你需要一个参数 Direction 设置为 ParameterDirection.ReturnValue

You need a parameter with Direction set to ParameterDirection.ReturnValue

类似:

SqlParameter returnParameter = deleteCommand.Parameters.Add("RetVal", SqlDbType.Int);
returnParameter.Direction = ParameterDirection.ReturnValue;
...
deleteCommand.ExecuteNonQuery();
...
int returnValue = (int) returnParameter.Value;

你的存储过程当然需要返回这个返回值:

You Stored Procedure needs to return this return value of course:

create proc [dbo].[DeleteParts]      
    @TransNo nvarchar (6),   
    @fpart nvarchar(25)  
AS      
DECLARE @Returns BIT      
SET @Returns = 1     
...
RETURN @Returns