参数1无法从字符串转换为整数此消息显示 [英] Argument 1 Can Not Convert From Sting To Int This Message Show

问题描述

我想将一个组合框链接到数据库.为此，我编写了一个程序，但是却显示了一个问题.我的错误代码在下面

I Want To Link A Combobox To Database . For This I Write A Proggrame But One Problem Show .My Error Code Bellow

推荐答案

您应该检查DbDataReader类(或正在使用的DbDataReader派生类的文档).通用类没有使用String作为参数的GetString方法.相反，仅采用应该为序数的Int 数字.

you should check the DbDataReader class (or the documentation of the class you are using that derives of DbDataReader). The common classes does not have a GetString method that takes a String as argument. Instead only a Int is taken which should be the ordinal number.

您可能会打这样的电话:

You could have a call like this:

字符串sname = reader.GetString(reader.GetOrdinal(" Name")));

string sname = reader.GetString(reader.GetOrdinal("Name"));

(您甚至可以考虑创建一个扩展DbDataReader的类以具有这些方法.这样，您只需编写一次即可.另一个缺失"的实现是处理DbNull.因此，该方法可以为空值(例如 int?)并检查DbNull也很有用.)

(You might even think about creating a class that extends the DbDataReader to have these methods. That way you only have to code it once. The other implementation that is "missing" is handling DbNull. So a method that gets nullable values (e.g. int?) and checks for DbNull is also useful.)

以诚挚的问候，

康拉德

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