调用存储过程丢失输出参数小数点后面的数值

http://www.jianshu.com/p/355d96650ff1

需要手动指定保留位数就好，例子：

                        var allAmount = SqlDbType.Decimal.Out("AllAmount");
                        allAmount.Scale = 5;
                        allAmount.Precision = 18;
                        cmd.Parameters.Add(allAmount);