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c#visual-studiosettings
Calanus
Calanus

Reputation: 26277

How do I save/serialize a custom class to the settings file?

I have a small class that holds two strings as follows:

    public class ReportType
    {
        private string displayName;
        public string DisplayName
        {
            get { return displayName; }
        }

        private string reportName;
        public string ReportName
        {
            get { return reportName; }
        }

        public ReportType(string displayName, string reportName)
        {
            this.displayName = displayName;
            this.reportName = reportName;
        }
    }

I want to save an instance of this class to my settings file so that I can do the following:

ReportType reportType = Settings.Default.SelectedReportType;

Googling seems to suggest that it is possible but there doesn't appear to be a clear guide anywhere for me to follow. I understand that some serialization is required but don't really know where to begin. Also, when I go into the Settings screen in Visual Studio and click "browse" under the Type column there is no option to select the current namespace which contains the ReportType class.

Upvotes: 24

Views: 28978

Answers (5)

gcode
gcode

Reputation: 2989

I want to add in my own solution after having difficulty with the others. There's no need to do anything super special to get a custom class/Type with properties to show up in the Select a Type dialog box, and be serialized correctly by the .Net Application Settings system.

Create a Type/Class

Create a class as the original poster has, but be aware of two important details:

  • The class must be public, and contain a constructor without any parameters, to act as the default state of the class. I can't find any official documentation on this, but it has been my experience that this is required for successful serialization and recogniztion by the Select a Type dialog box.
  • The class must be contained in an assembly outside of the current assembly you are defining the Application Setting in (see here.) You can work around this and other quirks of the Designer by defining the Settings by code.

Prepare the Designer

In order for the new Type to be displayed in the Designer correctly, you need to first build your solution, then close the solution. Now reopen it, and your Type will now be browsable in the Settings designer.

This will be enough for .Net to be able to serialize your Type either directly to a string if possible, or to plain XML.

Advanced Serialization Control

You can also exercise advanced control over how your custom Type class is serialized without much extra code or overriding the base Settings class.

The LocalFileSettingsProvider (default used by Project Settings Designer) has a defined logic for how it attempts to serialize Settings properties. If you define a TypeConverter for your Type, then it will follow that - otherwise, it follows Xml Serialization rules. This means you can use Xml property attributes throughout your class to control how it is serialized to a file. For example, if you want to exclude certain properties entirely, you can hide them by making them private.

Upvotes: 0

Guy
Guy

Reputation: 1360

@Calanus solution did not work for me as-is (on Visual Studio 2015). The missing step is actually setting or getting from the actual settings. As for the original question, implementing a simple POCO can be achieved like this:

[Serializable]
public class ReportType
{
    public string DisplayName { get; set; }
    public string ReportName { get; set; }

    public ReportType() { }

    public ReportType(string displayName, string reportName)
    {
        DisplayName = displayName;
        ReportName = reportName;
    }
}

// the class responsible for reading and writing the settings
public sealed class ReportTypeSettings : ApplicationSettingsBase
{
    [UserScopedSetting]
    [SettingsSerializeAs(SettingsSerializeAs.Xml)]
    [DefaultSettingValue("")]
    public ReportType ReportType
    {
        get { return (ReportType)this[nameof(ReportType)]; }
        set { this[nameof(ReportType)] = value; }
    }
}

I have used for actually serialization a list:

[Serializable]
public class Schedule
{
    public Schedule() : this(string.Empty, DateTime.MaxValue)
    {
    }

    public Schedule(string path, DateTime terminationTime)
    {
        path = driverPath;
        TerminationTime = terminationTime;
    }

    public DateTime TerminationTime { get; set; }
    public string Path { get; set; }
}

public sealed class Schedules : ApplicationSettingsBase
{
    [UserScopedSetting]
    [SettingsSerializeAs(SettingsSerializeAs.Xml)]
    [DefaultSettingValue("")]
    public List<Schedule> Entries
    {
        get { return (List<Schedule>)this[nameof(Entries)]; }
        set { this[nameof(Entries)] = value; }
    }
}

Instantiate a Schedules (ReportTypeSettings) object. It will automatically read the settings. You can use Reload method to refresh. For instance:

ReportTypeSettings rts = new ReportTypeSettings();
rts.Reload();
rts.ReportType = new ReportType("report!", "report1");
rts.Save();

IMPORTANT NOTES:

  1. Note that UserScoped is intentionally used. ApplicationScoped behaves differently, so make sure you know what you are doing.
  2. The members are public (including the setter), and there's a default constructor even though it was needed by the code. However, serialization using XML didn't work properly. Due to time constraints I didn't investigate.
  3. You can change serialization to binary format as well. It will use BASE64 to store the data.
  4. All the settings is stored in LOCAL APP DATA folder, in a text file.

Upvotes: 4

Calanus
Calanus

Reputation: 26277

OK I think that I have eventually worked it out. The first thing to do is to add the following attributes to each property of the ReportType class that needs to be serialised and inherit the class from ApplicationSettingsBase:

    public class ReportType : ApplicationSettingsBase
    {
        private string displayName;
        [UserScopedSetting()]
        [SettingsSerializeAs(System.Configuration.SettingsSerializeAs.Xml)]
        public string DisplayName
        {
            get { return displayName; }
        }

..............

and then, once you have rebuilt your assembly (important!) you can go into the settings screen and click browse and then type your namespace and class name in the text box at the bottom (e.g. Label_Creator.ReportType). The namespace and class name do not appear in the tree and so this part is not exactly obvious what you need to do which is why it is a bit confusing....

Upvotes: 19

abatishchev
abatishchev

Reputation: 100248

Just a bit more clear code then Charlie's

public class ReportType
{
  public static ReportType CreateDefaults()
  {
    return new ReportType
    {
       DisplayName =  ConfigurationManager.AppSettings["DefaultDisplayName"],
       ReportName = ConfigurationManager.AppSettings["DefaultReportName"]
    };
  }
}

Upvotes: 3

Charlie
Charlie

Reputation: 10307

How about creating a static method which returns an instance of ReportType containing data from the config file. It's simpler and I don't think serializing is necessary.

public class ReportType
{
  public static ReportType GetDefaultSelectedReportType()
  {
    string displayName = ConfigurationManager.AppSettings["DefaultDisplayName"];
    string reportName = ConfigurationManager.AppSettings["DefaultReportName"];
    return new ReportType(displayName, reportName);
  }
  .
  .
  .
}

Upvotes: 2

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