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VB.net Transparent ListView

Hi All,

VS2008

I'm using the transparent listview code from here (http://www.vbforums.com/showthread.php?t=597891) (unmodified)
and am adding the TLV to a TabControl that has a background image (which is why i want to use the transparency)

I'm having two problems with it.

1) when it is populated the background is black, not transparent.  setting the .BackColor = Color.Transparent gives an error that it is not supported. (Changing the .BackColor to anything else doesn't change it from black)

2) I changed the .HighlightColor to Color.Tomato (the same happens for all other colors as well), and the rows stay highlighted, but the text becomes garbled after you click on the 2nd or third row (or scroll).

#1 is the more important one for now

Any suggestions?
Private WithEvents NewsList as TransparentListView

Public Sub New()
        InitializeComponent()
        NewsList = New TransparentListView
        With NewsList
            .Size = New Size(801, 219)
            .Location = New Point(100, 169)
            .View = View.Details
            .MultiSelect = False
            .FullRowSelect = True
            .ContextMenuStrip = NewsContext
            .BackColor = Color.Blue
            .HighlightColor = Color.Tomato
        End With
        OverviewTab.Controls.Add(NewsList)

End Sub

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sgaggerj
Asked:
sgaggerj
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1 Solution
 
Bob LearnedCommented:
If you really want my suggestion, then I would say that you don't have something that is designed well, and you might want to think about a different approach.  I don't see enough detail about how to use the control, and the internal refresh timer doesn't sound like a very good idea.
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sgaggerjAuthor Commented:
yea I think I was wowed by the demo image as that's essentially the effect i wanted.

any suggestions on where to look for pre-built code (i've been googling like crazy), or where/how to start?  

What would you do to implement this feature?
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Bob LearnedCommented:
Can you attach a .png screen shot of what you are trying to achieve, and how it is working.  There might be an easier way to achieve the effect that you need, but I am not quite sure how it is working now...
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sgaggerjAuthor Commented:
This project is a side project at the moment.  It's a PC app for games that are played on the iPhone.  Though it seems like the company has shut down their servers so this may be moot for this project, but i'd still like to do it.

unfortunately, because their servers are offline my app is no longer functional so i can't give a screenshot of what i was doing at the moment.
i'll describe it as best i can.

i have a tab page that has a background image stretched to fill the entire tab page.
i have a listview control that is about 1/3 of the area of the tab page.

i want the listview to be transparent so that the background image is obscured ONLY by the text contained in the listview.

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Bob LearnedCommented:
I have been on vacation for a while, and I just noticed that I hadn't gotten back to this question.  I came up with something that might work, but I don't have access to that code now.  I will need to show you what I have, and see if it meets your requirements.  
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sgaggerjAuthor Commented:
i'd love to take a look at it.  thanks!

(sorry for the late reply, i've been plugging away at my primary project)
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Bob LearnedCommented:
Here is the code (and screen shot):


Imports System.Runtime.InteropServices
Imports System.Windows.Forms

Namespace CodeSnippets

    Public Class TransparentListView
        Inherits ListView

        Public Sub New()
            Me.OwnerDraw = True
            Me.DoubleBuffered = True
        End Sub

        Protected Overrides Sub OnDrawItem(ByVal e As DrawListViewItemEventArgs)
            TextRenderer.DrawText(e.Graphics, e.Item.Text, e.Item.Font, Me.UpdateBounds(e.Item, e.Bounds, True), Color.Red, 0)
        End Sub

        Protected Overrides Sub CreateHandle()
            MyBase.CreateHandle()

            UnsafeNativeMethods.SendMessage(Me.Handle, UnsafeNativeMethods.LVM_SETBKCOLOR, 0, UnsafeNativeMethods.CLR_NONE)
        End Sub

        Private Overloads Function UpdateBounds(ByVal item As ListViewItem, ByVal originalBounds As Rectangle, ByVal drawText As Boolean) As Rectangle
            Dim rectangle As Rectangle = originalBounds
            If (item.ListView.View = View.Details) Then
                If (Not item.ListView.FullRowSelect AndAlso (item.SubItems.Count > 0)) Then
                    Dim subItem As ListViewItem.ListViewSubItem = item.SubItems(0)
                    Dim size As Size = TextRenderer.MeasureText(subItem.Text, subItem.Font)
                    rectangle = New Rectangle(originalBounds.X, originalBounds.Y, size.Width, size.Height)
                    rectangle.X = (rectangle.X + 4)
                    rectangle.Width += 1
                Else
                    rectangle.X = (rectangle.X + 4)
                    rectangle.Width = (rectangle.Width - 4)
                End If
                If drawText Then
                    rectangle.X -= 1
                End If
            End If
            Return rectangle
        End Function

        Private Class UnsafeNativeMethods
            Friend Const CLR_NONE As Integer = -1
            Friend Const LVM_FIRST As Integer = &H1000
            Friend Const LVM_SETBKCOLOR As Integer = LVM_FIRST + 1

            <DllImport("user32.dll", CharSet:=CharSet.Auto)> _
            Friend Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As IntPtr
            End Function
        End Class

    End Class

End Namespace

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Screenshot.png
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sgaggerjAuthor Commented:
Narf!

Thanks - i'll take a look and give it a whirl as soon as i can,  looks like it is exactly what i was trying to do.
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sgaggerjAuthor Commented:
Works great! Thanks!!
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