MethodBase.IsHideBySig 属性
获取一个值，该值指示是否只有一个签名完全相同的同一种类的成员在派生类中是隐藏的。
**命名空间:**System.Reflection
**程序集:**mscorlib（在 mscorlib.dll 中）
语法
声明
Public ReadOnly Property IsHideBySig As Boolean
用法
Dim instance As MethodBase
Dim value As Boolean
value = instance.IsHideBySig
public bool IsHideBySig { get; }
public:
virtual property bool IsHideBySig {
bool get () sealed;
}
/** @property */
public final boolean get_IsHideBySig ()
public final function get IsHideBySig () : boolean
属性值
如果此成员被签名隐藏，则为 true；否则为 false。
备注
如果派生类的成员是通过 C# new 修饰符或 Visual Basic Shadows 修饰符声明的，则该成员可以隐藏基类的同名成员。C# 通过签名隐藏基类成员。即，如果基类成员有多个重载，则唯一被隐藏的是具有相同签名的成员。与此相反，Visual Basic 隐藏所有基类重载。因此，对于用 Visual Basic Shadows 修饰符声明的成员，IsHideBySig 返回 false；对于用 C# new 修饰符声明的成员，则返回 true。
示例
下面的代码示例包含具有一个重载方法的基类和隐藏了其中一个重载的派生类。在代码示例的 Visual Basic 版本中，对于派生类的成员，IsHideBySig 属性返回 false。在代码示例的 C# 版本中，对于派生类的成员，该属性返回 true。
Imports System
Imports System.Reflection
' The base class B contains an overloaded method M.
'
Public Class B
Public Overridable Sub M()
Console.WriteLine("B's M()")
End Sub
Public Overridable Sub M(ByVal x As Integer)
Console.WriteLine("B's M({0})", x)
End Sub
End Class
' The derived class D hides the inherited method M.
'
Public Class D
Inherits B
Shadows Public Sub M(ByVal i As Integer)
Console.WriteLine("D's M({0})", i)
End Sub
End Class
Public Class Test
Public Shared Sub Main()
Dim dinst As New D()
' In Visual Basic, the method in the derived class hides by
' name, rather than by signature. Thus, although a list of all the
' overloads of M shows three overloads, only one can be called from
' class D.
'
Console.WriteLine("------ List the overloads of M in the derived class D ------")
Dim t As Type = dinst.GetType()
For Each minfo As MethodInfo In t.GetMethods()
If minfo.Name = "M" Then Console.WriteLine( _
"Overload of M: {0} IsHideBySig = {1}, DeclaringType = {2}", _
minfo, minfo.IsHideBySig, minfo.DeclaringType)
Next
' The method M in the derived class hides the method in B.
'
Console.WriteLine("------ Call the overloads of M available in D ------")
' The following line causes a compile error, because both overloads
' in the base class are hidden. Contrast this with C#, where only
' one of the overloads of B would be hidden.
'dinst.M()
dinst.M(42)
' If D is cast to the base type B, both overloads of the
' shadowed method can be called.
'
Console.WriteLine("------ Call the shadowed overloads of M ------")
Dim binst As B = dinst
binst.M()
binst.M(42)
End Sub 'Main
End Class 'Test
' This code example produces the following output:
' ------ List the overloads of M in the derived class D ------
' Overload of M: Void M(Int32) IsHideBySig = False, DeclaringType = B
' Overload of M: Void M() IsHideBySig = False, DeclaringType = B
' Overload of M: Void M(Int32) IsHideBySig = False, DeclaringType = D
' ------ Call the overloads of M available in D ------
' D's M(42)
' ------ Call the shadowed overloads of M ------
' B's M()
' B's M(42)
using System;
using System.Reflection;
// The base class B contains an overloaded method M.
//
public class B
{
public virtual void M()
{
Console.WriteLine("B's M()");
}
public virtual void M(int x)
{
Console.WriteLine("B's M({0})", x);
}
}
// The derived class D hides one overload of the inherited
// method M.
//
public class D:
B
{
new public void M(int i)
{
Console.WriteLine("D's M({0})", i);
}
}
public class Test
{
public static void Main()
{
D dinst = new D();
// In C#, the method in the derived class hides by name and by
// signature, so the overload in the derived class hides only one
// of the overloads in the base class.
//
Console.WriteLine("------ List the overloads of M in the derived class D ------");
Type t = dinst.GetType();
foreach( MethodInfo minfo in t.GetMethods() )
{
if (minfo.Name=="M") {Console.WriteLine("Overload of M: {0} IsHideBySig = {1}, DeclaringType = {2}", minfo, minfo.IsHideBySig, minfo.DeclaringType);}
}
// The method M in the derived class hides one overload of the
// method in B. Contrast this with Visual Basic, which hides by
// name instead of by name and signature. In Visual Basic, the
// parameterless overload of M would be unavailable from D.
//
Console.WriteLine("------ Call the overloads of M available in D ------");
dinst.M();
dinst.M(42);
// If D is cast to the base type B, both overloads of the
// shadowed method can be called.
