SortedList.IsSynchronized 属性
定义
重要
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获取一个值,该值指示对 SortedList 对象的访问是否同步(线程安全)。
public:
virtual property bool IsSynchronized { bool get(); };
public virtual bool IsSynchronized { get; }
member this.IsSynchronized : bool
Public Overridable ReadOnly Property IsSynchronized As Boolean
属性值
如果对 SortedList 对象的访问是同步的(线程安全),则为 true
;否则为 false
。 默认值为 false
。
实现
示例
下面的代码示例演示如何在整个枚举期间使用 SyncRoot 属性锁定集合。
SortedList^ myCollection = gcnew SortedList();
bool lockTaken = false;
try
{
Monitor::Enter(myCollection->SyncRoot, lockTaken);
for each (Object^ item in myCollection);
{
// Insert your code here.
}
}
finally
{
if (lockTaken)
{
Monitor::Exit(myCollection->SyncRoot);
}
}
SortedList myCollection = new SortedList();
lock (myCollection.SyncRoot)
{
foreach (object item in myCollection)
{
// Insert your code here.
}
}
Dim myCollection As New SortedList()
SyncLock myCollection.SyncRoot
For Each item In myCollection
' Insert your code here.
Next item
End SyncLock
检索此属性的值是一项 O(1)
操作。
下面的代码示例演示如何同步 SortedList 对象、确定 是否 SortedList 同步,以及如何使用同步的 SortedList。
#using <system.dll>
using namespace System;
using namespace System::Collections;
int main()
{
// Creates and initializes a new SortedList.
SortedList^ mySL = gcnew SortedList;
mySL->Add( 2, "two" );
mySL->Add( 3, "three" );
mySL->Add( 1, "one" );
mySL->Add( (int^)0, "zero" );
mySL->Add( 4, "four" );
// Creates a synchronized wrapper around the SortedList.
SortedList^ mySyncdSL = SortedList::Synchronized( mySL );
// Displays the sychronization status of both SortedLists.
Console::WriteLine( "mySL is {0}.", mySL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
Console::WriteLine( "mySyncdSL is {0}.", mySyncdSL->IsSynchronized ? (String^)"synchronized" : "not synchronized" );
}
/*
This code produces the following output.
mySL is not synchronized.
mySyncdSL is synchronized.
*/
using System;
using System.Collections;
public class SamplesSortedList
{
public static void Main()
{
// Creates and initializes a new SortedList.
SortedList mySL = new SortedList();
mySL.Add(2, "two");
mySL.Add(3, "three");
mySL.Add(1, "one");
mySL.Add(0, "zero");
mySL.Add(4, "four");
// Creates a synchronized wrapper around the SortedList.
SortedList mySyncdSL = SortedList.Synchronized(mySL);
// Displays the sychronization status of both SortedLists.
Console.WriteLine("mySL is {0}.", mySL.IsSynchronized ? "synchronized" : "not synchronized");
Console.WriteLine("mySyncdSL is {0}.", mySyncdSL.IsSynchronized ? "synchronized" : "not synchronized");
}
}
/*
This code produces the following output.
mySL is not synchronized.
mySyncdSL is synchronized.
*/
Imports System.Collections
Public Class SamplesSortedList
Public Shared Sub Main()
' Creates and initializes a new SortedList.
Dim mySL As New SortedList()
mySL.Add(2, "two")
mySL.Add(3, "three")
mySL.Add(1, "one")
mySL.Add(0, "zero")
mySL.Add(4, "four")
' Creates a synchronized wrapper around the SortedList.
Dim mySyncdSL As SortedList = SortedList.Synchronized(mySL)
' Displays the sychronization status of both SortedLists.
Dim msg As String
If mySL.IsSynchronized Then
msg = "synchronized"
Else
msg = "not synchronized"
End If
Console.WriteLine("mySL is {0}.", msg)
If mySyncdSL.IsSynchronized Then
msg = "synchronized"
Else
msg = "not synchronized"
End If
Console.WriteLine("mySyncdSL is {0}.", msg)
End Sub
End Class
' This code produces the following output.
'
' mySL is not synchronized.
' mySyncdSL is synchronized.
注解
若要保证 对象的线程安全 SortedList ,所有操作都必须通过 方法返回的 Synchronized 包装器完成。
枚举整个集合本质上不是一个线程安全的过程。 即使某个集合已同步,其他线程仍可以修改该集合,这会导致枚举数引发异常。 若要确保枚举过程中的线程安全性,可以在整个枚举期间锁定集合,或者捕获由其他线程进行的更改所导致的异常。