ContainerControl.ActiveControl Свойство

Определение

Получает или задает активный элемент управления в элементе управления контейнера.Gets or sets the active control on the container control.

public:
 property System::Windows::Forms::Control ^ ActiveControl { System::Windows::Forms::Control ^ get(); void set(System::Windows::Forms::Control ^ value); };
[System.ComponentModel.Browsable(false)]
public System.Windows.Forms.Control ActiveControl { get; set; }
member this.ActiveControl : System.Windows.Forms.Control with get, set
Public Property ActiveControl As Control

Значение свойства

Элемент управления Control, являющийся активным в настоящий момент в ContainerControl.The Control that is currently active on the ContainerControl.

Реализации

Атрибуты

Исключения

Невозможно активизировать присвоенный элемент управления Control.The Control assigned could not be activated.

Примеры

Следующий пример кода наследуется от ScrollableControl класса и IContainerControl реализует интерфейс.The following code example inherits from the ScrollableControl class and implements the IContainerControl interface. Реализация добавляется в ActiveControl свойство ActivateControl и метод.Implementation is added to the ActiveControl property and the ActivateControl method.

using namespace System;
using namespace System::Windows::Forms;
using namespace System::Drawing;

public ref class MyContainer: public ScrollableControl, public IContainerControl
{
private:
   Control^ activeControl;

public:
   MyContainer()
   {
      // Make the container control Blue so it can be distinguished on the form.
      this->BackColor = Color::Blue;

      // Make the container scrollable.
      this->AutoScroll = true;
   }

   property Control^ ActiveControl 
   {
      // Add implementation to the IContainerControl.ActiveControl property.
      virtual Control^ get()
      {
         return activeControl;
      }

      virtual void set( Control^ value )
      {
         
         // Make sure the control is a member of the ControlCollection.
         if ( this->Controls->Contains( value ) )
         {
            activeControl = value;
         }
      }
   }

   // Add implementations to the IContainerControl.ActivateControl(Control) method.
   virtual bool ActivateControl( Control^ active )
   {
      if ( this->Controls->Contains( active ) )
      {
         // Select the control and scroll the control into view if needed.
         active->Select(  );
         this->ScrollControlIntoView( active );
         this->activeControl = active;
         return true;
      }

      return false;
   }
};
using System;
using System.Windows.Forms;
using System.Drawing;

    public class MyContainer : ScrollableControl, IContainerControl
    {
        private Control activeControl;
        public MyContainer() 
        {
            // Make the container control Blue so it can be distinguished on the form.
            this.BackColor = Color.Blue;
            
            // Make the container scrollable.
            this.AutoScroll = true;
        }

        // Add implementation to the IContainerControl.ActiveControl property.
        public Control ActiveControl
        {
            get
            {
                return activeControl;
            }

            set
            {
                // Make sure the control is a member of the ControlCollection.
                if(this.Controls.Contains(value))
                {
                    activeControl = value;
                }
            }
        }

        // Add implementations to the IContainerControl.ActivateControl(Control) method.
        public bool ActivateControl(Control active)
        {
            if(this.Controls.Contains(active))
            {
                // Select the control and scroll the control into view if needed.
                active.Select();
                this.ScrollControlIntoView(active);
                this.activeControl = active;
                return true;
            }
            return false;
        }
    }
Imports System.Windows.Forms
Imports System.Drawing

   Public Class MyContainerControl
      Inherits ScrollableControl
      Implements IContainerControl 

      Private myActiveControl As Control
      
      Public Sub New()
         ' Make the container control Blue so it can be distinguished on the form.
         Me.BackColor = Color.Blue
         
         ' Make the container scrollable.
         Me.AutoScroll = True
      End Sub 
      
      ' Add implementation to the IContainerControl.ActiveControl property.
      Public Property ActiveControl() As Control Implements IContainerControl.ActiveControl
         Get
            Return Me.myActiveControl
         End Get
         
         Set
            ' Make sure the control is a member of the ControlCollection.
            If Me.Controls.Contains(value) Then
               Me.myActiveControl = value
            End If
         End Set
      End Property
      
      ' Add implementation to the IContainerControl.ActivateControl(Control) method.
      public Function ActivateControl(active As Control) As Boolean Implements IContainerControl.ActivateControl
         If Me.Controls.Contains(active) Then
            ' Select the control and scroll the control into view if needed.
            active.Select()
            Me.ScrollControlIntoView(active)
            Me.myActiveControl = active
            Return True
         End If
         Return False
      End Function 

   End Class  

Комментарии

ActiveControl Свойство активирует или получает активный элемент управления контейнера.The ActiveControl property activates or retrieves the active control on the container control.

Чтобы получить допустимое значение из этого свойства, объект, вызывающий его, должен содержать или быть включен в вызывающий элемент управления.In order to receive a valid value from this property, the object that calls it must either contain or be contained in the control it is calling. Если одна из форм пытается вызвать ActiveControl свойства другой формы, она получит неопределенное значение.If one form tries to call another form's ActiveControl properties, it will receive an undefined value. В этом случае необходимо определить собственный механизм связи между формами для передачи этих данных.In this case, you need to define your own communication mechanism between the forms to pass this data.

Применяется к

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