WinForm连接数据库

操作环境，VS2015，SQL Sever2008

1.App.config文件的引用

在生成的App.config文件中

原代码为：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
    </startup>
</configuration>

使用<appSettings>或<connectionStrings>设置连接数据库参数

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <appSettings>
    <add key="server" value="服务器名"/>
    <add key="db" value="数据库名"/>
    <add key="user" value="登录名"/>
    <add key="pwd" value="密码"/>
  </appSettings>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2" />
  </startup>
</configuration>

在窗体代码中添加

private bool connect()
    {
        string  server, db, user, pwd，USERCODE，USERNAME  ;
        StringBuilder errMsg = new StringBuilder("");//报错信息初始化
         
        //打开config文件
        Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
            
        //设置数据库连接参数
        server = config.AppSettings.Settings["server"].Value;
        db = config.AppSettings.Settings["db"].Value;
        user = config.AppSettings.Settings["user"].Value;
        pwd = config.AppSettings.Settings["pwd"].Value;
        //用户名
        USERCODE = config.AppSettings.Settings["usercode"].Value;
        USERNAME = config.AppSettings.Settings["username"].Value;

        if (!SysEnvironment.CONN.connectDB(server, db, user, pwd, errMsg))
        {
            //连接参数错误
            MessageBox.Show("数据库连接失败：" + errMsg.ToString());
            return false;
        }

        //打开数据库链接
        SysEnvironment.CONN.openConnection();
        lblInfo.Text = "连接数据库成功......";
        return true;
    }