DataServiceQuery<TElement>.AddQueryOption(String, Object) 方法

定義

命名空間:

System.Data.Services.Client

組件:

System.Data.Services.Client.dll

以傳回的查詢所產生之 URI 中設定的查詢選項來建立新的 DataServiceQuery<TElement>。

public:
 System::Data::Services::Client::DataServiceQuery<TElement> ^ AddQueryOption(System::String ^ name, System::Object ^ value);

public System.Data.Services.Client.DataServiceQuery<TElement> AddQueryOption (string name, object value);

member this.AddQueryOption : string * obj -> System.Data.Services.Client.DataServiceQuery<'Element>

Public Function AddQueryOption (name As String, value As Object) As DataServiceQuery(Of TElement)

參數

name

String

字串值，包含要加入之查詢字串選項的名稱。

value

Object

物件，包含查詢字串選項的值。

傳回

DataServiceQuery<TElement>

新的查詢，其中包含附加至所提供查詢 URI 的要求查詢選項。

範例

下列範例示範 DataServiceQuery<TElement> 搭配使用循序 AddQueryOption 方法呼叫，只傳回運費超過 $30 美元的訂單，並按出貨日期遞減排序結果。

// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);

// Define a query for orders with a Freight value greater than 30
// and that is ordered by the ship date, descending.
DataServiceQuery<Order> selectedOrders = context.Orders
    .AddQueryOption("$filter", "Freight gt 30")
    .AddQueryOption("$orderby", "OrderID desc");

try
{
    // Enumerate over the results of the query.
    foreach (Order order in selectedOrders)
    {
        Console.WriteLine("Order ID: {0} - Ship Date: {1} - Freight: {2}",
            order.OrderID, order.ShippedDate, order.Freight);
    }
}
catch (DataServiceQueryException ex)
{
    throw new ApplicationException(
        "An error occurred during query execution.", ex);
}

' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)

' Define a query for orders with a Freight value greater than 30
' and that is ordered by the ship date, descending.
Dim selectedOrders As DataServiceQuery(Of Order) = context.Orders _
.AddQueryOption("$filter", "Freight gt 30") _
.AddQueryOption("$orderby", "OrderID desc")

Try
    ' Enumerate over the results of the query.
    For Each order As Order In selectedOrders
        Console.WriteLine("Order ID: {0} - Ship Date: {1} - Freight: {2}", _
                order.OrderID, order.ShippedDate, order.Freight)
    Next
Catch ex As DataServiceQueryException
    Throw New ApplicationException( _
            "An error occurred during query execution.", ex)
End Try

下列範例示範如何撰寫相當於前一個查詢 (使用 AddQueryOption) 的 LINQ 查詢。

// Create the DataServiceContext using the service URI.
NorthwindEntities context = new NorthwindEntities(svcUri);

// Define a query for orders with a Freight value greater than 30
// and that is ordered by the ship date, descending.
var selectedOrders = from o in context.Orders
                     where o.Freight > 30
                     orderby o.ShippedDate descending
                     select o;

try
{
    // Enumerate over the results of the query.
    foreach (Order order in selectedOrders)
    {
        Console.WriteLine("Order ID: {0} - Ship Date: {1} - Freight: {2}",
            order.OrderID, order.ShippedDate, order.Freight);
    }
}
catch (DataServiceQueryException ex)
{
    throw new ApplicationException(
        "An error occurred during query execution.", ex);
}

' Create the DataServiceContext using the service URI.
Dim context = New NorthwindEntities(svcUri)

' Define a query for orders with a Freight value greater than 30
' and that is ordered by the ship date, descending.
Dim selectedOrders = From o In context.Orders _
        Where (o.Freight > 30) _
        Order By o.ShippedDate Descending _
        Select o

Try
    ' Enumerate over the results of the query.
    For Each order As Order In selectedOrders
        Console.WriteLine("Order ID: {0} - Ship Date: {1} - Freight: {2}", _
                order.OrderID, order.ShippedDate, order.Freight)
    Next
Catch ex As DataServiceQueryException
    Throw New ApplicationException( _
            "An error occurred during query execution.", ex)
End Try

備註

查詢選項會使用 ?name=value&name2=value2... 新增至結果 URI 語法，其中名稱會直接對應至 name 參數， value 並在 參數上 value 呼叫ToString來取得 。 name 會以 $ 為開頭。

非 WCF Data Services 語法不是以 $開頭。 您可以使用此方法來新增非 WCF Data Services 查詢選項。 如果選項不是 WCF Data Services 查詢選項，則新增相同的查詢選項兩次是合法的。 如果被加入的查詢已經在基礎 URI 中，則會擲回例外狀況 (Exception)。