GC.GetGeneration 方法

参考

定义

命名空间:: System

程序集:: mscorlib.dll, System.Runtime.dll

程序集:: netstandard.dll, System.Runtime.dll

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。

返回对象的当前代数。

重载

GetGeneration(Object)	返回指定对象的当前代数。
GetGeneration(WeakReference)	返回指定弱引用的目标的当前代数。

GetGeneration(Object)

Source:: GC.CoreCLR.cs

Source:: GC.cs

Source:: GC.cs

Source:: GC.cs

返回指定对象的当前代数。

public:
 static int GetGeneration(System::Object ^ obj);

public static int GetGeneration(object obj);

static member GetGeneration : obj -> int

Public Shared Function GetGeneration (obj As Object) As Integer

参数

obj: Object

检索其代信息的对象。

Int32

或 Int32.MaxValue 的obj当前代号。

示例

以下示例演示如何使用 GetGeneration 方法确定对象的期限。然后，该示例执行垃圾回收以清理内存，并在控制台中比较收集前和回收后的内存总计。

using namespace System;
const long maxGarbage = 1000;
ref class MyGCCollectClass
{
public:
   void MakeSomeGarbage()
   {
      Version^ vt;
      for ( int i = 0; i < maxGarbage; i++ )
      {
         
         // Create objects and release them to fill up memory
         // with unused objects.
         vt = gcnew Version;

      }
   }

};

int main()
{
   MyGCCollectClass^ myGCCol = gcnew MyGCCollectClass;
   
   // Determine the maximum number of generations the system
   // garbage collector currently supports.
   Console::WriteLine( "The highest generation is {0}", GC::MaxGeneration );
   myGCCol->MakeSomeGarbage();
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   
   // Determine the best available approximation of the number
   // of bytes currently allocated in managed memory.
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
   
   // Perform a collection of generation 0 only.
   GC::Collect( 0 );
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
   
   // Perform a collection of all generations up to and including 2.
   GC::Collect( 2 );
   
   // Determine which generation myGCCol object is stored in.
   Console::WriteLine( "Generation: {0}", GC::GetGeneration( myGCCol ) );
   Console::WriteLine( "Total Memory: {0}", GC::GetTotalMemory( false ) );
}

using System;

namespace GCCollectIntExample
{
    class MyGCCollectClass
    {
        private const long maxGarbage = 1000;

        static void Main()
        {
            MyGCCollectClass myGCCol = new MyGCCollectClass();

            // Determine the maximum number of generations the system
        // garbage collector currently supports.
            Console.WriteLine("The highest generation is {0}", GC.MaxGeneration);

            myGCCol.MakeSomeGarbage();

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));

            // Determine the best available approximation of the number
        // of bytes currently allocated in managed memory.
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));

            // Perform a collection of generation 0 only.
            GC.Collect(0);

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));

            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));

            // Perform a collection of all generations up to and including 2.
            GC.Collect(2);

            // Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol));
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(false));
            Console.Read();
        }

        void MakeSomeGarbage()
        {
            Version vt;

            for(int i = 0; i < maxGarbage; i++)
            {
                // Create objects and release them to fill up memory
        // with unused objects.
                vt = new Version();
            }
        }
    }
}

open System

let maxGarbage = 1000

type MyGCCollectClass() =
    member _.MakeSomeGarbage() =
        for _ = 1 to maxGarbage do
            // Create objects and release them to fill up memory with unused objects.
            Version() |> ignore

[<EntryPoint>]
let main _ =
    let myGCCol = MyGCCollectClass()

    // Determine the maximum number of generations the system
    // garbage collector currently supports.
    printfn $"The highest generation is {GC.MaxGeneration}"

    myGCCol.MakeSomeGarbage()

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"

    // Determine the best available approximation of the number
    // of bytes currently allocated in managed memory.
    printfn $"Total Memory: {GC.GetTotalMemory false}"

    // Perform a collection of generation 0 only.
    GC.Collect 0

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"

    printfn $"Total Memory: {GC.GetTotalMemory false}"

    // Perform a collection of all generations up to and including 2.
    GC.Collect 2

    // Determine which generation myGCCol object is stored in.
    printfn $"Generation: {GC.GetGeneration myGCCol}"
    printfn $"Total Memory: {GC.GetTotalMemory false}"

    0

Namespace GCCollectInt_Example
    Class MyGCCollectClass
        Private maxGarbage As Long = 10000

        Public Shared Sub Main()
            Dim myGCCol As New MyGCCollectClass

            'Determine the maximum number of generations the system
            'garbage collector currently supports.
            Console.WriteLine("The highest generation is {0}", GC.MaxGeneration)

            myGCCol.MakeSomeGarbage()

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))

            'Determine the best available approximation of the number 
            'of bytes currently allocated in managed memory.
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))

            'Perform a collection of generation 0 only.
            GC.Collect(0)

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))

            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))

