刚开始接触利用winform连接数据库.但数据库连接时却提示有错误.(具体请见图片)
可代码没有错.我把错误的提示截图.请大家帮忙看一下.
我是用VS 2005连接SQL2000.
谢谢.

代码:
using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;

namespace ADONETDemo
{
/// <summary>
/// Form1 的摘要说明。
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.ListBox listBox1;
private System.Windows.Forms.Button button1;
/// <summary>
/// 必需的设计器变量。
/// </summary>
private System.ComponentModel.Container components = null;

private SqlConnection con;
private SqlCommand cmd;
private System.Windows.Forms.Button button2;
private SqlDataReader dr;
public Form1()
{
//
// Windows 窗体设计器支持所必需的
//
InitializeComponent();

//
// TODO: 在 InitializeComponent 调用后添加任何构造函数代码
//
}

/// <summary>
/// 清理所有正在使用的资源。
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}

#region Windows 窗体设计器生成的代码
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.listBox1 = new System.Windows.Forms.ListBox();
this.button1 = new System.Windows.Forms.Button();
this.button2 = new System.Windows.Forms.Button();
this.SuspendLayout();
//
// listBox1
//
this.listBox1.ItemHeight = 12;
this.listBox1.Location = new System.Drawing.Point(8, 8);
this.listBox1.Name = "listBox1";
this.listBox1.Size = new System.Drawing.Size(176, 196);
this.listBox1.TabIndex = 0;
//
// button1
//
this.button1.Location = new System.Drawing.Point(216, 16);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(75, 23);
this.button1.TabIndex = 1;
this.button1.Text = "查询";
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// button2
//
this.button2.Location = new System.Drawing.Point(216, 72);
this.button2.Name = "button2";
this.button2.Size = new System.Drawing.Size(75, 23);
this.button2.TabIndex = 2;
this.button2.Text = "更新";
this.button2.Click += new System.EventHandler(this.button2_Click);
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(6, 14);
this.ClientSize = new System.Drawing.Size(424, 213);
this.Controls.Add(this.button2);
this.Controls.Add(this.button1);
this.Controls.Add(this.listBox1);
this.Name = "Form1";
this.Text = "Form1";
//this.Load += new System.EventHandler(this.Form1_Load);
this.ResumeLayout(false);

}
#endregion

/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}

private void button1_Click(object sender, System.EventArgs e)
{
try
{
con = new SqlConnection("server=113512;uid=sa;pwd=;database=test");
con.Open();
cmd = new SqlCommand("select * from test",con);
dr = cmd.ExecuteReader();
while(dr.Read())
{
string str = dr.GetString(0);
this.listBox1.Items.Add(str);
}
}
catch(SqlException ex)
{
MessageBox.Show(ex.Message);
}
finally
{
dr.Close();
con.Close();
}
}
}
}

[此贴子已经被作者于2007-11-12 10:39:57编辑过]