DataServiceQueryContinuation<T> 类

封装返回已分页的 WCF 数据服务 查询结果的下一页的 URI。 

继承层次结构

System.Object
  System.Data.Services.Client.DataServiceQueryContinuation
    System.Data.Services.Client.DataServiceQueryContinuation<T>

命名空间：  System.Data.Services.Client
程序集：  Microsoft.Data.Services.Client（在 Microsoft.Data.Services.Client.dll 中）

语法

声明
Public NotInheritable Class DataServiceQueryContinuation(Of T) _
    Inherits DataServiceQueryContinuation
用法
Dim instance As DataServiceQueryContinuation(Of T)

public sealed class DataServiceQueryContinuation<T> : DataServiceQueryContinuation

generic<typename T>
public ref class DataServiceQueryContinuation sealed : public DataServiceQueryContinuation

[<SealedAttribute>]
type DataServiceQueryContinuation<'T> =  
    class
        inherit DataServiceQueryContinuation
    end

JScript 不支持一般类型和方法。

类型参数

• T
  延续令牌的类型。

DataServiceQueryContinuation<T> 类型公开以下成员。

属性

	名称	说明
	NextLinkUri	获取用于从已分页的查询结果返回数据的下一页的 URI。 （从 DataServiceQueryContinuation 继承。）

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方法

	名称	说明
	Equals	（从 Object 继承。）
	Finalize	（从 Object 继承。）
	GetHashCode	（从 Object 继承。）
	GetType	（从 Object 继承。）
	MemberwiseClone	（从 Object 继承。）
	ToString	以字符串形式返回下一个链接 URI。 （从 DataServiceQueryContinuation 继承。）

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示例

下面的示例使用 do…while 循环从数据服务的分页结果中加载 Customers 实体。

' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)
Dim token As DataServiceQueryContinuation(Of Customer) = Nothing
Dim pageCount = 0

Try
    ' Execute the query for all customers and get the response object.
    Dim response As QueryOperationResponse(Of Customer) = _
        CType(context.Customers.Execute(), QueryOperationResponse(Of Customer))

    ' With a paged response from the service, use a do...while loop 
    ' to enumerate the results before getting the next link.
    Do
        ' Write the page number.
        Console.WriteLine("Page {0}:", pageCount + 1)

        ' If nextLink is not null, then there is a new page to load.
        If token IsNot Nothing Then
            ' Load the new page from the next link URI.
            response = CType(context.Execute(Of Customer)(token),  _
            QueryOperationResponse(Of Customer))
        End If

        ' Enumerate the customers in the response.
        For Each customer As Customer In response
            Console.WriteLine(vbTab & "Customer Name: {0}", customer.CompanyName)
        Next

        ' Get the next link, and continue while there is a next link.
        token = response.GetContinuation()
    Loop While token IsNot Nothing
Catch ex As DataServiceQueryException
    Throw New ApplicationException( _
            "An error occurred during query execution.", ex)
End Try

// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);
DataServiceQueryContinuation<Customer> token = null;
int pageCount = 0; 

try
{ 
    // Execute the query for all customers and get the response object.
    QueryOperationResponse<Customer> response =
        context.Customers.Execute() as QueryOperationResponse<Customer>;

    // With a paged response from the service, use a do...while loop 
    // to enumerate the results before getting the next link.
    do
    {
        // Write the page number.
        Console.WriteLine("Page {0}:", pageCount++);

        // If nextLink is not null, then there is a new page to load.
        if (token != null)
        {
            // Load the new page from the next link URI.
            response = context.Execute<Customer>(token)
                as QueryOperationResponse<Customer>;
        }

        // Enumerate the customers in the response.
        foreach (Customer customer in response)
        {
            Console.WriteLine("\tCustomer Name: {0}", customer.CompanyName);
        }
    }

    // Get the next link, and continue while there is a next link.
    while ((token = response.GetContinuation()) != null);
}
catch (DataServiceQueryException ex)
{
    throw new ApplicationException(
        "An error occurred during query execution.", ex);
}

线程安全

此类型的任何公共 static（在 Visual Basic 中为 Shared） 成员都是线程安全的。不保证所有实例成员都是线程安全的。

请参阅

参考

System.Data.Services.Client 命名空间

其他资源

加载延迟的内容（WCF 数据服务）