Create new settings on runtime and read after restart

问题

I would like to store usersettings. They are created at runtime and should be read after restarting the application.

private void MainForm_FormClosing(object sender, FormClosingEventArgs e)
{
    var property = new SettingsProperty("Testname");
    property.DefaultValue = "TestValue";
    Settings.Default.Properties.Add(property);
    Settings.Default.Save();
}

At this point, the setting is stored and I can access it.

After restarting the application, the newly created setting is away:

public MainForm()
{
    InitializeComponent();

    foreach (SettingsProperty property in Settings.Default.Properties)
    {
          //Setting which was created on runtime before not existing
    }
}

Trying this piece: Settings.Default.Reload(); didn't affect anything on the outcome. I tried also other things like described here, but neither of them worked for me.

回答1:

Probably a bit late for you but for others there are 2 parts.

Saving the new UserSetting
Reloading from userConfig.xml at startup

I created this extension for ApplicationSettingsBase based on other answers

public static void Add<T>(this ApplicationSettingsBase settings, string propertyName, T val)
{           
    var p = new SettingsProperty(propertyName)
    {
        PropertyType = typeof(T),
        Provider = settings.Providers["LocalFileSettingsProvider"],
        SerializeAs = SettingsSerializeAs.Xml
    };

    p.Attributes.Add(typeof(UserScopedSettingAttribute), new UserScopedSettingAttribute());

    settings.Properties.Add(p);
    settings.Reload();

    //finally set value with new value if none was loaded from userConfig.xml
    var item = settings[propertyName];
    if (item == null)
    {
        settings[propertyName] = val;
        settings.Save();
    }
}

This will make Settings["MyKey"] work, but when you restart the setting will not be loaded, but the userConfig.xml has the new value (if you called Settings.Save())

The trick to get it to reload is to execute Add again e.g

if (settings.Properties.Cast<SettingsProperty>().All(s => s.Name != propertyName))
{
    settings.Add("MyKey", 0);
};

The way Add works is that it will only set MyKey to 0 if no value is loaded from userConfig.xml

来源：https://stackoverflow.com/questions/26018606/create-new-settings-on-runtime-and-read-after-restart

标签

winforms

settings