DbRawSqlQuery<TElement>.ToDictionaryAsync<TKey, TResult> 方法 (Func<TElement, TKey>, Func<TElement, TResult>)
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通过异步枚举它根据指定的键选择器函数和元素选择器函数从查询创建 Dictionary<TKey, TValue>。
命名空间： System.Data.Entity.Infrastructure
程序集： EntityFramework（在 EntityFramework.dll 中）
语法
声明
<SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")> _
Public Function ToDictionaryAsync(Of TKey, TResult) ( _
keySelector As Func(Of TElement, TKey), _
elementSelector As Func(Of TElement, TResult) _
) As Task(Of Dictionary(Of TKey, TResult))
用法
Dim instance As DbRawSqlQuery
Dim keySelector As Func(Of TElement, TKey)
Dim elementSelector As Func(Of TElement, TResult)
Dim returnValue As Task(Of Dictionary(Of TKey, TResult))
returnValue = instance.ToDictionaryAsync(keySelector, _
elementSelector)
[SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")]
public Task<Dictionary<TKey, TResult>> ToDictionaryAsync<TKey, TResult>(
Func<TElement, TKey> keySelector,
Func<TElement, TResult> elementSelector
)
[SuppressMessageAttribute(L"Microsoft.Design", L"CA1006:DoNotNestGenericTypesInMemberSignatures")]
public:
generic<typename TKey, typename TResult>
Task<Dictionary<TKey, TResult>^>^ ToDictionaryAsync(
Func<TElement, TKey>^ keySelector,
Func<TElement, TResult>^ elementSelector
)
[<SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")>]
member ToDictionaryAsync :
keySelector:Func<'TElement, 'TKey> *
elementSelector:Func<'TElement, 'TResult> -> Task<Dictionary<'TKey, 'TResult>>
JScript does not support generic types and methods.
类型参数
- TKey
keySelector 返回的键类型。
- TResult
elementSelector 返回的值的类型。
参数
- keySelector
类型：System.Func<TElement, TKey>
用于从每个元素中提取键的函数。
- elementSelector
类型：System.Func<TElement, TResult>
用于从每个元素产生结果元素值的转换函数。
返回值
类型：System.Threading.Tasks.Task<Dictionary<TKey, TResult>>
表示异步操作的任务。任务结果包含一个 Dictionary<TKey, TValue>，后者包含从查询选择的类型 TResult 的值。
备注
不支持对同一上下文实例执行多个活动操作。 使用“await”以确保在对此上下文调用另一个方法前完成了所有异步操作。