            'Perform a collection of all generations up to and including 2.
            GC.Collect(2)

            'Determine which generation myGCCol object is stored in.
            Console.WriteLine("Generation: {0}", GC.GetGeneration(myGCCol))
            Console.WriteLine("Total Memory: {0}", GC.GetTotalMemory(False))
            Console.Read()

        End Sub


        Sub MakeSomeGarbage()
            Dim vt As Version

            Dim i As Integer
            For i = 0 To maxGarbage - 1
                'Create objects and release them to fill up memory
                'with unused objects.
                vt = New Version
            Next i
        End Sub
    End Class
End Namespace

注解

使用此方法确定对象的期限，然后将该信息与方法一起使用 Collect ，以强制垃圾回收器在同一代中收集对象。例如，当你有一组作为组创建且同时变得不可访问的对象时，请使用此方法。

从 .NET 8 开始，此方法可能会返回 MaxValue 在非 GC 堆上分配的对象。有关详细信息，请参阅 GC。GetGeneration 可能会返回 Int32.MaxValue。

另请参阅

MaxGeneration

适用于

GetGeneration(WeakReference)

Source:: GC.CoreCLR.cs

Source:: GC.CoreCLR.cs

Source:: GC.CoreCLR.cs

Source:: GC.CoreCLR.cs

返回指定弱引用的目标的当前代数。

public:
 static int GetGeneration(WeakReference ^ wo);

public static int GetGeneration(WeakReference wo);

static member GetGeneration : WeakReference -> int

Public Shared Function GetGeneration (wo As WeakReference) As Integer

参数

wo: WeakReference

引用要确定其代数的目标对象的 WeakReference。

Int32

或 MaxValue的目标的wo当前代号。

例外

ArgumentException

已经对 wo 执行了垃圾回收。

ArgumentNullException

弱引用的目标已被垃圾回收。

示例

以下示例演示如何使用 GetGeneration 方法来确定弱引用对象的期限。

using namespace System;
ref class MyGCCollectClass
{
private:
   static const long maxGarbage = 1000;

public:
   void MakeSomeGarbage()
   {
      Version^ vt;
      for ( int i = 0; i < maxGarbage; i++ )
      {
         
         // Create objects and release them to fill up memory
         // with unused objects.
         vt = gcnew Version;

      }
   }

};

int main()
{
   
   // Create a strong reference to an Object.
   MyGCCollectClass^ myGCCol = gcnew MyGCCollectClass;
   
   // Put some objects in memory.
   myGCCol->MakeSomeGarbage();
   
   // Get the generation of managed memory where myGCCol is stored.
   Console::WriteLine( "The object is in generation: {0}", GC::GetGeneration( myGCCol ) );
   
   // Perform a full garbage collection.
   // Because there is a strong reference to myGCCol, it will
   // not be garbage collected.
   GC::Collect();
   
   // Get the generation of managed memory where myGCCol is stored.
   Console::WriteLine( "The object is in generation: {0}", GC::GetGeneration( myGCCol ) );
   
   // Create a WeakReference to myGCCol.
   WeakReference^ wkref = gcnew WeakReference( myGCCol );
   
   // Remove the strong reference to myGCCol.
   myGCCol = nullptr;
   
   // Get the generation of managed memory where wkref is stored.
   Console::WriteLine( "The WeakReference to the object is in generation: {0}", GC::GetGeneration( wkref ) );
   
   // Perform another full garbage collection.
   // A WeakReference will not survive a garbage collection.
   GC::Collect();
   
   // Try to get the generation of managed memory where wkref is stored.
   // Because it has been collected, an exception will be thrown.
   try
   {
      Console::WriteLine( "The WeakReference to the object is in generation: {0}", GC::GetGeneration( wkref ) );
      Console::Read();
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "The WeakReference to the object has been garbage collected: ' {0}'", e );
   }

}

using System;

namespace GCGetGenerationWeakExample
{
    public class MyGCCollectClass
    {
        private const long maxGarbage = 1000;

        static void Main()
        {
            // Create a strong reference to an object.
            MyGCCollectClass myGCCol = new MyGCCollectClass();

            // Put some objects in memory.
            myGCCol.MakeSomeGarbage();

            // Get the generation of managed memory where myGCCol is stored.
            Console.WriteLine("The object is in generation: {0}", GC.GetGeneration(myGCCol));
                        
            // Perform a full garbage collection.
            // Because there is a strong reference to myGCCol, it will
            // not be garbage collected.
            GC.Collect();
            
            // Get the generation of managed memory where myGCCol is stored.
            Console.WriteLine("The object is in generation: {0}", GC.GetGeneration(myGCCol));
            
            // Create a WeakReference to myGCCol.
            WeakReference wkref = new WeakReference(myGCCol);
            // Remove the strong reference to myGCCol.
            myGCCol = null;

            // Get the generation of managed memory where wkref is stored.
            Console.WriteLine("The WeakReference to the object is in generation: {0}", GC.GetGeneration(wkref));
            
