DataServiceRequest<TElement> 类

定义

命名空间:

System.Data.Services.Client

程序集:

System.Data.Services.Client.dll

表示作为批处理提交到数据服务的请求对象。

generic <typename TElement>
public ref class DataServiceRequest sealed : System::Data::Services::Client::DataServiceRequest

public sealed class DataServiceRequest<TElement> : System.Data.Services.Client.DataServiceRequest

type DataServiceRequest<'Element> = class
    inherit DataServiceRequest

Public NotInheritable Class DataServiceRequest(Of TElement)
Inherits DataServiceRequest

类型参数

TElement

继承

Object

DataServiceRequest

DataServiceRequest<TElement>

示例

返回时 ExecuteBatch ，批处理请求的整个 HTTP 响应已从网络流中读取，但尚未处理响应。 响应中指定实体的标识解析和对象具体化在迭代之前不会发生，如以下示例所示。

DataServiceContext service = new DataServiceContext(new   
                                                    Uri("http://myserviceroot"));  

// Create query batches.  
DataServiceRequest[] reqs = new DataServiceRequest[] {   
    new DataServiceRequest<Category>(  
            new Uri("http://myserviceroot/Categories")),  
            new DataServiceRequest<Customer>(  
            new Uri("http://myserviceroot/Customers"))  
};  

DataServiceResponse dsr;  
try  
{  
    // Client will not throw an exception on ExecuteBatch because the   
    // entire response has not been processed yet to know  
    // whether an exception should be thrown.  

    dsr = service.ExecuteBatch(reqs);     

    if (dsr.IsBatchResponse)   
    {  
        /*inspect HTTP artifacts associated with the entire batch:  
                      dsr.BatchHeaders, dsr.BatchStatusCode*/ }  

    foreach (QueryOperationResponse qr in dsr)  
    {  
        if (IsErrorStatusCode(qr.StatusCode))     
        {  
            //q.Error.Message contains the full contents of the error.  
            /* process any part of the Error Contract (<error> element)  
                      sent from the service.  */  
            }  
        }  
        else  
        {  
            if (qr.Query.ElementType == typeof(Customer))  
            {  
                //process customers  
                foreach (Customer c in qr){ /*process the customer*/ }  

                // the DataServiceContext does not materialize, resolve  
                // identity on Customer until it is enumerated.  
            }  
            else if (qr.Query.ElementType == typeof(Category))  
            {  
                // Process categories.  
                foreach (Category cat in qr)  
                {   
                    /*process the category*/   
                 }  
                // the DataServiceContext does not materialize or  
                // resolve identity on the Category until  
                // it is enumerated.  
                // This means that instream errors will be thrown  
                // during iteration.  
            }  
        }  
    }  
}  
catch (DataServiceRequestException e)  
{  
    // This error is thrown if the data service returns with  
    // a response code < 200 or >299 or the top level element.  
    // If neither of the above or true, this exception is not   
    // thrown.  

    dsr = e.Response;  

    if (dsr.IsBatchResponse)   
    {   
        /*inspect HTTP artifacts associated with the entire batch:  
                        dsr.BatchHeaders, dsr.BatchStatusCode*/   
    }  

    /* There will always only be one of these because if the top level  
     status code was >=200 and =<299 and the first element was not an  
     error, the call to start the query will not throw. */  

    foreach (QueryOperationResponse qr in dsr)  
    {  
        if (qr.Error != null)  
        {  
            // Process error.  
        }  
    }     
}  

注解

在以批处理形式提交到数据服务的一组查询中，查询被指定为 DataServiceRequest<TElement> 实例。 返回一个 DataServiceResponse ，表示批处理请求作为一个整体的响应。 单个查询响应表示为 QueryOperationResponse 派生自 OperationResponse的对象，这些对象可通过枚举 DataServiceResponse 实例进行访问。

构造函数

DataServiceRequest<TElement>(Uri)

初始化 DataServiceRequest<TElement> 类的新实例。

属性

ElementType	获取用于创建 DataServiceRequest<TElement> 实例的对象的类型。
RequestUri	获取包含请求字符串的 URI 对象。

方法

Equals(Object)	确定指定对象是否等于当前对象。 (继承自 Object)
GetHashCode()	作为默认哈希函数。 (继承自 Object)
GetType()	获取当前实例的 Type。 (继承自 Object)
MemberwiseClone()	创建当前 Object 的浅表副本。 (继承自 Object)
ToString()	表示对数据服务的查询的 URI。 (继承自 DataServiceRequest)