Επεξεργασία

Κοινή χρήση μέσω

Control.Visible Property

  • Reference

Definition

Namespace:
System.Windows.Forms
Assembly:
System.Windows.Forms.dll
Source:
Control.cs
Source:
Control.cs
Source:
Control.cs

Gets or sets a value indicating whether the control and all its child controls are displayed.

public:
 property bool Visible { bool get(); void set(bool value); };
public bool Visible { get; set; }
member this.Visible : bool with get, set
Public Property Visible As Boolean

Property Value

Boolean

true to display the control and its child controls; otherwise, false. The default is true. When getting the value, true is returned only if the control is visible and the parent control, if it exists, is visible.

Examples

The following code example uses the derived classes VScrollBar and HScrollBar and sets their Visible property values, based on the size of an Image being displayed in a PictureBox control. This example requires that a PictureBox has been created on a form and that HScrollBar and VScrollBar controls have been created on the PictureBox. This code should be called when the image is loaded into the picture box and by the Resize event of the form.

public:
   void DisplayScrollBars()
   {
      // Display or hide the scroll bars based upon  
      // whether the image is larger than the PictureBox.
      if ( pictureBox1->Width > pictureBox1->Image->Width )
      {
         hScrollBar1->Visible = false;
      }
      else
      {
         hScrollBar1->Visible = true;
      }

      if ( pictureBox1->Height > pictureBox1->Image->Height )
      {
         vScrollBar1->Visible = false;
      }
      else
      {
         vScrollBar1->Visible = true;
      }
   }

public void DisplayScrollBars()
 {
    // Display or hide the scroll bars based upon  
    // whether the image is larger than the PictureBox.
    if (pictureBox1.Width > pictureBox1.Image.Width)
    {
       hScrollBar1.Visible = false;
    }
    else
    {
       hScrollBar1.Visible = true;
    }
    
    if (pictureBox1.Height > pictureBox1.Image.Height)
    {
       vScrollBar1.Visible = false;
    }
    else
    {
       vScrollBar1.Visible = true;
    }
 }

Public Sub DisplayScrollBars()
    ' Display or hide the scroll bars based upon  
    ' whether the image is larger than the PictureBox.
    If pictureBox1.Width > pictureBox1.Image.Width Then
        hScrollBar1.Visible = False
    Else
        hScrollBar1.Visible = True
    End If
    
    If pictureBox1.Height > pictureBox1.Image.Height Then
        vScrollBar1.Visible = False
    Else
        vScrollBar1.Visible = True
    End If
End Sub

Remarks

If you set Visible to true:

  • The control might not be visible to the user if it's obscured behind other controls.
  • The control won't be displayed if the parent control is not visible.

Applies to

See also