Add values to app.config and retrieve them

问题

I need to insert key value pairs in app.Config as follows:

<configuration>
 <appSettings>
    <add key="Setting1" value="Value1" />
    <add key="Setting2" value="Value2" />
 </appSettings>
</configuration>

When I searched in google I got the following code snippet

System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None); // Add an Application Setting.

config.AppSettings.Settings.Add("ModificationDate",
               DateTime.Now.ToLongTimeString() + " ");

// Save the changes in App.config file.

config.Save(ConfigurationSaveMode.Modified);

The above code is not working as ConfigurationManager is not found in System.Configuration namespace I'm using .NET 2.0. How to add key-value pairs to app.Config programatically and retrieve them?

回答1:

Are you missing the reference to System.Configuration.dll? ConfigurationManager class lies there.

EDIT: The System.Configuration namespace has classes in mscorlib.dll, system.dll and in system.configuration.dll. Your project always include the mscorlib.dll and system.dll references, but system.configuration.dll must be added to most project types, as it's not there by default...

回答2:

This works:

public static void AddValue(string key, string value)
{
    Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
    config.AppSettings.Settings.Add(key, value);
    config.Save(ConfigurationSaveMode.Minimal);
}

回答3:

Try adding a Reference to System.Configuration, you get some of the configuration namespace by referencing the System namespace, adding the reference to System.Configuration should allow you to access ConfigurationManager.

回答4:

I hope this works:

System.Configuration.Configuration config= ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);

config.AppSettings.Settings["Yourkey"].Value = "YourValue";
config.Save(ConfigurationSaveMode.Modified);

回答5:

To Get The Data From the App.config

Keeping in mind you have to:

Added to the References -> System.Configuration
and also added this using statement -> using System.Configuration;

Just Simply do this

string value1 = ConfigurationManager.AppSettings["Value1"];

Alternatively, you can achieve this in one line, if you don't want to add using System.Configuration; explicitly.

string value1 = System.Configuration.ConfigurationManager.AppSettings["Value1"]

回答6:

sorry for late answer but may be my code may help u.

I placed 3 buttons on the winform surface. button1 & 2 will set different value and button3 will retrieve current value. so when run my code first add the reference System.configuration

and click on first button and then click on 3rd button to see what value has been set. next time again click on second & 3rd button to see again what value has been set after change.

so here is the code.

using System.Configuration;

 private void button1_Click(object sender, EventArgs e)
{
    Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
    config.AppSettings.Settings.Remove("DBServerName");
    config.AppSettings.Settings.Add("DBServerName", "FirstAddedValue1");
    config.Save(ConfigurationSaveMode.Modified);
}

private void button2_Click(object sender, EventArgs e)
{
    Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
    config.AppSettings.Settings.Remove("DBServerName");
    config.AppSettings.Settings.Add("DBServerName", "SecondAddedValue1");
    config.Save(ConfigurationSaveMode.Modified);
}

private void button3_Click(object sender, EventArgs e)
{
    Configuration config = ConfigurationManager.OpenExeConfiguration(Application.ExecutablePath);
          MessageBox.Show(config.AppSettings.Settings["DBServerName"].Value);
}

来源：https://stackoverflow.com/questions/925638/add-values-to-app-config-and-retrieve-them

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