Silverlight使用WCF RIA SERVICE实现CUD

这篇文章主要是使用WCF RIA SERVICE实现对数据的新增，更新，删除(CUD)。 

一：查看数据详情

接上面文章，我们已经实现了数据的列表展示，列表展示的数据的详细是有限的，所以需要做一个表单显示某个数据的详情。 
1.我们需要用到Silverlight Tookit，可以从http://silverlight.codeplex.com/下载。Silverlight tookit提供了很多有用的控件，这里我们用到了DataForm控件，这个控件在程序集System.Windows.Controls.Data.DataForm.Toolkit.dll。复制这个DLL到HRApp项目的Libs文件夹，如果没有新建。 
2.打开EmployeeList.xaml文件，增加如下声明

xmlns:dataForm="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.DataForm.Toolkit"

3.在EmployeeList页面的DataPager控件下面，加入下面的XAML。 

<dataForm:DataForm x:Name="dataForm1" Header="Employee Information" AutoGenerateFields="False" AutoEdit="False" AutoCommit="False" CurrentItem="{Binding SelectedItem, ElementName=dataGrid1}" Margin="0,12,0,0">
<dataForm:DataForm.EditTemplate>
<DataTemplate>
<StackPanel>
<dataForm:DataField Label="Employee ID">
<TextBox IsReadOnly="True"
Text="{Binding EmployeeID, Mode=OneWay}" />
</dataForm:DataField>
<dataForm:DataField Label="Login ID">
<TextBox Text="{Binding LoginID, Mode=TwoWay}" />
</dataForm:DataField>
<dataForm:DataField Label="Hire Date">
<TextBox Text="{Binding HireDate, Mode=TwoWay}" />
</dataForm:DataField>
<dataForm:DataField Label="Marital Status">
<TextBox Text="{Binding MaritalStatus, Mode=TwoWay}" />
</dataForm:DataField>
<dataForm:DataField Label="Gender">
<TextBox Text="{Binding Gender, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />
</dataForm:DataField>
<dataForm:DataField Label="Vacation Hours">
<TextBox Text="{Binding VacationHours, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />
</dataForm:DataField>
<dataForm:DataField Label="Sick Leave Hours">
<TextBox Text="{Binding SickLeaveHours, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />
</dataForm:DataField>
<dataForm:DataField Label="Active">
<CheckBox IsChecked="{Binding CurrentFlag, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />
</dataForm:DataField>
</StackPanel>
</DataTemplate>
</dataForm:DataForm.EditTemplate>
</dataForm:DataForm>

4.运行程序，进入EmployeeList页面，在列表中选择一项，dataform会显示该条数据的详情。 

二：更新数据

1.在新增Domain Service时 选中Enable Editing,选中后会自动生成CUD的方法。通过这些方法来更新数据。 
 
2.新增一个编辑按钮到EmployeeList页面。放置这个Button在DataForm控件后面。 

<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,12,0,0">
<Button x:Name="submitButton" Width="75" Height="23" Content="Submit" Margin="4,0,0,0" Click="submitButton_Click"/>
</StackPanel>

3.处理按钮的单击事件。 

private void submitButton_Click(object sender, RoutedEventArgs e)
{
employeeDataSource.SubmitChanges();
}

4.运行程序进入EmployeeList列表，你可以通过点击那个铅笔，这时DataForm处于编辑模式。对数据更改后，单击OK，结束编辑模式。单击Submit按钮保存数据。 
5.有时候需要更新某个字段，需要在Domain Service新增一个自定义的方法。打开OrganizationService.cs文件，加入下面的自定义的方法 

public void ApproveSabbatical(Employee current)
{
// Start custom workflow here
this.ObjectContext.Employees.AttachAsModified(current);
current.CurrentFlag = false;
}

6.编译项目，然后打开EmployeeList.xaml,新增按钮ApprovalSabbatical。 

 <StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,12,0,0">
<Button x:Name="submitButton" Width="75" Height="23" Content="Submit" Margin="4,0,0,0" Click="submitButton_Click"/>
<Button x:Name="approveSabbatical" Width="115" Height="23" Content="Approve Sabbatical" Margin="4,0,0,0" Click="approveSabbatical_Click"/>
</StackPanel>

 private void approveSabbatical_Click(object sender, RoutedEventArgs e)
{
Employee luckyEmployee = (Employee)(dataGrid1.SelectedItem);
luckyEmployee.ApproveSabbatical();
employeeDataSource.SubmitChanges();
}

