Form.ActiveForm Property

Definition

Namespace:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Source:

Form.cs

Gets the currently active form for this application.

public:
 static property System::Windows::Forms::Form ^ ActiveForm { System::Windows::Forms::Form ^ get(); };

public static System.Windows.Forms.Form? ActiveForm { get; }

static member ActiveForm : System.Windows.Forms.Form

Public Shared ReadOnly Property ActiveForm As Form

Property Value

Form

A Form that represents the currently active form, or null if there is no active form.

Examples

The following example gets the active form and disables all the controls on the form. The example uses the Controls collection of the form to iterate through each control on the form and disable the controls.

void DisableActiveFormControls()
{
   
   // Create an instance of a form and assign it the currently active form.
   Form^ currentForm = Form::ActiveForm;
   
   // Loop through all the controls on the active form.
   for ( int i = 0; i < currentForm->Controls->Count; i++ )
   {
      
      // Disable each control in the active form's control collection.
      currentForm->Controls[ i ]->Enabled = false;

   }
}

public void DisableActiveFormControls()
 {
    // Create an instance of a form and assign it the currently active form.
    Form currentForm = Form.ActiveForm;
    
    // Loop through all the controls on the active form.
    for (int i = 0; i < currentForm.Controls.Count; i++)
    {
       // Disable each control in the active form's control collection.
       currentForm.Controls[i].Enabled = false;
    }
 }

Public Sub DisableActiveFormControls()
    ' Create an instance of a form and assign it the currently active form.
    Dim currentForm As Form = Form.ActiveForm
    
    ' Loop through all the controls on the active form.
    Dim i As Integer
    For i = 0 To currentForm.Controls.Count - 1
        ' Disable each control in the active form's control collection.
        currentForm.Controls(i).Enabled = False
    Next i
End Sub

Remarks

You can use this method to obtain a reference to the currently active form to perform actions on the form or its controls.

If your application is a multiple-document interface (MDI) application, use the ActiveMdiChild property to obtain the currently active MDI child form.

See also

• ActiveMdiChild