Specifies the default value for an application settings property.
Namespace:
System.Configuration
Assembly:
System (in System.dll)
Visual Basic (Declaration)
<AttributeUsageAttribute(AttributeTargets.Property)> _
Public NotInheritable Class DefaultSettingValueAttribute _
Inherits Attribute
Dim instance As DefaultSettingValueAttribute
[AttributeUsageAttribute(AttributeTargets.Property)]
public sealed class DefaultSettingValueAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Property)]
public ref class DefaultSettingValueAttribute sealed : public Attribute
public final class DefaultSettingValueAttribute extends Attribute
Important Note: |
|---|
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: |
|---|
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. |
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;
}
}
};
System..::.Object
System..::.Attribute
System.Configuration..::.DefaultSettingValueAttribute
Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 3.5, 3.0, 2.0
Reference
Other Resources