我目前正在创建一个登录表单,并有以下代码:

string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
try
{
    using (OdbcConnection connect = new OdbcConnection(connectionString))
    {
        connect.Open();
        OdbcCommand cmd = new OdbcCommand("SELECT username, password FROM receptionist", connect);
        OdbcDataReader reader = cmd.ExecuteReader();

        if (username_login.Text == username && password_login.Text == password)
        {
            this.Hide();
            MessageBox.Show("Invalid User", "Login Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
            this.Close();
        }
        else 
            MessageBox.Show("Invalid User", "Login Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
        connect.Close();
    }
}
catch (OdbcException ex)
{
    MessageBox.Show(ex.Message, "error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

但每当我尝试输入用户名和密码时,就会出现一个名为“配置系统初始化失败”的错误。这是什么问题,我怎么解决它?


当前回答

同样的问题,我解决了我的问题,从App.config删除version ="v3.5"。

之前

 <?xml version="1.0" encoding="utf-8"?>
  <configuration>

  <startup>

 <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2"/>
 </startup>
 <supportedRuntime version="v3.5" />//Remove this
</configuration>

解决方案

<?xml version="1.0" encoding="utf-8"?>
<configuration>

  <startup>

    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5.2"/>
  </startup>
  </configuration>

下面是如何使用版本

MSDN支持运行时元素

其他回答

我尝试了上面所有的解决方案,试图弄清楚为什么我的一个单元测试无法从一个完美的app.config文件中获取配置。

我有2个对相同程序集的引用,如下所示:

删除(重复)参考在黄色固定它为我。

我希望这对其他人也有用,有段时间我都快疯了。

I know this has already been answered but I had exactly the same problem in my unit tests. I was tearing my hair out - adding an appSettings section, and then declaring the configuration section as per the answer. Finally found out that I had already declared an appSettings section further up my config file. Both sections pointed to my external settings file "appSettings.config" but the first appSettings element using the attribute file whilst the other used the attribute configSource. I know the question was about the connectionStrings. Sure enough, this happens if the appSettings element is the connectionStrings element being duplicated with different attributes.

希望这可以为其他人提供解决方案,以免他们重蹈我的覆辙,浪费一两个小时。感叹我们开发者的生活。有时候我们在调试上浪费的时间比在开发上还要多!

我在MSTest类中遇到了同样的问题:Marlon Grech在他的文章中说:“必须将元素定义为App.config中的第一个元素。”

确保这是元素下面的第一个元素。我把AppSettings放在第一位。

我还得到了

'System.Configuration.ConfigurationErrorsException' in System.Configuration.dll

如果你有窗口检查斜杠/我正在与一个在linux工作的人一起工作的项目,所以他颠倒了它们。

我通过使用下面的代码解决了这个问题

   <?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <sectionGroup name="applicationSettings"
                  type="System.Configuration.ApplicationSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >

      <section name="YourProjectName.Properties.Settings"
               type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"
               requirePermission="false" />

    </sectionGroup>

  </configSections>
  <appSettings>
    <add key="SPUserName" value="TestUser" />
    <add key="SPPassword" value="UserPWD" />
  </appSettings>
</configuration>