Scollable property in Listview class breaks column headers

  • Thread starter Thread starter Erik Alsmyr
  • Start date Start date
E

Erik Alsmyr

When setting the Scrollable property of a listview and resizeing it the
headers will be painted wrongly. This defect is documented in MSDN as:

In versions of the .NET Framework prior to version 2.0, the column
headers were not painted correctly when setting this property to false
and resizing the control to make it larger. To work around this issue,
set this property to true in a ResizeBegin event handler and set it
back to false in a ResizeEnd event handler.

I honestly don't understand this workaround mentioned. The ResizeBegin
and ResizeEnd event are available only on .NET framework 2.0 according
to MSDN. Does this mean the provided workaround is valid only in
versions of .NET framework where it is not needed?

Does anyone have a .NET framework 1.1 workaround around?
 
Erik Alsmyr said:
When setting the Scrollable property of a listview and resizeing it the
headers will be painted wrongly. This defect is documented in MSDN as:

In versions of the .NET Framework prior to version 2.0, the column
headers were not painted correctly when setting this property to false
and resizing the control to make it larger. To work around this issue,
set this property to true in a ResizeBegin event handler and set it
back to false in a ResizeEnd event handler.

I honestly don't understand this workaround mentioned. The ResizeBegin
and ResizeEnd event are available only on .NET framework 2.0 according
to MSDN. Does this mean the provided workaround is valid only in
versions of .NET framework where it is not needed?
Click to expand...

Yes, it sure looks that way. Even ignoring the version issue, the text is
rather strange. Why would you handle Form events to work around issues with
a control? The person that wrote that must have been drunk or something :-)
Does anyone have a .NET framework 1.1 workaround around?
Click to expand...

Found a post that suggested that something like the following might work:
private void listView_Resize(object sender, System.EventArgs e)
{
this.listView.Scrollable = true;
this.listView.Scrollable = false;
}

Haven't tried it myself though

/claes
 
I read that post and tried it but without success. Thanks for the suggestion
though.

Seems I have to meddle with the message loops and use "unsafe" code to work
around this.
 
Thought I might aswell share my solution if anyone else has run inte the
same problem...

Use the ShowScrollBar win32 API function and call it from an overridden
OnSizeChanged method in a subclassed ListView.

[DllImport("user32.dll")]
static extern bool ShowScrollBar(IntPtr hWnd, int wBar, bool bShow);

private const int SB_HORZ = 0;
private const int SB_VERT = 1;

protected override void OnSizeChanged(EventArgs e)
{
ShowScrollBar(this.Handle, SB_HORZ, false);
ShowScrollBar(this.Handle, SB_VERT, false);
base.OnSizeChanged (e);
}



This will hide the scrollbars.

I also added code to prevent columns to be resized more then the ListView
control's width.
 
Back
Top