ExpandableObjectConverter 类
定义
重要
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提供一个类型转换器，用于将可扩展对象与各种其他表示形式相互转换。
public ref class ExpandableObjectConverter : System::ComponentModel::TypeConverterpublic class ExpandableObjectConverter : System.ComponentModel.TypeConvertertype ExpandableObjectConverter = class
inherit TypeConverterPublic Class ExpandableObjectConverter
Inherits TypeConverter- 继承
- 派生
示例
下面的代码示例将类型的 Margins 变量转换为字符串变量。
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(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))
下面的代码示例演示如何使用 NotifyParentPropertyAttribute 和 ExpandableObjectConverter 类在自定义控件上创建可扩展属性。 该代码示例是 NotifyParentPropertyAttribute 类中的一个较大示例的一部分。
[TypeConverter(typeof(BorderAppearanceConverter))]
public class BorderAppearance
{
int borderSizeValue = 1;
Color borderColorValue = Color.Empty;
[Browsable(true),
NotifyParentProperty(true),
EditorBrowsable(EditorBrowsableState.Always),
DefaultValue(1)]
public int BorderSize
{
get => 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 => 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
注解
此类将对象上的属性支持添加到方法提供的属性和属性。TypeConverter 若要使一种类型的属性可PropertyGrid展开，请为标准实现GetPropertiesSupported和GetProperties指定此属性TypeConverter。 使用
注释
不应直接访问类型转换器。 请改用 <
有关类型转换器的详细信息，请参阅 TypeConverter 基类。
构造函数
| 名称 | 说明 |
|---|---|
| ExpandableObjectConverter() |
初始化 ExpandableObjectConverter 类的新实例。 |
