c# - 在 appSettings 中存储值

Question

我试图在我的配置文件中存储一个用户 ID，然后出于多种原因我想在整个程序中访问它。我在配置文件中有 appSettings 部分；

<appSettings>
  <add key="userID" value="1" />
</appSettings>

然后我在一个方法中设置值；

private void hrButton_Click(object sender, RoutedEventArgs e)
{
    DataAccessor da = new DataAccessor();
    DataRowView dataRow = (DataRowView)dataGrid.SelectedItem;

    // Open App.Config of executable
    Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

    // Add an Application Setting.
    config.AppSettings.Settings.Add("userID", dataRow.Row.ItemArray[0].ToString());

    // Save the changes in App.config file.
    config.Save(ConfigurationSaveMode.Modified);

    da.SetUserDetails();
    NavigationService.Navigate(new Uri(@"View/HRSystem/HRSystem.xaml", UriKind.Relative));
}

在尝试在另一个中访问和使用它之前；

public List<string> SetUserDetails()
{
    string userID = ConfigurationManager.AppSettings.Get("userID");
    MessageBox.Show("userID: "+userID);

    string constr = ConfigurationManager.ConnectionStrings["dbfString"].ConnectionString;
    using (OleDbConnection dbfCon = new OleDbConnection(constr))
    {
        try
        {
            dbfCon.Open();
            OleDbDataReader myReader;
            OleDbCommand sqlCmd = new OleDbCommand("SELECT em_pplid FROM employs WHERE em_pplid = "+ userID + "", dbfCon);
            myReader = sqlCmd.ExecuteReader();

            List<string> listUser = new List<string>();
            while (myReader.Read())
            {
                listUser.Add(myReader[0].ToString());
                return listUser;
            }
        }
        catch (MySqlException)
        {
            throw;
        }
    }
    return null;
}

然而，当我在消息框中显示 userID 时，它仍然设置为 1。我之前没有使用过 appSettings 部分，有什么原因吗总是1？我正在运行 Visual Studio 2015、C# WPF。

Answer 1

添加config.AppSettings.Settings.Remove("userID");在 config.AppSettings.Settings.Add(); 正上方的线上

但是保存此类信息的正确方法是使用 Settings File

设置:

Properties.Settings.Default.userID = dataRow.Row.ItemArray[0].ToString();
Properties.Settings.Default.Save();

检索:

var userId = Properties.Settings.Default.userID;