MeasureItemEventArgs Class


Provides data for the MeasureItem event of the ListBox, ComboBox, CheckedListBox, and MenuItem controls.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)


Public Class MeasureItemEventArgs
	Inherits EventArgs

System_CAPS_pubmethodMeasureItemEventArgs(Graphics, Int32)

Initializes a new instance of the MeasureItemEventArgs class.

System_CAPS_pubmethodMeasureItemEventArgs(Graphics, Int32, Int32)

Initializes a new instance of the MeasureItemEventArgs class providing a parameter for the item height.


Gets the Graphics object to measure against.


Gets the index of the item for which the height and width is needed.


Gets or sets the height of the item specified by the Index.


Gets or sets the width of the item specified by the Index.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

This event is sent when the OwnerDraw property of ListBox, ComboBox, CheckedListBox, or MenuItem is set to true. It is used to tell the drawing function how to size an item.

For information about the event model, see Handling and Raising Events.

The following code example demonstrates how to use the Graphics property to perform custom drawing of the items in a ListBox.

Public Class Form1
   Inherits System.Windows.Forms.Form
   Private WithEvents listBox1 As System.Windows.Forms.ListBox
   Private components As System.ComponentModel.Container = Nothing

   Private FontSize As Single = 12.0F

   '  This sample displays a ListBox that contains a list of all the fonts
   '  installed on the system and draws each item in its respective font.
   Public Sub New()

      ' Populate control with the fonts installed on the system.
      Dim families As FontFamily() = FontFamily.Families

      Dim family As FontFamily
      For Each family In families
         Dim style As FontStyle = FontStyle.Regular

         ' Monotype Corsiva is only available in italic
         If family.Name = "Monotype Corsiva" Then
            style = style Or FontStyle.Italic
         End If

         listBox1.Items.Add(New ListBoxFontItem(New Font(family.Name, FontSize, style, GraphicsUnit.Point)))
      Next family
   End Sub

   Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
      If disposing Then
         If (components IsNot Nothing) Then
         End If

         If (foreColorBrush IsNot Nothing) Then
         End If
      End If

   End Sub

   Private Sub InitializeComponent()
      Me.listBox1 = New System.Windows.Forms.ListBox()
      ' listBox1
      Me.listBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawVariable
      Me.listBox1.Location = New System.Drawing.Point(16, 48)
      Me.listBox1.Name = "listBox1"
      Me.listBox1.SelectionMode = System.Windows.Forms.SelectionMode.MultiExtended
      Me.listBox1.Size = New System.Drawing.Size(256, 134)
      Me.listBox1.TabIndex = 0
      ' Form1
      Me.ClientSize = New System.Drawing.Size(292, 273)
      Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.listBox1})
      Me.Name = "Form1"
      Me.Text = "Form1"
   End Sub

   <STAThread()> Shared Sub Main()
      Application.Run(New Form1())
   End Sub

   Private Sub listBox1_MeasureItem(ByVal sender As Object, ByVal e As System.Windows.Forms.MeasureItemEventArgs) Handles listBox1.MeasureItem
      Dim font As Font = CType(listBox1.Items(e.Index), ListBoxFontItem).Font
      Dim stringSize As SizeF = e.Graphics.MeasureString(font.Name, font)

      ' Set the height and width of the item
      e.ItemHeight = CInt(stringSize.Height)
      e.ItemWidth = CInt(stringSize.Width)
   End Sub

   ' For efficiency, cache the brush used for drawing.
   Private foreColorBrush As SolidBrush

   Private Sub listBox1_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles listBox1.DrawItem
      Dim brush As Brush

      ' Create the brush using the ForeColor specified by the DrawItemEventArgs
      If foreColorBrush Is Nothing Then
         foreColorBrush = New SolidBrush(e.ForeColor)
         If Not foreColorBrush.Color.Equals(e.ForeColor) Then
            ' The control's ForeColor has changed, so dispose of the cached brush and
            ' create a new one.
            foreColorBrush = New SolidBrush(e.ForeColor)
         End If
      End If

      ' Select the appropriate brush depending on if the item is selected.
      ' Since State can be a combinateion (bit-flag) of enum values, you can't use
      ' "==" to compare them.
      If (e.State And DrawItemState.Selected) = DrawItemState.Selected Then
         brush = SystemBrushes.HighlightText
         brush = foreColorBrush
      End If

      ' Perform the painting.
      Dim font As Font = CType(listBox1.Items(e.Index), ListBoxFontItem).Font
      e.Graphics.DrawString(font.Name, font, brush, e.Bounds.X, e.Bounds.Y)
   End Sub

   '  A wrapper class for use with storing Fonts in a ListBox.  Since ListBox uses the
   '  ToString() of its items for the text it displays, this class is needed to return
   '  the name of the font, rather than its ToString() value.
   Public Class ListBoxFontItem
      Public Font As Font

      Public Sub New(ByVal f As Font)
         Font = f
      End Sub

      Public Overrides Function ToString() As String
         Return Font.Name
      End Function
   End Class
End Class

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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