.NET Framework Class Library
DefaultSettingValueAttribute Class

Specifies the default value for an application settings property.

Inheritance Hierarchy
SystemObject
   SystemAttribute
    System.ConfigurationDefaultSettingValueAttribute

Namespace:   System.Configuration
Assembly:  System (in System.dll)
Syntax
<[%$TOPIC/09kwb831_en-us_VS_110_2_0_0_0_0%]([%$TOPIC/09kwb831_en-us_VS_110_2_0_0_0_1%].Property)> _
Public NotInheritable Class DefaultSettingValueAttribute _
	Inherits [%$TOPIC/09kwb831_en-us_VS_110_2_0_0_0_2%]
[[%$TOPIC/09kwb831_en-us_VS_110_2_0_1_0_0%]([%$TOPIC/09kwb831_en-us_VS_110_2_0_1_0_1%].Property)]
public sealed class DefaultSettingValueAttribute : [%$TOPIC/09kwb831_en-us_VS_110_2_0_1_0_2%]
[[%$TOPIC/09kwb831_en-us_VS_110_2_0_2_0_0%]([%$TOPIC/09kwb831_en-us_VS_110_2_0_2_0_1%]::Property)]
public ref class DefaultSettingValueAttribute sealed : public [%$TOPIC/09kwb831_en-us_VS_110_2_0_2_0_2%]
[<[%$TOPIC/09kwb831_en-us_VS_110_2_0_3_0_0%]>]
[<[%$TOPIC/09kwb831_en-us_VS_110_2_0_3_0_1%]([%$TOPIC/09kwb831_en-us_VS_110_2_0_3_0_2%].Property)>]
type DefaultSettingValueAttribute =  
    class 
        inherit [%$TOPIC/09kwb831_en-us_VS_110_2_0_3_0_3%] 
    end

The DefaultSettingValueAttribute type exposes the following members.

Constructors
  NameDescription
Public method DefaultSettingValueAttributeInitializes an instance of the DefaultSettingValueAttribute class.
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Properties
  NameDescription
Public property TypeIdWhen implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)
Public property ValueGets the default value for the application settings property.
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Methods
  NameDescription
Public method EqualsInfrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
Public method GetHashCodeReturns the hash code for this instance. (Inherited from Attribute.)
Public method GetTypeGets the Type of the current instance. (Inherited from Object.)
Public method IsDefaultAttributeWhen overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
Public method MatchWhen overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Public method ToStringReturns a string that represents the current object. (Inherited from Object.)
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Explicit Interface Implementations
  NameDescription
Explicit interface implemetation Private method _AttributeGetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeGetTypeInfoRetrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeGetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetation Private method _AttributeInvokeProvides access to properties and methods exposed by an object. (Inherited from Attribute.)
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Remarks
Important noteImportant

DefaultSettingValueAttribute can only be applied to individual settings properties; it is invalid to apply this attribute to an entire application settings class.

Different settings providers may have different requirements or limitations on the use of the DefaultSettingValueAttribute. For example, the LocalFileSettingsProvider does not require this attribute, and will override any value provided by this attribute if there are any values—default or user-modified— already present in the data store.

DefaultSettingValueAttribute requires that the default value can be represented as a string. As a result, settings using XML serialization cannot have a default value specified by means of this attribute. Some providers may choose to support multiple serialization schemes which can be specified at compile time using the SettingsSerializeAsAttribute.

Caution noteCaution

The default values specified by this attribute are stored as plain text in the resultant compiled .exe or .dll file. Therefore these default values are inherently insecure.

Examples

The following code example demonstrates the use of the DefaultSettingValueAttribute applied to three of the four properties of the FormSettings wrapper class, which is derived from the ApplicationSettingsBase class. This class is used to persist the location, size, background color, and text of form. The first three of these form properties have default values associated with them.

The full code example is listed in the ApplicationSettingsBase class overview.

'Application settings wrapper class. This class defines the settings we intend to use in our application. 
NotInheritable Class FormSettings
    Inherits ApplicationSettingsBase

    <UserScopedSettingAttribute()> _
    Public Property FormText() As String 
        Get 
            Return CStr(Me("FormText"))
        End Get 
        Set(ByVal value As String)
            Me("FormText") = value
        End Set 
    End Property

    <UserScopedSettingAttribute(), DefaultSettingValueAttribute("0, 0")> _
    Public Property FormLocation() As Point
        Get 
            Return CType(Me("FormLocation"), Point)
        End Get 
        Set(ByVal value As Point)
            Me("FormLocation") = value
        End Set 
    End Property

    <UserScopedSettingAttribute(), DefaultSettingValueAttribute("225, 200")> _
    Public Property FormSize() As Size
        Get 
            Return CType(Me("FormSize"), Size)
        End Get 
        Set(ByVal value As Size)
            Me("FormSize") = value
        End Set 
    End Property

    <UserScopedSettingAttribute(), DefaultSettingValueAttribute("LightGray")> _
    Public Property FormBackColor() As Color
        Get 
            Return CType(Me("FormBackColor"), Color)
        End Get 
        Set(ByVal value As Color)
            Me("FormBackColor") = value
        End Set 
    End Property 
End Class
//Application settings wrapper class 
sealed class FormSettings : ApplicationSettingsBase
{
    [UserScopedSettingAttribute()]
    public String FormText
    {
        get { return (String)this["FormText"]; }
        set { this["FormText"] = value; }
    }

    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("0, 0")]
    public Point FormLocation
    {
        get { return (Point)(this["FormLocation"]); }
        set { this["FormLocation"] = value; }
    }

    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("225, 200")]
    public Size FormSize
    {
        get { return (Size)this["FormSize"]; }
        set { this["FormSize"] = value; }
    }


    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("LightGray")]
    public Color FormBackColor
    {
        get { return (Color)this["FormBackColor"]; }
        set { this["FormBackColor"] = value; }
    }

}
//Application settings wrapper class 
ref class FormSettings sealed: public ApplicationSettingsBase
{
public:
    [UserScopedSettingAttribute()]
    property String^ FormText
    {
        String^ get()
        {
            return (String^)this["FormText"];
        }
        void set( String^ value )
        {
            this["FormText"] = value;
        }
    }

public:
    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("0, 0")]
    property Point FormLocation
    {
        Point get()
        {
            return (Point)(this["FormLocation"]);
        }
        void set( Point value )
        {
            this["FormLocation"] = value;
        }
    }

public:
    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("225, 200")]
    property Size FormSize
    {
        Size get()
        {
            return (Size)this["FormSize"];
        }
        void set( Size value )
        {
            this["FormSize"] = value;
        }
    }

public:
    [UserScopedSettingAttribute()]
    [DefaultSettingValueAttribute("LightGray")]
    property Color FormBackColor
    {
        Color get()
        {
            return (Color)this["FormBackColor"];
        }
        void set(Color value)
        {
            this["FormBackColor"] = value;
        }
    }

};
Version Information

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Platforms

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Thread Safety
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.