Please help with generic types

Question

probably something for you guys.

Basically I got a method that deserialize an XML file, my problem is that I want to use this method for different XML files and place them in the appropriate class.so I got 2 classes.

1) MainSettings class  = mainSettings.xml file

2) MapSettings class = mapSettings.xml file

I declared the method as a generic because I send in the constructor the different type 1) MainSettings  2) MapSettings

I call the method this way

MainSettings _MainSettings = new MainSettings();

initialize("mySettings.xml", ApplicationData.Current.LocalFolder, _MainSettings);

here is the deserialization method

//Read the XML file and put in the Setting class
        public async void initialize<T>(string fileName, StorageFolder folder, T tSettingsClass)
        {
            try
            {
               var statesFile = await folder.GetFileAsync(fileName);

               //Deserialize xml data to object
               XmlSerializer xs = new XmlSerializer(tSettingsClass.GetType()); 
               using (Stream stream = await statesFile.OpenStreamForReadAsync())
               {
                  //problem here. instead of_MainSettings and MainSettings 
                  //I want to use the generic type clsss
                  _MainSettings = xs.Deserialize(stream) as MainSettings;
               }
            }
            catch (FileNotFoundException)
            {
                //CreateTheSettingsFile();

            }
        }

Hope I explained myself correctly.

Thank you

Answer 1

public async Task<T> GetSettings<T>(string fileName, StorageFolder folder) where T : class
        {

            T settings = default(T);
            try
            {
                var statesFile = await folder.GetFileAsync(fileName);

                XmlSerializer xs = new XmlSerializer(typeof(T));
                using (Stream stream = await statesFile.OpenStreamForReadAsync())
                {
                    settings = xs.Deserialize(stream) as T;
                }
            }
            catch (FileNotFoundException)
            {
                //CreateTheSettingsFile();
            }
            return settings;
        }

Also, you can change return type to "void" and set settings in this method. But in this case you need to check what type you initialize (if(settings) is MapSettings) etc). I recommend you to return settings from method, not initialize in inside it.

Answer 2

That worked great.

Here is some reading Material about Constraints on type Parameters

http://msdn.microsoft.com/en-us/library/d5x73970.aspx