误信息:未将对象引用设置到对象的实例。
这个是为啥啊~以下是代码
DBConnection是一个数据库连接DLL
不知道是什么原因!
using System;
using System.Collections.Generic;
using System.Text;
using DBConnection; namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
DBConnection.MSSQLConnection sqlconn = new DBConnection.MSSQLConnection(); try
{
sqlconn.GetConnection().Open();
Console.WriteLine("连接成功");
}
catch (Exception ex)
{
Console.WriteLine("出错了:" + ex.Message);
}
Console.ReadLine();
}
}
}DBConnection的代码如下
using System;
using System.Collections.Generic;
using System.Text;namespace DBConnection
{
public class MSSQLConnection
{ private System.Data.SqlClient.SqlConnection conn = null;
/// <summary>
/// 得到数据库连接。
/// </summary>
/// <returns>System.Data.SqlClient.SqlConnection</returns>
public System.Data.SqlClient.SqlConnection GetConnection()
{
return conn;
}
/// <summary>
/// 读取配置文件信息
/// </summary>
/// <returns>System.string</returns>
private string ReadConfig()
{
//读取穿在于临时文件的登录地址信息
string Userid = null;
string pasword = null;
string add = null;
string Linkadd = null;
System.Data.DataSet xmlDataSet = new System.Data.DataSet();
try
{
xmlDataSet.ReadXml(@"Config\LinkAddLog.xml");
foreach (System.Data.DataRow custRow in xmlDataSet.Tables["UserConnection"].Rows)
{
add = custRow["ConnectionAdd"].ToString();
Userid = custRow["ConnectionUserID"].ToString();
pasword = custRow["ConnectionPwd"].ToString();
}
}
catch (Exception ex)
{
throw ex; } Linkadd = "server="+add+";user id ="+Userid+";pwd="+pasword+";database=ActualizeManageSystem"; return Linkadd; }
/// <summary>
/// 生成数据库连接对象
/// </summar>
/// <returns></returns>
private void CreateConnection()
{
try
{
conn = new System.Data.SqlClient.SqlConnection(ReadConfig());
}
catch (System.Data.SqlClient.SqlException ex)
{
throw ex;
} }
}
}
这个是为啥啊~以下是代码
DBConnection是一个数据库连接DLL
不知道是什么原因!
using System;
using System.Collections.Generic;
using System.Text;
using DBConnection; namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
DBConnection.MSSQLConnection sqlconn = new DBConnection.MSSQLConnection(); try
{
sqlconn.GetConnection().Open();
Console.WriteLine("连接成功");
}
catch (Exception ex)
{
Console.WriteLine("出错了:" + ex.Message);
}
Console.ReadLine();
}
}
}DBConnection的代码如下
using System;
using System.Collections.Generic;
using System.Text;namespace DBConnection
{
public class MSSQLConnection
{ private System.Data.SqlClient.SqlConnection conn = null;
/// <summary>
/// 得到数据库连接。
/// </summary>
/// <returns>System.Data.SqlClient.SqlConnection</returns>
public System.Data.SqlClient.SqlConnection GetConnection()
{
return conn;
}
/// <summary>
/// 读取配置文件信息
/// </summary>
/// <returns>System.string</returns>
private string ReadConfig()
{
//读取穿在于临时文件的登录地址信息
string Userid = null;
string pasword = null;
string add = null;
string Linkadd = null;
System.Data.DataSet xmlDataSet = new System.Data.DataSet();
try
{
xmlDataSet.ReadXml(@"Config\LinkAddLog.xml");
foreach (System.Data.DataRow custRow in xmlDataSet.Tables["UserConnection"].Rows)
{
add = custRow["ConnectionAdd"].ToString();
Userid = custRow["ConnectionUserID"].ToString();
pasword = custRow["ConnectionPwd"].ToString();
}
}
catch (Exception ex)
{
throw ex; } Linkadd = "server="+add+";user id ="+Userid+";pwd="+pasword+";database=ActualizeManageSystem"; return Linkadd; }
/// <summary>
/// 生成数据库连接对象
/// </summar>
/// <returns></returns>
private void CreateConnection()
{
try
{
conn = new System.Data.SqlClient.SqlConnection(ReadConfig());
}
catch (System.Data.SqlClient.SqlException ex)
{
throw ex;
} }
}
}
DBConnection.MSSQLConnection sqlconn = new DBConnection.MSSQLConnection(); try
{
sqlconn.GetConnection().Open(); 直接调用构造函数,然后就打开。。但是public System.Data.SqlClient.SqlConnection GetConnection()
{
return conn; conn还没有初始化就返回了