Type.IsContextfulImpl 方法
实现 IsContextful 属性 (Property) 并确定 Type 在上下文中是否可以被承载。
**命名空间:**System
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
Protected Overridable Function IsContextfulImpl As Boolean
用法
Dim returnValue As Boolean
returnValue = Me.IsContextfulImpl
protected virtual bool IsContextfulImpl ()
protected:
virtual bool IsContextfulImpl ()
protected boolean IsContextfulImpl ()
protected function IsContextfulImpl () : boolean
返回值
如果 Type 能够在某个上下文中承载，则为 true；否则为 false。
备注
此方法可由派生类重写。
上下文截获对类成员的调用，并实施应用到类的策略（例如同步）。
示例
下面的示例说明 IsContextfulImpl 方法的用法。
Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic
Public Class MyTypeDelegatorClass
Inherits TypeDelegator
Public myElementType As String = Nothing
Private myType As Type = Nothing
Public Sub New(ByVal myType As Type)
MyBase.New(myType)
Me.myType = myType
End Sub 'New
' Override IsContextfulImpl.
Protected Overrides Function IsContextfulImpl() As Boolean
' Check whether the type is contextful.
If myType.IsContextful Then
myElementType = " is contextful "
Return True
End If
Return False
End Function 'IsContextfulImpl
End Class 'MyTypeDelegatorClass
Public Class MyTypeDemoClass
Public Shared Sub Main()
Try
Dim myType As MyTypeDelegatorClass
Console.WriteLine("Check whether MyContextBoundClass can be hosted in a context.")
' Check whether MyContextBoundClass is contextful.
myType = New MyTypeDelegatorClass(GetType(MyContextBoundClass))
If myType.IsContextful Then
Console.WriteLine(GetType(MyContextBoundClass).ToString() + " can be hosted in a context.")
Else
Console.WriteLine(GetType(MyContextBoundClass).ToString() + " cannot be hosted in a context.")
End If
' Check whether the int type is contextful.
myType = New MyTypeDelegatorClass(GetType(MyTypeDemoClass))
Console.WriteLine(ControlChars.NewLine + "Check whether MyTypeDemoClass can be hosted in a context.")
If myType.IsContextful Then
Console.WriteLine(GetType(MyTypeDemoClass).ToString() + " can be hosted in a context.")
Else
Console.WriteLine(GetType(MyTypeDemoClass).ToString() + " cannot be hosted in a context.")
End If
Catch e As Exception
Console.WriteLine("Exception: {0}", e.Message.ToString())
End Try
End Sub 'Main
End Class 'MyTypeDemoClass
' This class demonstrates the IsContextfulImpl method.
Public Class MyContextBoundClass
Inherits ContextBoundObject
Public myString As String = "This class is used to demonstrate members of the Type class."
End Class 'MyContextBoundClass
using System;
using System.Reflection;
public class MyTypeDelegatorClass : TypeDelegator
{
public string myElementType = null;
private Type myType = null ;
public MyTypeDelegatorClass(Type myType) : base(myType)
{
this.myType = myType;
}
// Override IsContextfulImpl.
protected override bool IsContextfulImpl()
{
// Check whether the type is contextful.
if(myType.IsContextful)
{
myElementType = " is contextful ";
return true;
}
return false;
}
}
public class MyTypeDemoClass
{
public static void Main()
{
try
{
MyTypeDelegatorClass myType;
Console.WriteLine ("Check whether MyContextBoundClass can be hosted in a context.");
// Check whether MyContextBoundClass is contextful.
myType = new MyTypeDelegatorClass(typeof(MyContextBoundClass));
if( myType.IsContextful)
{
Console.WriteLine(typeof(MyContextBoundClass) + " can be hosted in a context.");
}
else
{
Console.WriteLine(typeof(MyContextBoundClass) + " cannot be hosted in a context.");
}
// Check whether the int type is contextful.
myType = new MyTypeDelegatorClass(typeof(MyTypeDemoClass));
Console.WriteLine ("\nCheck whether MyTypeDemoClass can be hosted in a context.");
if( myType.IsContextful)
{
Console.WriteLine(typeof(MyTypeDemoClass) + " can be hosted in a context.");
}
else
{
Console.WriteLine(typeof(MyTypeDemoClass) + " cannot be hosted in a context.");
}
}
catch( Exception e )
{
Console.WriteLine("Exception: {0}", e.Message);
}
}
}
// This class demonstrates IsContextfulImpl.
