Customer>();
    public ObservableCollection<Customer> MyList
    {
        get { return _MyList; }  
    } 

    public MainPage()
    {                      
        InitializeComponent();

        this.DataContext = this;

        MyList.Add(new Customer{ _nome = "Josimari", _idade = "29"});
        MyList.Add(new Customer{_nome = "Wesley", _idade = "26"});
        MyList.Add(new Customer{_nome = "Renato",_idade = "31"});

        OnPropertyChanged("MyList"); // This only works if you use bindings.
    }

    private void Button_Click(object sender, System.Windows.RoutedEventArgs e)
    {
        MyList.Add(new Customer{_nome = "Maiara",_idade = "18"});   

        OnPropertyChanged("MyList"); // This only works if you use bindings.
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged( string propertyName )
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    } 
}