8.运行程序。 

三：数据验证

DataForm控件有显示数据验证错误的功能，如验证Email格式不正确等。 
 
如何定义这些验证呢？在新增Domain Service Class的类的导航中，选中Generate associated classes for metadata。新增后会生成OrganizationService.metadata.cs，你可以在这里类中增加验证。 
 

打开这个类，为下面的两个属性增加验证的特性 

[Required]

public string Gender { get; set; }

[Range(0, 70)]

public short VacationHours { get; set; }

运行程序查看效果： 
 

四：自定义数据验证

.NET自带的数据验证是很有限的，这时我们需要自己定义我们需要的数据验证。 
1.在HRApp.Web项目新增 一个Code File,名字是OrganizationService.shared.cs。每当我们以.share.cs结尾命名的文件名，都会在Generated_Code生成。我们在这个文件加入下面的的代码： 

using System;

using System.ComponentModel.DataAnnotations;

namespace HRApp.Web

{

 public static class GenderValidator

 {

 public static ValidationResult IsGenderValid(string gender, ValidationContext context)

 {

 if (string.Compare(gender,"M", StringComparison.CurrentCultureIgnoreCase)==0 ||

 string.Compare(gender,"F",StringComparison.CurrentCultureIgnoreCase)==0)

 return ValidationResult.Success;

 else

 return new ValidationResult("The Gender field only has two valid values 'M'/'F'", new string[] { "Gender" });

 }

 }

}

打开OrganizationService.metadata.cs，在Gender属性加上上面的特性： 

[CustomValidation(typeof(HRApp.Web.GenderValidator), "IsGenderValid")]

[Required]

public string Gender { get; set; }

运行程序查看效果： 
  
还有一种自定义验证的方法是使用特性。数据验证的特性都是集成于ValidationAttribute的。通过重写IsValid方法来实现自定义验证。同样我们新增一个以shared.cs结尾的类文件。如下面代码实现如上面代码同样的功能： 

using System;

using System.ComponentModel.DataAnnotations;

namespace HRApp.Web

{

 public class GenderAttribute : ValidationAttribute

 {

 public GenderAttribute()

 {

 this.ErrorMessage = "The Gender field only has two valid values 'M'/'F'";

 }

 protected override ValidationResult IsValid(object value, ValidationContext validationContext)

 {

 if (value is string)

 {

 if (string.Compare(value.ToString(), "M", StringComparison.CurrentCultureIgnoreCase) == 0 ||

 string.Compare(value.ToString(), "F", StringComparison.CurrentCultureIgnoreCase) == 0)

 return ValidationResult.Success;

 else

 return new ValidationResult(ErrorMessage, new string[] { "Gender" });

 }

 else

 return new ValidationResult(ErrorMessage, new string[] { "Gender" });

 }

 }

}

五：新增

新增一个界面，用于录入员工信息。在HRApp项目，我们新增一个Silverlight Child Window 页面，名字是EmployeeRegistrationWindow.xaml。 
 
引用下面的命名空间 

using HRApp.Web;

增加下面的属性： 

public Employee NewEmployee { get; set; }

打开EmployeeRegistrationWindow.xaml文件，我们隐藏这个窗体的关闭按钮，需要为此窗体加入下面的属性： 

<controls:ChildWindow x:Class="HRApp.EmployeeRegistrationWindow"

 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 

 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 

 xmlns:controls="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls"

 Width="400" Height="300" 

 Title="EmployeeRegistrationWindow"

 HasCloseButton="False">

</controls:ChildWindow>

这里需要用到DataForm控件，所以在XAML里面声明下这个控件所在的命名空间： 

xmlns:dataForm="clr-namespace:System.Windows.Controls;assembly=System.Windows.Controls.Data.DataForm.Toolkit"

增加DataForm控件到EmployeeRegistrationWindow.xaml。 

<dataForm:DataForm x:Name="addEmployeeDataForm" AutoGenerateFields="False" AutoCommit="True" AutoEdit="True" CommandButtonsVisibility="None">

