创建一个以连接字符串作为参数的构造函数。

Create a constructor that takes the connection string as a parameter.

public class classfile
{
    private string _connectionString;
    public classfile(string connectionString)
    {
        _connectionString = connectionString;
    }
}

现在你班上的任何地方都可以使用'_connectionString'成员。 （如果方法不是静态的）



无论你实例化你的类文件类，你都必须传递连接字符串。

Now everywhere in your class you can use the '_connectionString' member. (if the methods aren't static)

And everywhere you instantiate your classfile class you'll have to pass the connectionstring.