从同步I / O绑定方法开始(如下所示),如何使用async / await使其异步?
public int Iobound(sqlConnection conn,sqlTransaction tran) { // this stored procedure takes a few seconds to complete sqlCommand cmd = new sqlCommand("MyIoboundStoredProc",conn,tran); cmd.CommandType = CommandType.StoredProcedure; sqlParameter returnValue = cmd.Parameters.Add("ReturnValue",sqlDbType.Int); returnValue.Direction = ParameterDirection.ReturnValue; cmd.ExecuteNonQuery(); return (int)returnValue.Value; }
MSDN示例都假设存在* Async方法,并且没有为I / O绑定操作自己创建一个指导.
我可以使用Task.Run()并在该新任务中执行Iobound(),但不鼓励创建新任务,因为该操作不受cpu限制.
我想使用async / await,但我仍然坚持这个如何继续转换此方法的基本问题.
解决方法
转换此特定方法非常简单:
// change return type to Task<int> public async Task<int> Iobound(sqlConnection conn,sqlTransaction tran) { // this stored procedure takes a few seconds to complete using (sqlCommand cmd = new sqlCommand("MyIoboundStoredProc",tran)) { cmd.CommandType = CommandType.StoredProcedure; sqlParameter returnValue = cmd.Parameters.Add("ReturnValue",sqlDbType.Int); returnValue.Direction = ParameterDirection.ReturnValue; // use async IO method and await it await cmd.ExecuteNonQueryAsync(); return (int) returnValue.Value; } }