[RESOLVED] Font Size Issue With Custom Created Listbox Control

[hackerspk]

I am try to Inherits a Listbox control to change StringFormatFlags direction. All is OK, but when I change the font size of Listbox control it dose not draw item properly. How to fix this issue. I am stuck with this problem from many days.

Public Class UrduListBox
    Inherits ListBox
    Public Sub New()
        Me.DrawMode = DrawMode.OwnerDrawVariable
        AddHandler Me.DrawItem, AddressOf Draw_DrawItem
    End Sub
    Public Sub Draw_DrawItem(ByVal sender As Object, ByVal e As DrawItemEventArgs)
        Try
            Dim sf As New StringFormat()
            If sender.RightToLeft = Windows.Forms.RightToLeft.Yes Then
                sf.FormatFlags = StringFormatFlags.DirectionRightToLeft
            End If
            Dim br As New SolidBrush(sender.ForeColor)
            If (e.State And DrawItemState.Selected) = DrawItemState.Selected Then
                e.DrawBackground()
                br = Brushes.White
            Else
                e.Graphics.FillRectangle(New SolidBrush(e.BackColor), e.Bounds)
                br = Brushes.Black
            End If
            Using fnt As New Font(sender.Font.Name.ToString(), sender.Font.Size.ToString(), FontStyle.Regular, GraphicsUnit.Point)
                e.Graphics.DrawString(sender.Items(e.Index).ToString(), fnt, br, e.Bounds, sf)
            End Using
        Catch ex As Exception

        End Try
    End Sub 

[Edgemeal]

All is OK, but when I change the font size of Listbox control it dose not draw item properly. How to fix this issue. I am stuck with this problem from many days.

Honestly I'm not sure but I've seen posts that include OnMeasureItem that supposedly fix that sort of thing, quick test,...

Public Class UrduListBox
    Inherits ListBox

    Public Sub New()
        Me.DrawMode = DrawMode.OwnerDrawVariable
    End Sub

    Protected Overrides Sub OnMeasureItem(e As MeasureItemEventArgs)
        MyBase.OnMeasureItem(e)
        Dim ItemSize As SizeF = e.Graphics.MeasureString(Me.Items(e.Index).ToString, Me.Font, Me.ClientSize.Width)
        e.ItemHeight = Size.Round(ItemSize).Height
    End Sub

    Protected Overrides Sub OnDrawItem(e As DrawItemEventArgs)
        MyBase.OnDrawItem(e)
        e.DrawBackground()
        Dim sf As New StringFormat(CType(Me.RightToLeft, StringFormatFlags))
        Dim br As New SolidBrush(Me.ForeColor)
        If (e.State And DrawItemState.Selected) = DrawItemState.Selected Then
            br.Color = Color.White
        End If
        e.Graphics.DrawString(Me.Items(e.Index).ToString, Me.Font, br, e.Bounds, sf)
        e.DrawFocusRectangle()
    End Sub

End Class

[hackerspk]

I think it can do the thing but there is a problem:

[jmcilhinney]

You probably just need to test that there's an item at the specific index, i.e. that the index is less than Items.Count, in the OnMeasureItem method.

[hackerspk]

got it. thanks it is working.