要求调用存储过程C＃的合法示例：MYSQL

您应该设置对参数的引用

var param3 = new MySqlParameter();param3.Direction = ParameterDirection.Output;param3.DbType = // whatever the dbtype for int is or whatever you need.param3.ParameterName = "param3";com.Parameters.Add(param3);

在您的try块中，插入

var result = com.ExecuteReader(); // or com.ExecuteScalar();

执行完该操作之后，您的参数应已填充值，并且还应该能够读取SP结果（选择）。

var paramResult = param3.Value;

可以以读取器或标量读取SP的结果。

// execute readerwhile (result.Read()) {    int value = result.GetInt32(0)); } // execute scalarint value;if (int.TryParse($"{result}", out value)) {     }

/ ********** /

这个街区应该可以让您到达需要去的地方

        const string strcon = "whatevs";        using (MySqlConnection con = new MySqlConnection(strcon))        { const string sql = "login"; MySqlCommand com = new MySqlCommand(sql, con); com.CommandType = CommandType.StoredProcedure; var stuffParam = new MySqlParameter("stuff", stuffValue); var passParam = new MySqlParameter("pass", passValue); var param3Param = new MySqlParameter(); param3Param.ParameterName = "param3"; param3Param.DbType = DbType.Int32; param3Param.Direction = ParameterDirection.Output; com.Parameters.Add(stuffParam); com.Parameters.Add(passParam); com.Parameters.Add(param3Param); try {     var scalarResult = com.ExecuteScalar();     // because you used select @param3 in your sp.     int value;     if (int.TryParse($"{scalarResult}", out value))     {         //do something with value     }     //// because you used select @param3 in your sp.     //var readerResult = com.ExecuteReader();     //if (readerResult.Read())     //{     //    //      //    value = readerResult.GetInt32(0);     //}     int param3Returned;     if(int.TryParse($"{param3Param.Value}", out param3Returned))     {         // do something with param3Returned     } } catch (Exception ex) {     // do something with ex }        }