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ControlCollection.SyncRoot 屬性

定義

取得可用來對控制項集合進行同步 (Synchronize) 存取的物件。

public:
 property System::Object ^ SyncRoot { System::Object ^ get(); };
public object SyncRoot { get; }
member this.SyncRoot : obj
Public ReadOnly Property SyncRoot As Object

屬性值

用來同步處理集合的 Object

實作

範例

下列程式碼範例會建立方法,以列舉 ControlCollection 控制項 myButtonButton 集合。 建立列舉值時, IsSynchronized 會檢查 屬性,以查看作業是否為安全線程,如果不是,則會 SyncRoot 使用 屬性來取得物件,讓作業執行緒安全。 當列舉完成時,屬性的值 IsReadOnly 會寫入為 Text 包含頁面上控制項的 Label 屬性。

// Create a method that enuberates through a 
// button//s ControlCollection in a thread-safe manner.  
public void ListControlCollection(object sender, EventArgs e)
{
   IEnumerator myEnumerator = myButton.Controls.GetEnumerator();

   // Check the IsSynchronized property. If False,
   // use the SyncRoot method to get an object that 
   // allows the enumeration of all controls to be 
   // thread safe.
   if (myButton.Controls.IsSynchronized == false)
   {
       lock (myButton.Controls.SyncRoot)
       {
           while (myEnumerator.MoveNext())
           {

               Object myObject = myEnumerator.Current;

               LiteralControl childControl = (LiteralControl)myEnumerator.Current;
               Response.Write("<b><br /> This is the  text of the child Control  </b>: " +
                              childControl.Text);
           }
           msgReadOnly.Text = myButton.Controls.IsReadOnly.ToString();
       }
   }       
}
' Create a method that enuberates through a 
' button's ControlCollection in a thread-safe manner.  
Public Sub ListControlCollection(sender As Object, e As EventArgs)
   Dim myEnumerator As IEnumerator = myButton.Controls.GetEnumerator()

   ' Check the IsSynchronized property. If False,
   ' use the SyncRoot method to get an object that 
   ' allows the enumeration of all controls to be 
   ' thread safe.
   If myButton.Controls.IsSynchronized = False Then
     SyncLock myButton.Controls.SyncRoot
       While (myEnumerator.MoveNext())

       Dim myObject As Object  = myEnumerator.Current
           
         Dim childControl As LiteralControl = CType(myEnumerator.Current, LiteralControl)
         Response.Write("<b><br /> This is the  text of the child Control  </b>: " & _
                        childControl.Text)
       End While
      msgReadOnly.Text = myButton.Controls.IsReadOnly.ToString()
      
      End SyncLock
   End If       
 End Sub

適用於

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