C#中的数据库配置和连接
1.
向项目添加
app.config
文件：
右击项目名称，选择
“
添加
”
→
“
添加新建项
”
，在出现的
“
添加新项
”
对话框中，选择
“
添加应用程序配置文件
”
；如果项目以前没有配置文件，则默认的文件名称为
“app.config”
，单击
“
确定
”
。出现在解决方案资源管理器中的
app.config
文件为：
<? xml version ="1.0" encoding ="utf-8" ?>
< configuration >
</ configuration >
< configuration >
</ configuration >
2. connectionStrings
配置节：
请注意：如果您的
SQL
版本为
2005 Express
版，则默认安装时
SQL
服务器实例名为
localhost\SQLExpress
，须更改以下实例中
“Data Source=****;”
一句为
“Data Source=localhost\SQLExpress;”
，在等于号的两边不要加上空格。
如本例中：
< connectionStrings >
< clear />
< add name ="ProConnectionString" connectionString ="Data Source=172.18.139.215;Initial Catalog=NEWDB;User ID=dba;Password=dba" />
</ connectionStrings >
< clear />
< add name ="ProConnectionString" connectionString ="Data Source=172.18.139.215;Initial Catalog=NEWDB;User ID=dba;Password=dba" />
</ connectionStrings >
3. appSettings
配置节：
appSettings
配置节为整个程序的配置，如果是对当前用户的配置，请使用
userSettings
配置节，其格式与以下配置书写要求一样。
< appSettings >
< add key ="isFirstRunSystem" value ="true" />
</ appSettings >
< add key ="isFirstRunSystem" value ="true" />
</ appSettings >
C#
中的数据库配置
App.config
文件：
<? xml version ="1.0" encoding ="utf-8" ?>
< configuration >
< appSettings >
< add key ="isFirstRunSystem" value ="true" />
</ appSettings >
</ configuration >
< configuration >
< appSettings >
< add key ="isFirstRunSystem" value ="true" />
</ appSettings >
</ configuration >
4.
读取和更新配置节
FrmDBConfig.cs
/*----------------------------------------------------------------
// Copyright (C) Project
// 文件名：
// 文件功能描述：进行数据库配置和连接
//
//
// 创建标识：
//
// 修改标识：
// 修改描述：
----------------------------------------------------------------*/
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.ProviderBase;
using System.Data.SqlClient;
namespace Kitchen.UI
{
public partial class FrmDBConfig : Form
{
public FrmDBConfig()
{
InitializeComponent();
BindDataServer();
}
public FrmDBConfig(FrmWelcome fw)
{
InitializeComponent();
BindDataServer();
fw.Close();
}
/// <summary>
/// 测试数据库连接
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void button1_Click( object sender, EventArgs e)
{
if (txtPassWord.Text.Trim() == "" || cbServerName.Text.Trim() == "" || txtUsername.Text.Trim() == "")
{
MessageBox.Show( "输入服务器名(或者IP)、用户名和密码");
return;
}
string connStr = string.Format( "Data Source={0};User ID={1};Password={2}", cbServerName.Text.Trim(), txtUsername.Text.Trim(), txtPassWord.Text.Trim());
SqlConnection conn = new SqlConnection(connStr); // sqlcp = new SqlClientPermission()
//建立连接
try
{
//myConn = new SqlConnection(connStr);
conn.Open();
}
catch (Exception ee)
{
MessageBox.Show( "连接失败");
return;
}
MessageBox.Show( "连接成功");
}
private void button4_Click( object sender, EventArgs e)
{
this.Close();
}
private void button2_Click( object sender, EventArgs e)
{
if (txtPassWord.Text.Trim() == "" || cbServerName.Text.Trim() == "" || txtUsername.Text.Trim() == "")
{
MessageBox.Show( "输入服务器名(或者IP)、用户名和密码");
return;
}
if ((System.Configuration.ConfigurationSettings.AppSettings.GetValues( "isFirstRunSystem"))[0] == "true")
{
try
{
string str = string.Format( "data source ={0};initial catalog={1};user id={2};password={3};",
cbServerName.Text.Trim(), txtDBName.Text.Trim(), txtUsername.Text.Trim(), txtPassWord.Text);
Kitchen.Util.Config cc = new Kitchen.Util.Config();
cc.UpdateDBConfig( "ProConnectionString ", str, "System.Data.SqlClient");
MessageBox.Show( "配置成功,软件将自动重启动。"); //更新配置节
cc.UpdateConfig( "isFirstRunSystem", "false"); //更新配置节
this.Close();
Application.Restart();
}
catch (Exception ee)
{
MessageBox.Show( "配置失败\n" + ee.Message, "错误");
}
}
else
{
try
{
string str = string.Format( "data source ={0};initial catalog={1};user id={2};password={3};",
cbServerName.Text.Trim(), txtDBName.Text.Trim(), txtUsername.Text.Trim(), txtPassWord.Text);
Kitchen.Util.Config cc = new Kitchen.Util.Config();
cc.UpdateDBConfig( "ProConnectionString ", str, "System.Data.SqlClient");
if (MessageBox.Show( "更新成功,是否重新启动软件？", "提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question) == DialogResult.Yes)
{
this.Close();
Application.Restart();
}
else
{
this.Close();
}
}
catch (Exception ee)
{
MessageBox.Show( "配置失败\n" + ee.Message, "错误");
}
}
}
private void BindDataServer()
{
System.Data.Sql.SqlDataSourceEnumerator sdse = System.Data.Sql.SqlDataSourceEnumerator.Instance;
DataTable dt = sdse.GetDataSources();
cbServerName.DataSource = dt;
cbServerName.DisplayMember = "ServerName";
}
}
}
Config.cs
文件：
/*----------------------------------------------------------------/
Copyright (C)版权所有。
文件名：
文件功能描述：更新connectionStrings配置节
修改标识：
修改描述：
/----------------------------------------------------------------*/
using System;
using System.Collections.Generic;
using System.Text;
using System.Xml;
using System.Windows.Forms;
namespace Kitchen.Util
{
public class Config
{
//更新app.config的函数
//配置文件的源文件
//<?xml version="1.0" encoding="utf-8" ?>
//<configuration>
//<appSettings>
//<add key="ServerName" value=""/>
//</appSettings>
//</configuration>
/// <summary>
/// 更新app.config的数据库连接字符串函数
/// </summary>
/// <param name="connstrname">连接字符串名称</param>
/// <param name="connstr">连接字符串</param>
public void UpdateDBConfig( string connstrname, string connstr, string providername)
{
XmlDocument doc = new XmlDocument();
doc.Load(Application.ExecutablePath+ ".config");
XmlNode node = doc.SelectSingleNode( @"//add[@name='" + connstrname + "']");
XmlElement ele = (XmlElement)node;
ele.SetAttribute("connectionString", connstr);
ele.SetAttribute("providerName", providername);
doc.Save(Application.ExecutablePath+".config");
}
/// <summary>
/// 修改config中<add key ='keyname' value='keyvalue' />
/// </summary>
/// <param name="keyname">键名称</param>
/// <param name="keyvalue">键值</param>
public void UpdateConfig(string keyname,string keyvalue) {
XmlDocument doc = new XmlDocument();
doc.Load(Application.ExecutablePath + ".config");
XmlNode node = doc.SelectSingleNode(@"//add[@key='" + keyname + "']");
XmlElement ele = (XmlElement)node;
ele.SetAttribute("value", keyvalue);
doc.Save(Application.ExecutablePath + ".config");
}
}
}