通过

IDbCommandInterceptor.ReaderExecutingAsync 方法

  • 参考

定义

命名空间:
Microsoft.EntityFrameworkCore.Diagnostics
程序集:
Microsoft.EntityFrameworkCore.Relational.dll
包:
Microsoft.EntityFrameworkCore.Relational v3.0.0
包:
Microsoft.EntityFrameworkCore.Relational v3.1.0
包:
Microsoft.EntityFrameworkCore.Relational v5.0.0
包:
Microsoft.EntityFrameworkCore.Relational v6.0.0
包:
Microsoft.EntityFrameworkCore.Relational v7.0.0
包:
Microsoft.EntityFrameworkCore.Relational v8.0.0

在 EF 打算调用 之前调用 ExecuteReaderAsync()。

public System.Threading.Tasks.Task<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>> ReaderExecutingAsync (System.Data.Common.DbCommand command, Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData eventData, Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> result, System.Threading.CancellationToken cancellationToken = default);
public System.Threading.Tasks.ValueTask<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>> ReaderExecutingAsync (System.Data.Common.DbCommand command, Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData eventData, Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> result, System.Threading.CancellationToken cancellationToken = default);
public virtual System.Threading.Tasks.ValueTask<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>> ReaderExecutingAsync (System.Data.Common.DbCommand command, Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData eventData, Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> result, System.Threading.CancellationToken cancellationToken = default);
abstract member ReaderExecutingAsync : System.Data.Common.DbCommand * Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData * Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> * System.Threading.CancellationToken -> System.Threading.Tasks.Task<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>>
abstract member ReaderExecutingAsync : System.Data.Common.DbCommand * Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData * Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>>
abstract member ReaderExecutingAsync : System.Data.Common.DbCommand * Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData * Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>>
override this.ReaderExecutingAsync : System.Data.Common.DbCommand * Microsoft.EntityFrameworkCore.Diagnostics.CommandEventData * Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader> * System.Threading.CancellationToken -> System.Threading.Tasks.ValueTask<Microsoft.EntityFrameworkCore.Diagnostics.InterceptionResult<System.Data.Common.DbDataReader>>
Public Function ReaderExecutingAsync (command As DbCommand, eventData As CommandEventData, result As InterceptionResult(Of DbDataReader), Optional cancellationToken As CancellationToken = Nothing) As Task(Of InterceptionResult(Of DbDataReader))
Public Function ReaderExecutingAsync (command As DbCommand, eventData As CommandEventData, result As InterceptionResult(Of DbDataReader), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of InterceptionResult(Of DbDataReader))
Public Overridable Function ReaderExecutingAsync (command As DbCommand, eventData As CommandEventData, result As InterceptionResult(Of DbDataReader), Optional cancellationToken As CancellationToken = Nothing) As ValueTask(Of InterceptionResult(Of DbDataReader))

参数

command
DbCommand

命令。

eventData
CommandEventData

有关命令和执行的上下文信息。

result
InterceptionResult<DbDataReader>

表示当前结果（如果存在）。 如果某个以前的侦听器通过调用 SuppressWithResult(TResult)来禁止执行，则此值将HasResult设置为 true 。 此值通常用作此方法实现的返回值。

cancellationToken
CancellationToken

等待 CancellationToken 任务完成时要观察的 。

返回

Task<InterceptionResult<DbDataReader>>
ValueTask<InterceptionResult<DbDataReader>>

如果 HasResult 为 false，EF 将照常继续。 如果 HasResult 为 true，则 EF 将取消它要执行的操作并改为使用 Result 。 对于任何不尝试更改结果的侦听器，此方法的实现是返回 result 传入的值，通常使用 FromResult<TResult>(TResult)

例外

OperationCanceledException

如果已取消 CancellationToken。

适用于