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    Class Preference

    Definition

    Namespace:
    Tizen.Applications
    Assembly:
    Tizen.Applications.Preference.dll
    API Level:
    3

    The preference class provides APIs to store and retrieve an application specific data/preference. A preference is saved in the form of a key-value pair. Keys are always text strings and the value can be any one of the four types: integer, double, string, and boolean.

    public static class Preference
    Inheritance
    Object
    Preference

    Properties

    View Source

    Keys

    Retrieves all keys of the application preferences.

    Declaration
    public static IEnumerable<string> Keys { get; }
    Property Value
    Type Description
    IEnumerable<String>

    The list of keys.

    Examples
        Preference.Set("Option_enabled", true);
        Preference.Set("active_user", "Joe");
        Preference.Set("default_volume", 10);
        Preference.Set("brightness", "0.6");
        foreach(string key in Preference.Keys)
        {
            Console.WriteLine("key {0}", key);
        }
    API Level: 3

    Methods

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    Contains(String)

    Checks whether the given key exists in the preference.

    Declaration
    public static bool Contains(string key)
    Parameters
    Type Name Description
    String key

    The name of the key to check.

    Returns
    Type Description
    Boolean

    True if the key exists in the preference, otherwise false.

    Examples
        Preference.Set("active_user", "Joe");
        bool exists = Preference.Contains("active_user");
        if (exists)
        {
            string value = Preference.Get<istring>("active_user");
            Console.WriteLine("user {0}", value);
        }
    Exceptions
    Type Condition
    ArgumentException

    Thrown if the key is an invalid parameter.

    IOException

    Thrown when the method failed due to an internal I/O error.

    API Level: 3
    View Source

    Get<T>(String)

    Gets the value of a preference item with the specified key. Note that this is a generic method.

    Declaration
    public static T Get<T>(string key)
    Parameters
    Type Name Description
    String key

    The key of the preference.

    Returns
    Type Description
    T

    The value of the preference item if it is of the specified generic type.

    Type Parameters
    Name Description
    T

    The generic type to return.

    Examples
        bool exists = Preference.Contains("active_user");
        if (exists)
        {
            string value = Preference.Get<string>("active_user");
            Console.WriteLine("user {0}", value);
        }
    Exceptions
    Type Condition
    KeyNotFoundException

    Thrown if the key is not found.

    ArgumentException

    Thrown if the key is an invalid parameter.

    IOException

    Thrown when the method failed due to an internal I/O error.

    API Level: 3
    View Source

    GetEventContext(String)

    Gets the event context for the given key.

    Declaration
    public static WeakReference<Preference.EventContext> GetEventContext(string key)
    Parameters
    Type Name Description
    String key

    The preference key.

    Returns
    Type Description
    WeakReference<Preference.EventContext>

    The event context of respective key.

    Examples
        private static void Preference_PreferenceChanged(object sender, PreferenceChangedEventArgs e)
        {
            Console.WriteLine("key {0}", e.Key);
        }
    
        Preference.EventContext context = null;
        Preference.GetEventContext("active_user").TryGetTarget(out context);
        if(context != null)
        {
            context.Changed += Preference_PreferenceChanged;
        }
    
        Preference.Set("active_user", "Poe");
    
        Preference.GetEventContext("active_user").TryGetTarget(out context);
        if (context != null)
        {
            context.Changed -= Preference_PreferenceChanged;
        }
    Exceptions
    Type Condition
    KeyNotFoundException

    Thrown if the key is not found.

    ArgumentException

    Thrown if the key is invalid parameter.

    See Also
    Preference.EventContext
    API Level: 3
    View Source

    Remove(String)

    Removes any preference value with the given key.

    Declaration
    public static void Remove(string key)
    Parameters
    Type Name Description
    String key

    The key to remove.

    Examples
        bool exists = Preference.Contains("active_user");
        if (exists)
        {
            string value = Preference.Remove("active_user");
        }
    Exceptions
    Type Condition
    KeyNotFoundException

    Thrown if the key is not found.

    IOException

    Thrown when the method failed due to an internal I/O error.

    API Level: 3
    View Source

    RemoveAll()

    Removes all the key-value pairs from the preference.

    Declaration
    public static void RemoveAll()
    Examples
        Preference.Set("Option_enabled", true);
        Preference.Set("active_user", "Joe");
        Preference.Set("default_volume", 10);
        Preference.Set("brightness", "0.6");
        Preference.RemoveAll();
    Exceptions
    Type Condition
    IOException

    Thrown when the method failed due to an internal I/O error.

    API Level: 3
    View Source

    Set(String, Object)

    Sets a key-value pair representing the preference.

    Declaration
    public static void Set(string key, object value)
    Parameters
    Type Name Description
    String key

    The name of the key to create/modify.

    Object value

    The value corresponding to the key.

    Remarks

    If the key already exists in the preference, the old value will be overwritten with a new value. Data types for supported values are: integer, double, string, and bool.

    Examples
        Preference.Set("Option_enabled", true);
        Preference.Set("active_user", "Joe");
        Preference.Set("default_volume", 10);
        Preference.Set("brightness", "0.6");
    Exceptions
    Type Condition
    ArgumentException

    Thrown if the key is an invalid parameter.

    IOException

    Thrown when the method failed due to an internal I/O error.

    API Level: 3
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