ExpandableObjectConverter
Class
Definition
Provides a type converter to convert expandable objects to and from various other representations.
public class ExpandableObjectConverter : System.ComponentModel.TypeConverter
- Inheritance
- Derived
Inherited Members
System.ComponentModel.TypeConverter
System.Object
Examples
The following code example converts a variable of type Margins to a string variable.
String^ strM = "1,2,3,4";
System::Drawing::Printing::Margins^ m = gcnew System::Drawing::Printing::Margins( 1,2,3,4 );
Console::WriteLine( TypeDescriptor::GetConverter( strM )->CanConvertTo( System::Drawing::Printing::Margins::typeid ) );
Console::WriteLine( TypeDescriptor::GetConverter( m )->ConvertToString( m ) );
string strM="1,2,3,4";
System.Drawing.Printing.Margins m= new System.Drawing.Printing.Margins(1,2,3,4);
Console.WriteLine(TypeDescriptor.GetConverter(strM).CanConvertTo(typeof(System.Drawing.Printing.Margins)));
Console.WriteLine(TypeDescriptor.GetConverter(m).ConvertToString(m));
Dim strM As String
strM = "1,2,3,4"
Dim m As New System.Drawing.Printing.Margins(1, 2, 3, 4)
Console.WriteLine(TypeDescriptor.GetConverter(strM).CanConvertTo(GetType(System.Drawing.Printing.Margins)))
Console.WriteLine(TypeDescriptor.GetConverter(m).ConvertToString(m))
The following code example demonstrates how to use the NotifyParentPropertyAttribute and the ExpandableObjectConverter class to create an expandable property on a custom control. This code example is part of a larger example provided for the NotifyParentPropertyAttribute class.
[TypeConverter(typeof(BorderAppearanceConverter))]
public class BorderAppearance
{
private int borderSizeValue = 1;
private Color borderColorValue = Color.Empty;
[Browsable(true),
NotifyParentProperty(true),
EditorBrowsable(EditorBrowsableState.Always),
DefaultValue(1)]
public int BorderSize
{
get
{
return borderSizeValue;
}
set
{
if (value < 0)
{
throw new ArgumentOutOfRangeException(
"BorderSize",
value,
"must be >= 0");
}
if (borderSizeValue != value)
{
borderSizeValue = value;
}
}
}
[Browsable(true)]
[NotifyParentProperty(true)]
[EditorBrowsable(EditorBrowsableState.Always)]
[DefaultValue(typeof(Color), "")]
public Color BorderColor
{
get
{
return borderColorValue;
}
set
{
if (value.Equals(Color.Transparent))
{
throw new NotSupportedException("Transparent colors are not supported.");
}
if (borderColorValue != value)
{
borderColorValue = value;
}
}
}
}
<TypeConverter(GetType(BorderAppearanceConverter))> _
Public Class BorderAppearance
Private borderSizeValue As Integer = 1
Private borderColorValue As Color = Color.Empty
<Browsable(True), NotifyParentProperty(True), EditorBrowsable(EditorBrowsableState.Always), DefaultValue(1)> _
Public Property BorderSize() As Integer
Get
Return borderSizeValue
End Get
Set
If value < 0 Then
Throw New ArgumentOutOfRangeException("BorderSize", value, "must be >= 0")
End If
If borderSizeValue <> value Then
borderSizeValue = value
End If
End Set
End Property
<Browsable(True), NotifyParentProperty(True), EditorBrowsable(EditorBrowsableState.Always), DefaultValue(GetType(Color), "")> _
Public Property BorderColor() As Color
Get
Return borderColorValue
End Get
Set
If value.Equals(Color.Transparent) Then
Throw New NotSupportedException("Transparent colors are not supported.")
End If
If borderColorValue <> value Then
borderColorValue = value
End If
End Set
End Property
End Class
Remarks
This class adds support for properties on an object to the methods and properties provided by TypeConverter. To make a type of property expandable in the PropertyGrid, specify this TypeConverter for standard implementations of GetPropertiesSupported and GetProperties. Mark child properties with the NotifyParentPropertyAttribute to ensure correct behavior in a PropertyGrid control.
Note
You should never access a type converter directly. Instead, call the appropriate converter by using TypeDescriptor. For more information, see the examples in the TypeConverter base class.
For more information about type converters, see the TypeConverter base class and How to: Implement a Type Converter.
Constructors
| ExpandableObjectConverter() |
Initializes a new instance of the ExpandableObjectConverter class. |
Methods
| GetProperties(ITypeDescriptorContext, Object, Attribute[]) |
Gets a collection of properties for the type of object specified by the value parameter. |
| GetPropertiesSupported(ITypeDescriptorContext) |
Gets a value indicating whether this object supports properties using the specified context. |