网上找到的一个数据基类,有一个带ref参数的方法 /// <summary>
/// 返回指定Sql语句的SqlDataReader,请注意,在使用后请关闭本对象,同时将自动调用closeConnection()来关闭数据库连接
/// 方法关闭数据库连接
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="dr">传入的ref DataReader 对象</param>
public static void dataReader(string sqlstr,ref SqlDataReader dr)
{
try
{
openConnection();
comm.CommandText =sqlstr;
comm.CommandType =CommandType.Text ;
dr=comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
if(dr!=null && !dr.IsClosed)
dr.Close();
}
catch
{
}
finally
{
closeConnection();
}
}
}
但不知具体怎么用,比如选取一个表的数据绑定至DataGrid!!!哪位大侠给几行代码或思路,先谢了!
/// 返回指定Sql语句的SqlDataReader,请注意,在使用后请关闭本对象,同时将自动调用closeConnection()来关闭数据库连接
/// 方法关闭数据库连接
/// </summary>
/// <param name="sqlstr">传入的Sql语句</param>
/// <param name="dr">传入的ref DataReader 对象</param>
public static void dataReader(string sqlstr,ref SqlDataReader dr)
{
try
{
openConnection();
comm.CommandText =sqlstr;
comm.CommandType =CommandType.Text ;
dr=comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch
{
try
{
if(dr!=null && !dr.IsClosed)
dr.Close();
}
catch
{
}
finally
{
closeConnection();
}
}
}
但不知具体怎么用,比如选取一个表的数据绑定至DataGrid!!!哪位大侠给几行代码或思路,先谢了!
// cs_ref.cs
using System;
public class MyClass
{
public static void TestRef(ref char i)
{
// The value of i will be changed in the calling method
i = 'b';
} public static void TestNoRef(char i)
{
// The value of i will be unchanged in the calling method
i = 'c';
} // This method passes a variable as a ref parameter; the value of the
// variable is changed after control passes back to this method.
// The same variable is passed as a value parameter; the value of the
// variable is unchanged after control is passed back to this method.
public static void Main()
{
char i = 'a'; // variable must be initialized
TestRef(ref i); // the arg must be passed as ref
Console.WriteLine(i);
TestNoRef(i);
Console.WriteLine(i);
}
}
输出
b
b
为什么不直接
public static SqlDataReader dataReader(string sqlstr)