Form.ActiveMdiChild プロパティ

定義

現在アクティブなマルチ ドキュメント インターフェイス (MDI) 子ウィンドウを取得します。Gets the currently active multiple-document interface (MDI) child window.

public:
 property System::Windows::Forms::Form ^ ActiveMdiChild { System::Windows::Forms::Form ^ get(); };
[System.ComponentModel.Browsable(false)]
public System.Windows.Forms.Form ActiveMdiChild { get; }
member this.ActiveMdiChild : System.Windows.Forms.Form
Public ReadOnly Property ActiveMdiChild As Form

プロパティ値

現在アクティブな MDI 子ウィンドウを表す Form を返します。現在子ウィンドウが存在しない場合は null を返します。Returns a Form that represents the currently active MDI child window, or null if there are currently no child windows present.

属性

次の例では、アクティブな MDI 子フォームへの参照を取得し、フォーム上のすべての TextBox コントロールをループして、Text プロパティをリセットします。The following example obtains a reference to the active MDI child form and loops through all TextBox controls on the form, resetting their Text properties. この例では、MDI 親フォームが作成されており、このメソッド呼び出しが MDI 親フォームから実行されている必要があります。This example requires that an MDI parent form has been created and that this method call is being made from the MDI parent form.

public:
   void ClearAllChildFormText()
   {
      
      // Obtain a reference to the currently active MDI child form.
      Form^ tempChild = this->ActiveMdiChild;
      
      // Loop through all controls on the child form.
      for ( int i = 0; i < tempChild->Controls->Count; i++ )
      {
         
         // Determine if the current control on the child form is a TextBox.
         if ( dynamic_cast<TextBox^>(tempChild->Controls[ i ]) )
         {
            
            // Clear the contents of the control since it is a TextBox.
            tempChild->Controls[ i ]->Text = "";
         }

      }
   }

public void ClearAllChildFormText()
 {
    // Obtain a reference to the currently active MDI child form.
    Form tempChild = this.ActiveMdiChild;
    
    // Loop through all controls on the child form.
    for (int i = 0; i < tempChild.Controls.Count; i++)
    {
       // Determine if the current control on the child form is a TextBox.
       if (tempChild.Controls[i] is TextBox)
       {
          // Clear the contents of the control since it is a TextBox.
          tempChild.Controls[i].Text = "";
       }
    }
 }
    
Public Sub ClearAllChildFormText()
    ' Obtain a reference to the currently active MDI child form.
    Dim tempChild As Form = Me.ActiveMdiChild
    
    ' Loop through all controls on the child form.
    Dim i As Integer
    For i = 0 To tempChild.Controls.Count - 1
        ' Determine if the current control on the child form is a TextBox.
        If TypeOf tempChild.Controls(i) Is TextBox Then
            ' Clear the contents of the control since it is a TextBox.
            tempChild.Controls(i).Text = ""
        End If
    Next i
End Sub

注釈

このメソッドを使用すると、mdi 子フォームが MDI アプリケーションで開かれているかどうかを確認できます。You can use this method to determine whether there are any MDI child forms open in your MDI application. また、このメソッドを使用して、mdi 親フォームから、またはアプリケーションに表示される別のフォームから、MDI 子ウィンドウに対して操作を実行することもできます。You can also use this method to perform operations on an MDI child window from its MDI parent form or from another form that is displayed in your application.

現在アクティブなフォームが MDI 子フォームでない場合は、ActiveForm プロパティを使用して参照を取得できます。If the currently active form is not an MDI child form, you can use the ActiveForm property to obtain a reference to it.

適用対象

こちらもご覧ください