這是我的MainPage.xaml中: -的PropertyChanged總是空
<UserControl x:Class="SilverlightPlainWCF.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="450" d:DesignWidth="800" xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk" xmlns:my="clr-namespace:SilverlightPlainWCF.CustomersServiceRef" Loaded="UserControl_Loaded">
<UserControl.Resources>
<CollectionViewSource x:Key="customerViewSource" d:DesignSource="{d:DesignInstance my:Customer, CreateList=True}" />
</UserControl.Resources>
<Grid x:Name="LayoutRoot" Background="White">
<sdk:DataGrid AutoGenerateColumns="False" Height="426" HorizontalAlignment="Left" ItemsSource="{Binding}" Margin="12,12,0,0" Name="customerDataGrid" RowDetailsVisibilityMode="VisibleWhenSelected" VerticalAlignment="Top" Width="776">
<sdk:DataGrid.Columns>
<sdk:DataGridTextColumn x:Name="addressColumn" Binding="{Binding Path=Address}" Header="Address" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="cityColumn" Binding="{Binding Path=City}" Header="City" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="companyNameColumn" Binding="{Binding Path=CompanyName}" Header="Company Name" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="contactNameColumn" Binding="{Binding Path=ContactName}" Header="Contact Name" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="contactTitleColumn" Binding="{Binding Path=ContactTitle}" Header="Contact Title" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="countryColumn" Binding="{Binding Path=Country}" Header="Country" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="customerIDColumn" Binding="{Binding Path=CustomerID}" Header="Customer ID" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="faxColumn" Binding="{Binding Path=Fax}" Header="Fax" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="phoneColumn" Binding="{Binding Path=Phone}" Header="Phone" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="postalCodeColumn" Binding="{Binding Path=PostalCode}" Header="Postal Code" Width="SizeToHeader" />
<sdk:DataGridTextColumn x:Name="regionColumn" Binding="{Binding Path=Region}" Header="Region" Width="SizeToHeader" />
</sdk:DataGrid.Columns>
</sdk:DataGrid>
</Grid>
</UserControl>
這是我的MainPage.xaml.cs中: -
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using SilverlightPlainWCF.CustomersServiceRef;
using System.Diagnostics;
using System.Collections.ObjectModel;
using System.ComponentModel;
namespace SilverlightPlainWCF
{
public partial class MainPage : UserControl, INotifyPropertyChanged
{
public MainPage()
{
InitializeComponent();
this.DataContext = Customers;
this.Loaded += new RoutedEventHandler(MainPage_Loaded);
}
public ObservableCollection<Customer> customers;
public ObservableCollection<Customer> Customers
{
get { return customers; }
set
{
customers = value;
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs("Customers"));
}
}
}
void MainPage_Loaded(object sender, RoutedEventArgs e)
{
CustomersServiceClient objCustomersServiceClient = new CustomersServiceClient();
objCustomersServiceClient.GetAllCustomersCompleted += (s, res) =>
{
if (res.Error == null)
{
Customers = new ObservableCollection<Customer>(res.Result);
}
else
{
MessageBox.Show(res.Error.Message);
}
};
objCustomersServiceClient.GetAllCustomersAsync();
}
private void UserControl_Loaded(object sender, RoutedEventArgs e)
{
// Do not load your data at design time.
// if (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(this))
// {
// //Load your data here and assign the result to the CollectionViewSource.
// System.Windows.Data.CollectionViewSource myCollectionViewSource = (System.Windows.Data.CollectionViewSource)this.Resources["Resource Key for CollectionViewSource"];
// myCollectionViewSource.Source = your data
// }
// Do not load your data at design time.
// if (!System.ComponentModel.DesignerProperties.GetIsInDesignMode(this))
// {
// //Load your data here and assign the result to the CollectionViewSource.
// System.Windows.Data.CollectionViewSource myCollectionViewSource = (System.Windows.Data.CollectionViewSource)this.Resources["Resource Key for CollectionViewSource"];
// myCollectionViewSource.Source = your data
// }
}
public event PropertyChangedEventHandler PropertyChanged;
}
}
,如果我只是招行: -
this.DataContext = Customers;
從構造函數到這裏: -
if (res.Error == null)
{
Customers = new ObservableCollection<Customer>(res.Result);
this.DataContext = Customers;
}
它工作正常,我得到的所有數據。可能是什麼問題。有誰能夠幫助我?
- 一旦ObservableCollection的內容發生變化,我就使用'INotifyPropertyChanged'來更新網格。我通過設置'this.DataContext = this'而不是'this.DataContext = Customers'並根據更改的DataGrid綁定到'{Binding Path = Customers}'而不是'{Binding}''來解決錯誤。 – TCM 2010-10-09 06:25:13
@Nitesh:當ObservableCollection的內容改變時,你不需要實現'INotifyPropertyChanged'來更新網格,這是ObservableCollection自身自動完成的。你實現'INotifyPropertyChanged'讓網格知道你指定了一個全新的'ObservableCollection'實例。是的,你也可以設置'this.DataContext = this',這是另一種方式。如果你明白爲什麼它的工作方式會更好,那會更好。 – Amry 2010-10-09 15:08:58
- 感謝您的親切。現在我的概念越來越清晰。但是有更多的疑問。我希望你不要介意回答他們。 1)當我們從UI(數據網格)添加新行時,該行會被添加到代碼的'ObservableCollection'後面嗎? 2)我應該做一個'DependencyProperty'或實現'INotifyPropertyChanged'?最佳做法是什麼?是不是'INotifyPropertyChanged'更有效? – TCM 2010-10-10 03:37:10