//
Console.WriteLine("------ Call the shadowed overloads of M ------");
B binst = dinst;
binst.M();
binst.M(42);
} //Main
} //Test
/* This code example produces the following output:
------ List the overloads of M in the derived class D ------
Overload of M: Void M(Int32) IsHideBySig = True, DeclaringType = B
Overload of M: Void M() IsHideBySig = True, DeclaringType = B
Overload of M: Void M(Int32) IsHideBySig = True, DeclaringType = D
------ Call the overloads of M available in D ------
B's M()
D's M(42)
------ Call the shadowed overloads of M ------
B's M()
B's M(42)
*/
using namespace System;
using namespace System::Reflection;
// The base class Parent contains an overloaded method PrintCall.
//
public ref class Parent
{
public:
virtual void PrintCall()
{
Console::WriteLine("Parent's PrintCall()");
}
public:
virtual void PrintCall(int x)
{
Console::WriteLine("Parent's PrintCall({0})", x);
}
};
// The derived class Child hides one overload of the inherited
// method PrintCall.
//
public ref class Child : public Parent
{
public:
void PrintCall(int i) new
{
Console::WriteLine("Child's PrintCall({0})", i);
}
};
int main()
{
Child^ childInstance = gcnew Child();
// In C#, the method in the derived class hides by name and by
// signature, so the overload in the derived class hides only one
// of the overloads in the base class.
//
Console::WriteLine("------ List the overloads of PrintCall in the " +
"derived class Child ------");
Type^ t = childInstance->GetType();
for each(MethodInfo^ minfo in t->GetMethods())
{
if (minfo->Name == "PrintCall")
{
Console::WriteLine("Overload of PrintCall: {0}" +
" IsHideBySig = {1}, DeclaringType = {2}",
minfo, minfo->IsHideBySig, minfo->DeclaringType);
}
}
// The method PrintCall in the derived class hides one overload of the
// method in Parent. Contrast this with Visual Basic, which hides by
// name instead of by name and signature. In Visual Basic, the
// parameterless overload of PrintCall would be unavailable from Child.
//
Console::WriteLine(
"------ Call the overloads of PrintCall available in Child ------");
childInstance->PrintCall();
childInstance->PrintCall(42);
// If Child is cast to the base type Parent, both overloads of the
// shadowed method can be called.
//
Console::WriteLine(
"------ Call the shadowed overloads of PrintCall ------");
Parent^ parentInstance = childInstance;
parentInstance->PrintCall();
parentInstance->PrintCall(42);
}
/* This code example produces the following output:
------ List the overloads of PrintCall in the derived class Child ------
Overload of PrintCall: Void PrintCall(Int32) IsHideBySig = True, DeclaringType = Child
Overload of PrintCall: Void PrintCall() IsHideBySig = True, DeclaringType = Parent
Overload of PrintCall: Void PrintCall(Int32) IsHideBySig = True, DeclaringType = Parent
------ Call the overloads of PrintCall available in Child ------
Parent's PrintCall()
Child's PrintCall(42)
------ Call the shadowed overloads of PrintCall ------
Parent's PrintCall()
Parent's PrintCall(42)
*/
import System.*;
import System.Reflection.*;
// The base class B contains an overloaded method M.
//
public class B
{
public void M()
{
Console.WriteLine("B's M()");
} //M
public void M(int x)
{
Console.WriteLine("B's M({0})", (Int32)x);
} //M
} //B
// The derived class D hides one overload of the inherited
// method M.
//
public class D extends B
{
public void M(int i)
{
Console.WriteLine("D's M({0})", (Int32)i);
} //M
} //D
public class Test
{
public static void main(String[] args)
{
D dInst = new D();
// In VJ#, the method in the derived class hides by name and by
// signature, so the overload in the derived class hides only one
// of the overloads in the base class.
//
Console.WriteLine("------ List the overloads of M in the "
+ "derived class D ------");
Type t = dInst.GetType();
for (int iCtr = 0; iCtr < t.GetMethods().get_Length(); iCtr++) {
MethodInfo mInfo = (MethodInfo)t.GetMethods().get_Item(iCtr);
if (mInfo.get_Name().Equals("M")) {
Console.WriteLine("Overload of M: {0} IsHideBySig = {1}, "
+ "DeclaringType = {2}", mInfo,
(System.Boolean)mInfo.get_IsHideBySig(),
mInfo.get_DeclaringType().ToString());
}
}
// The method M in the derived class hides one overload of the
// method in B. Contrast this with Visual Basic, which hides by
// name instead of by name and signature. In Visual Basic, the
// parameterless overload of M would be unavailable from D.
//
Console.WriteLine("------ Call the overloads of M available in D ------");
dInst.M();
dInst.M(42);
// If D is cast to the base type B, both overloads of the
// shadowed method can be called.
//
Console.WriteLine("------ Call the shadowed overloads of M ------");
B bInst = dInst;
bInst.M();
bInst.M(42);
} //main
} //Test
/* This code example produces the following output:
------ List the overloads of M in the derived class D ------
Overload of M: Void M(Int32) IsHideBySig = True, DeclaringType = D
Overload of M: Void M() IsHideBySig = True, DeclaringType = B
------ Call the overloads of M available in D ------
B's M()
D's M(42)
------ Call the shadowed overloads of M ------
B's M()
D's M(42)
*/
平台
Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、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
.NET Compact Framework
受以下版本支持：2.0、1.0