            // Perform another full garbage collection.
            // A WeakReference will not survive a garbage collection.
            GC.Collect();
        
            // Try to get the generation of managed memory where wkref is stored.
            // Because it has been collected, an exception will be thrown.
            try
            {
                Console.WriteLine("The WeakReference to the object is in generation: {0}", GC.GetGeneration(wkref));
                Console.Read();
            }
            catch(Exception e)
            {
                Console.WriteLine("The WeakReference to the object has been garbage collected: '{0}'", e);
                Console.Read();
            }
        }

        void MakeSomeGarbage()
        {
            Version vt;

            for(int i = 0; i < maxGarbage; i++)
            {
                // Create objects and release them to fill up memory
                // with unused objects.
                vt = new Version();
            }
        }
    }
}

open System

let maxGarbage = 1000

[<AllowNullLiteral>]
type MyGCCollectClass() =
    member _.MakeSomeGarbage() =
        for i = 1 to maxGarbage do
            // Create objects and release them to fill up memory
            // with unused objects.
            Version() |> ignore

// Create a strong reference to an object.
let mutable myGCCol = MyGCCollectClass()

// Put some objects in memory.
myGCCol.MakeSomeGarbage()

// Get the generation of managed memory where myGCCol is stored.
printfn $"The object is in generation: {GC.GetGeneration myGCCol}"
            
// Perform a full garbage collection.
// Because there is a strong reference to myGCCol, it will
// not be garbage collected.
GC.Collect()

// Get the generation of managed memory where myGCCol is stored.
printfn $"The object is in generation: {GC.GetGeneration myGCCol}"

// Create a WeakReference to myGCCol.
let wkref = WeakReference myGCCol
// Remove the strong reference to myGCCol.
myGCCol <- null

// Get the generation of managed memory where wkref is stored.
printfn $"The WeakReference to the object is in generation: {GC.GetGeneration wkref}"

// Perform another full garbage collection.
// A WeakReference will not survive a garbage collection.
GC.Collect()

// Try to get the generation of managed memory where wkref is stored.
// Because it has been collected, an exception will be thrown.
try
    printfn $"The WeakReference to the object is in generation: {GC.GetGeneration wkref}"
    stdin.Read() |> ignore
with e ->
    printfn $"The WeakReference to the object has been garbage collected: '{e}'"
    stdin.Read() |> ignore

Namespace GCGetGenerationWeakExample

   Class MyGCCollectClass
      Private maxGarbage As Long = 1000

      Public Shared Sub Main()
         ' Create a strong reference to an object.
         Dim myGCCol As New MyGCCollectClass

         ' Put some objects in memory.
         myGCCol.MakeSomeGarbage()

         ' Get the generation of managed memory where myGCCol is stored.
         Console.WriteLine("The object is in generation: {0}", _
                            GC.GetGeneration(myGCCol))

         ' Perform a full garbage collection.
         ' Because there is a strong reference to myGCCol, it will
         ' not be garbage collected.
         GC.Collect()

         ' Get the generation of managed memory where myGCCol is stored.
         Console.WriteLine("The object is in generation: {0}", _
                            GC.GetGeneration(myGCCol))

         ' Create a WeakReference to myGCCol.
         Dim wkref As New WeakReference(myGCCol)
         ' Remove the strong reference to myGCCol.
         myGCCol = Nothing

         ' Get the generation of managed memory where wkref is stored.
         Console.WriteLine("The WeakReference to the object is in generation: {0}", _
                           GC.GetGeneration(wkref))

         ' Perform another full garbage collection.
         ' A WeakReference will not survive a garbage collection.
         GC.Collect()

         ' Try to get the generation of managed memory where wkref is stored.
         ' Because it has been collected, an exception will be thrown.
         Try
            Console.WriteLine("The WeakReference to the object is in generation: {0}", _
                               GC.GetGeneration(wkref))
            Console.Read()
         Catch e As Exception
            Console.WriteLine("The WeakReference to the object " & _
                              "has been garbage collected: '{0}'", e)
            Console.Read()
         End Try
      End Sub


      Sub MakeSomeGarbage()
         Dim vt As Version

         Dim i As Integer
         For i = 0 To maxGarbage - 1
            ' Create objects and release them to fill up memory
            ' with unused objects.
            vt = New Version
         Next i
      End Sub
   End Class
End Namespace

注解

从 .NET 8 开始，此方法可能会返回 MaxValue 在非 GC 堆上分配的对象。有关详细信息，请参阅 GC。GetGeneration 可能会返回 Int32.MaxValue。

另请参阅

MaxGeneration

适用于

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通过

GC.GetGeneration 方法

定义

重载

GetGeneration(Object)

参数

返回

示例

注解

另请参阅

适用于

GetGeneration(WeakReference)

参数

返回

例外

示例

注解

另请参阅

适用于

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