Class Preference

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Definition

Namespace:
Tizen.Applications
Assembly:
Tizen.Applications.Preference.dll

The Preference class provides methods to store and retrieve application specific data/preferences. Preferences are stored in the form of key-value pairs. Key names must be text strings while values can be integers, doubles, strings, or booleans.


                
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public static class Preference
Inheritance
object
Preference

Properties

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Keys

Retrieves all keys of the application preferences.

Declaration

                
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public static IEnumerable<string> Keys { get; }
Property Value
Type Description
System.Collections.Generic.IEnumerable<T><string>

The list of keys.
Examples

                

                

                    
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    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);
    }

Methods

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Contains(string)

Checks whether the given key exists in the preference.

Declaration

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

The name of the key to check.
Returns
Type Description
bool

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

This method checks if the specified key exists in the preferences. It returns true if the key exists, and false if not. The key argument should be a valid parameter. An ArgumentException will be thrown if the key is invalid. Additionally, an IOException may be thrown if the method fails due to an internal input/output error.

Examples

                

                

                    
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    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
System.ArgumentException

Thrown if the key is an invalid parameter.
System.IO.IOException

Thrown when the method failed due to an internal I/O error.
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Get<T>(string)

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

Declaration

                
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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

                

                

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

Thrown if the key is not found.
System.ArgumentException

Thrown if the key is an invalid parameter.
System.IO.IOException

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

GetEventContext(string)

Gets the event context for the given key.

Declaration

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

The preference key.
Returns
Type Description
System.WeakReference<T><Preference.EventContext>

The event context of respective key.
Examples

                

                

                    
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    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
System.Collections.Generic.KeyNotFoundException

Thrown if the key is not found.
System.ArgumentException

Thrown if the key is invalid parameter.
See Also
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Remove(string)

Removes any preference value with the given key.

Declaration

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

The key to remove.
Examples

                

                

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

Thrown if the key is not found.
System.IO.IOException

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

RemoveAll()

Removes all the key-value pairs from the preference.

Declaration

                
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public static void RemoveAll()
Examples

                

                

                    
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    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
System.IO.IOException

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

Set(string, object)

Sets a key-value pair representing the preference.

Declaration

                
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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. Supported value data types include integers, doubles, strings, and booleans.

Examples

                

                

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

Thrown if the key is an invalid parameter.
System.IO.IOException

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