 <dataForm:DataForm.EditTemplate>

 <DataTemplate>

 <StackPanel>

 <dataForm:DataField Label="Login ID">

 <TextBox Text="{Binding LoginID, Mode=TwoWay}" />

 </dataForm:DataField>

 <dataForm:DataField Label="National ID">

 <TextBox Text="{Binding NationalIDNumber, Mode=TwoWay}" />

 </dataForm:DataField>

 <dataForm:DataField Label="Title">

 <TextBox Text="{Binding Title, Mode=TwoWay}" />

 </dataForm:DataField>

 <dataForm:DataField Label="Marital Status">

 <TextBox Text="{Binding MaritalStatus, Mode=TwoWay}" />

 </dataForm:DataField>

 <dataForm:DataField Label="Gender">

 <TextBox Text="{Binding Gender, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />

 </dataForm:DataField>

 <dataForm:DataField Label="Salaried">

 <CheckBox IsChecked="{Binding SalariedFlag, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />

 </dataForm:DataField>

 <dataForm:DataField Label="Active">

 <CheckBox IsChecked="{Binding CurrentFlag, Mode=TwoWay,NotifyOnValidationError=True, ValidatesOnExceptions=True }" />

 </dataForm:DataField>

 </StackPanel>

 </DataTemplate>

 </dataForm:DataForm.EditTemplate>

</dataForm:DataForm>

打开EmployeeRegistrationWindow.xaml.cs文件，加入下面的代码： 

public partial class EmployeeRegistrationWindow : ChildWindow

{

 public EmployeeRegistrationWindow()

 {

 InitializeComponent();

 NewEmployee = new Employee();

 addEmployeeDataForm.CurrentItem = NewEmployee;

 addEmployeeDataForm.BeginEdit(); 

 }

 private void OKButton_Click(object sender, RoutedEventArgs e)

 {

 addEmployeeDataForm.CommitEdit();

 this.DialogResult = true;

 }

 private void CancelButton_Click(object sender, RoutedEventArgs e)

 {

 NewEmployee = null;

 addEmployeeDataForm.CancelEdit();

 this.DialogResult = false;

 }

 public Employee NewEmployee { get; set; }

}

打开EmployeeList.xaml页面，增加一个Add按钮，放在DataPager和DataForm控件之间： 

<StackPanel Orientation="Horizontal" HorizontalAlignment="Right" Margin="0,12,0,0">

 <Button x:Name="addNewEmployee" Width="90" Height="23" Content="Add Employee" Margin="4,0,0,0" Click="addNewEmployee_Click"/>

</StackPanel>

实现按钮的单击事件，同时为新增的窗体增加关闭的事件： 

private void addNewEmployee_Click(object sender, RoutedEventArgs e)

{

 EmployeeRegistrationWindow addEmp = new EmployeeRegistrationWindow();

 addEmp.Closed += new EventHandler(addEmp_Closed);

 addEmp.Show();

}

void addEmp_Closed(object sender, EventArgs e)

{

 EmployeeRegistrationWindow emp = (EmployeeRegistrationWindow)sender;

 if (emp.NewEmployee != null)

 {

 OrganizationContext _OrganizationContext = (OrganizationContext)(employeeDataSource.DomainContext);

 _OrganizationContext.Employees.Add(emp.NewEmployee);

 employeeDataSource.SubmitChanges();

 }

}

新增的时候会调用OrganizationService.cs中的InsertEmployee方法。我们可以自定义这个方法。 

public void InsertEmployee(Employee employee)

{

 // Modify the employee data to meet the database constraints.

 employee.HireDate = DateTime.Now;

 employee.ModifiedDate = DateTime.Now;

 employee.VacationHours = 0;

 employee.SickLeaveHours = 0;

 employee.rowguid = Guid.NewGuid();

 employee.ContactID = 1001;

 employee.BirthDate = new DateTime(1967, 3, 18);

 if ((employee.EntityState != EntityState.Detached))

 {

 this.ObjectContext.ObjectStateManager.ChangeObjectState(employee, EntityState.Added);

 }

 else

 {

 this.ObjectContext.Employees.AddObject(employee);

 }

}

运行程序。 


http://www.cnblogs.com/sonce/archive/2011/02/26/1965896.html