public class MyContextBoundClass : ContextBoundObject
{
public string myString = "This class is used to demonstrate members of the Type class.";
}
using namespace System;
using namespace System::Reflection;
public ref class MyTypeDelegatorClass: public TypeDelegator
{
public:
String^ myElementType;
private:
Type^ myType;
public:
MyTypeDelegatorClass( Type^ myType )
: TypeDelegator( myType )
{
this->myType = myType;
}
protected:
// Override IsContextfulImpl.
virtual bool IsContextfulImpl() override
{
// Check whether the type is contextful.
if ( myType->IsContextful )
{
myElementType = " is contextful ";
return true;
}
return false;
}
};
public ref class MyTypeDemoClass{};
// This class demonstrates IsContextfulImpl.
public ref class MyContextBoundClass: public ContextBoundObject
{
public:
String^ myString;
};
int main()
{
try
{
MyTypeDelegatorClass^ myType;
Console::WriteLine( "Check whether MyContextBoundClass can be hosted in a context." );
// Check whether MyContextBoundClass is contextful.
myType = gcnew MyTypeDelegatorClass( MyContextBoundClass::typeid );
if ( myType->IsContextful )
{
Console::WriteLine( "{0} can be hosted in a context.", MyContextBoundClass::typeid );
}
else
{
Console::WriteLine( "{0} cannot be hosted in a context.", MyContextBoundClass::typeid );
}
myType = gcnew MyTypeDelegatorClass( MyTypeDemoClass::typeid );
Console::WriteLine( "\nCheck whether MyTypeDemoClass can be hosted in a context." );
if ( myType->IsContextful )
{
Console::WriteLine( "{0} can be hosted in a context.", MyTypeDemoClass::typeid );
}
else
{
Console::WriteLine( "{0} cannot be hosted in a context.", MyTypeDemoClass::typeid );
}
}
catch ( Exception^ e )
{
Console::WriteLine( "Exception: {0}", e->Message );
}
}
import System.*;
import System.Reflection.*;
public class MyTypeDelegatorClass extends TypeDelegator
{
public String myElementType = null;
private Type myType = null;
public MyTypeDelegatorClass(Type myType)
{
super(myType);
this.myType = myType;
} //MyTypeDelegatorClass
// Override IsContextfulImpl.
protected boolean IsContextfulImpl()
{
// Check whether the type is contextful.
if (myType.get_IsContextful()) {
myElementType = " is contextful ";
return true;
}
return false;
} //IsContextfulImpl
} //MyTypeDelegatorClass
public class MyTypeDemoClass
{
public static void main(String[] args)
{
try {
MyTypeDelegatorClass myType;
Console.WriteLine("Check whether MyContextBoundClass can be hosted"
+ " in a context.");
// Check whether MyContextBoundClass is contextful.
myType = new MyTypeDelegatorClass(MyContextBoundClass.class.ToType());
if (myType.get_IsContextful()) {
Console.WriteLine(MyContextBoundClass.class.ToType()
+ " can be hosted in a context.");
}
else {
Console.WriteLine(MyContextBoundClass.class.ToType()
+ " cannot be hosted in a context.");
}
// Check whether the int type is contextful.
myType = new MyTypeDelegatorClass(MyTypeDemoClass.class.ToType());
Console.WriteLine("\nCheck whether MyTypeDemoClass can be hosted"
+ " in a context.");
if (myType.get_IsContextful()) {
Console.WriteLine(MyTypeDemoClass.class.ToType()
+ " can be hosted in a context.");
}
else {
Console.WriteLine(MyTypeDemoClass.class.ToType()
+ " cannot be hosted in a context.");
}
}
catch (System.Exception e) {
Console.WriteLine("Exception: {0}", e.get_Message());
}
} //main
} //MyTypeDemoClass
// This class demonstrates IsContextfulImpl.
public class MyContextBoundClass extends ContextBoundObject
{
public String myString = "This class is used to demonstrate members of the"
+ " Type class.";
} //MyContextBoundClass
平台
Windows 98、Windows 2000 SP4、Windows Millennium Edition、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition
.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。
版本信息
.NET Framework
受以下版本支持：2.0、1.1、1.0