返回教程目录
在上一篇中，我们了解到怎样使用Linq to SQL+Silverlight-enabled WCF Web Service与DataGrid进行CURD操作。本教程将用另一种常用的数据通讯方式ADO.NET Entity Framework+ADO.NET Data Service来实现与DataGrid进行CURD操作的过程,大家可以比较一下，两者的服务端与客户端操作方式之间的差别。
准备工作
1）建立起测试项目
2）创建测试用数据库
细节详情请见强大的DataGrid组件[2]_数据交互。
创建ADO.NET Entity数据库实体模型
详情请见强大的DataGrid组件[2]_数据交互。
建立ADO.NET Data Service数据通讯服务
具体过程请见强大的DataGrid组件[2]_数据交互，这里不再赘述。
通过对比可以发现，ADO.NET Entity Framework+ADO.NET Data Service在服务端的配置相对于Linq to SQL+Silverlight-enabled WCF Web Service而言更为方便；而在客户端的配置方面则恰好相反，个人感觉ADO.NET Entity Framework+ADO.NET Data Service在操作方面较为复杂。
有关CURD过程的讲解在代码的注释部分中具体给出。
创建SilverlightClient界面及组件代码
MainPage.xaml文件代码：
<UserControl
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" xmlns:data="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data" x:Class="SilverlightClient.MainPage"
d:DesignWidth="320" d:DesignHeight="240">
<Grid x:Name="LayoutRoot" Background="White" Width="320" Height="240">
<data:DataGrid x:Name="dgEmployee" Margin="8,8,8,48" Background="#FFCEDBE8"/>
<Button x:Name="btnGetData" Height="30" HorizontalAlignment="Left" Margin="8,0,0,8" VerticalAlignment="Bottom" Width="64" Content="GetData"/>
<Button x:Name="btnInsert" Height="30" HorizontalAlignment="Left" Margin="88,0,0,8" VerticalAlignment="Bottom" Width="64" Content="Insert"/>
<Button x:Name="btnSave" Height="30" HorizontalAlignment="Right" Margin="0,0,88,8" VerticalAlignment="Bottom" Width="64" Content="Save"/>
<Button x:Name="btnDelete" Height="30" HorizontalAlignment="Right" Margin="0,0,8,8" VerticalAlignment="Bottom" Width="64" Content="Delete"/>
</Grid>
</UserControl>
MainPage.xaml.cs文件代码：
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 System.Data.Services.Client;//引入System.Data.Services.Client命名空间
using SilverlightClient.EmployeeServiceReference;//引入数据服务所在命名空间
namespace SilverlightClient
...{
public partial class MainPage : UserControl
...{
List BoundData = new List();//用于绑定的中间件
int rowCount = 0;//Employee表中数据个数
bool inEdit;//判断DataGrid是否处于编辑状态
EmployeesEntities proxy;//数据实体
public MainPage()
...{
InitializeComponent();
//注册事件触发处理
this.btnGetData.Click += new RoutedEventHandler(btnGetData_Click);
this.btnInsert.Click += new RoutedEventHandler(btnInsert_Click);
this.btnSave.Click += new RoutedEventHandler(btnSave_Click);
this.btnDelete.Click += new RoutedEventHandler(btnDelete_Click);
this.dgEmployee.CellEditEnded += new EventHandler(dgEmployee_CellEditEnded);
this.dgEmployee.BeginningEdit += new EventHandler(dgEmployee_BeginningEdit);
}
void dgEmployee_BeginningEdit(object sender, DataGridBeginningEditEventArgs e)
...{
inEdit = true;
}
void dgEmployee_CellEditEnded(object sender, DataGridCellEditEndedEventArgs e)
...{
inEdit = false;
try
...{
proxy.AttachTo("Employee", e.Row);//附着数据行
}
catch ...{ }
proxy.UpdateObject(e.Row.DataContext);//更新数据行
}
void btnDelete_Click(object sender, RoutedEventArgs e)
...{
if (dgEmployee.SelectedItem != null)//所选行非空
...{
try
...{
proxy.DeleteObject(dgEmployee.SelectedItem);//删除所选数据行
BoundData.Remove((Employee)dgEmployee.SelectedItem);//绑定中间件移除数据项
proxy.BeginSaveChanges(SaveChangesOptions.Batch, (asyncResult) =>
...{
try
...{
proxy.EndSaveChanges(asyncResult);
}
catch ...{ }
}, null);//异步操作
}
catch ...{ }
}
}
void btnSave_Click(object sender, RoutedEventArgs e)
...{
if (!inEdit)
...{
proxy.BeginSaveChanges(SaveChangesOptions.Batch, (asyncResult) =>
...{
try
...{
proxy.EndSaveChanges(asyncResult);
}
catch ...{ }
}, null);
}//异步操作
}
void btnInsert_Click(object sender, RoutedEventArgs e)
...{
Employee u = new Employee();
BoundData.Insert(rowCount, u);
dgEmployee.SelectedIndex = rowCount;
dgEmployee.BeginEdit();
proxy.AddObject("Employee", u);
}
void btnGetData_Click(object sender, RoutedEventArgs e)
...{
proxy = new EmployeesEntities(new Uri("EmployeeInfoService.svc", UriKind.Relative));
var query = from c in proxy.Employee select c;
DataServiceQuery userQuery = (DataServiceQuery)query;
userQuery.BeginExecute(new AsyncCallback(OnLoadComplete), query);//异步调用
}
void OnLoadComplete(IAsyncResult result)
...{
DataServiceQuery query = (DataServiceQuery)result.AsyncState;
BoundData = query.EndExecute(result).ToList();
dgEmployee.ItemsSource = BoundData;//将最终结果传给DataGrid
rowCount = BoundData.Count;
}
}
}
最终效果图：
