ContainerControl.ActiveControl ContainerControl.ActiveControl ContainerControl.ActiveControl ContainerControl.ActiveControl Property

Definizione

Ottiene o imposta il controllo attivo sul controllo contenitore.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

Valore della proprietà

Il Control che è attualmente attivo nel ContainerControl.The Control that is currently active on the ContainerControl.

Implementazioni

Eccezioni

Il Control assegnato non è stato possibile attivare.The Control assigned could not be activated.

Esempi

Esempio di codice seguente eredita dal ScrollableControl classe e implementa la IContainerControl interfaccia.The following code example inherits from the ScrollableControl class and implements the IContainerControl interface. L'implementazione viene aggiunta per il ActiveControl proprietà e il ActivateControl (metodo).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
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  

Commenti

Il ActiveControl proprietà attiva o recupera il controllo attivo sul controllo contenitore.The ActiveControl property activates or retrieves the active control on the container control.

Per ricevere un valore valido da questa proprietà, l'oggetto che lo chiama deve contenere o essere contenuto nel controllo che chiama.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. Se un unico modulo tenta di chiamare un altro formato ActiveControl proprietà, riceverà un valore indefinito.If one form tries to call another form's ActiveControl properties, it will receive an undefined value. In questo caso, è necessario definire il proprio meccanismo di comunicazione tra i form per passare i dati.In this case, you need to define your own communication mechanism between the forms to pass this data.

Si applica a

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