Control.HasChildren 屬性

public:
 property bool HasChildren { bool get(); };

[System.ComponentModel.Browsable(false)]
public bool HasChildren { get; }

[<System.ComponentModel.Browsable(false)>]
member this.HasChildren : bool

Public ReadOnly Property HasChildren As Boolean

屬性值

true如果控制項包含一個或多個子控制項;否則，。 false

屬性

BrowsableAttribute

範例

以下程式碼範例將控制項的 and BackColor 設定ForeColor為預設系統顏色。 如果控制項有任何子控制，程式碼會遞迴呼叫自己。 這個程式碼範例要求你有一個Form至少有一個子控制項;然而，若用子容器控制，例如PanelGroupBox一個或，並擁有自己的子控制，會更有效地展示遞迴。

   // Reset all the controls to the user's default Control color.
private:
   void ResetAllControlsBackColor( Control^ control )
   {
      control->BackColor = SystemColors::Control;
      control->ForeColor = SystemColors::ControlText;
      if ( control->HasChildren )
      {
         // Recursively call this method for each child control.
         IEnumerator^ myEnum = control->Controls->GetEnumerator();
         while ( myEnum->MoveNext() )
         {
            Control^ childControl = safe_cast<Control^>(myEnum->Current);
            ResetAllControlsBackColor( childControl );
         }
      }
   }

// Reset all the controls to the user's default Control color. 
private void ResetAllControlsBackColor(Control control)
{
   control.BackColor = SystemColors.Control;
   control.ForeColor = SystemColors.ControlText;
   if(control.HasChildren)
   {
      // Recursively call this method for each child control.
      foreach(Control childControl in control.Controls)
      {
         ResetAllControlsBackColor(childControl);
      }
   }
}

' Reset all the controls to the user's default Control color. 
Private Sub ResetAllControlsBackColor(control As Control)
   control.BackColor = SystemColors.Control
   control.ForeColor = SystemColors.ControlText
   If control.HasChildren Then
      ' Recursively call this method for each child control.
      Dim childControl As Control
      For Each childControl In  control.Controls
         ResetAllControlsBackColor(childControl)
      Next childControl
   End If
End Sub

備註

若集合 Controls 大 Count 於零， HasChildren 則該性質將返回 true。 若控制節點沒有子節點，存取 HasChildren 該屬性不會強制建立 a Control.ControlCollection ，因此在執行控制樹時，參考此屬性可帶來效能上的提升。

另請參閱

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