ContainerControl.ActiveControl Properti

Definisi

Ruang nama:

System.Windows.Forms

Rakitan:

System.Windows.Forms.dll

Sumber:

ContainerControl.cs

Mendapatkan atau mengatur kontrol aktif pada kontrol kontainer.

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; }

[<System.ComponentModel.Browsable(false)>]
member this.ActiveControl : System.Windows.Forms.Control with get, set

Public Property ActiveControl As Control

Nilai Properti

Control

Control yang saat ini aktif pada ContainerControl.

Penerapan

ActiveControl

Atribut

BrowsableAttribute

Pengecualian

ArgumentException

Yang Control ditetapkan tidak dapat diaktifkan.

Contoh

Contoh kode berikut mewarisi dari ScrollableControl kelas dan mengimplementasikan IContainerControl antarmuka. Implementasi ditambahkan ke ActiveControl properti dan ActivateControl metode .

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

Keterangan

Properti ActiveControl mengaktifkan atau mengambil kontrol aktif pada kontrol kontainer.

Untuk menerima nilai yang valid dari properti ini, objek yang memanggilnya harus berisi atau terkandung dalam kontrol yang dipanggilnya. Jika satu formulir mencoba memanggil properti formulir ActiveControl lain, formulir tersebut akan menerima nilai yang tidak ditentukan. Dalam hal ini, Anda perlu menentukan mekanisme komunikasi Anda sendiri antara formulir untuk meneruskan data ini.

Lihat juga

• ScrollableControl
• Control