Question

I have a form that has some controls on itself(btnCreateReport,pnlDarkLayer).I have a panel that fit to form(Dock = Fill) and it is on the back of all controls.when user click on the btnCreateReport button ,I call pnlDarkLayer BringToFront method and after some calculation I call SendToBack() method of the button.I want to draw a dark layer on form controls and disable all of controls on the form.
Is it possible? Thanks.

Maybe this code help u to understand my purpose:

private void btnCreateReport_Click(object sender, EventArgs e)
{
    pnlDarkLayer.BackColor = Color.FromArgb(100, Color.Gray);         

    pnlDarkLayer.BringToFront();
    btnCreateReport.Enabled = false;

    Thread ProcessReport = new Thread(new ThreadStart(ProcessingReport));
    ProcessReport.Start();
    while (ProcessReport.IsAlive)
    {
        Application.DoEvents();
    }
    pnlDarkLayer.SendToBack();

    btnCreateReport.Enabled = true;

}

This code hide all of controls but i don’t want to hide controls on the form.I want to draw a dark layer on them.And User must can see controls.
I need something like opacity property of forms for their controls.

I have test this:

pnlDarkLayer.CreateGraphics().CompositingMode=System.Drawing.Drawing2D.CompositingMode.SourceOver;

Update: I have test this one: (use a form instead of panel)

private void btnCreateReport_Click(object sender, EventArgs e)
{          

    btnCreateReport.Enabled = false;

    frmProgress ProgressForm = new frmProgress();
    ProgressForm.TopLevel = false;
    ProgressForm.Parent = this;
    ProgressForm.BringToFront();
    this.Controls.Add(ProgressForm);
    ProgressForm.Show();

    Thread ProcessReport = new Thread(new ThreadStart(ProcessingReport));
    ProcessReport.Start();

    while (ProcessReport.IsAlive)
    {
        Application.DoEvents();
    }
    ProgressForm.Close();
    btnCreateReport.Enabled = true;

}

But I can’t see the ProgressForm in my form.

Answer 1

From http://support.microsoft.com/kb/943454

Transparent controls in WinForms are
transparent relative to their parent,
not to other controls. Transparency in
WinForms is more akin to camouflage
than true transparency. A transparent
control doesn’t actually let you see
the control behind it through the
form. It asks its parent to draw its
own background on the “transparent”
control. This is why a transparent
control shows the form behind it, but
covers up any other controls.

To implement transparency relative to
other controls requires doing the same
thing but on a larger scale: instead
of just asking the parent to draw on
the foreground control’s background,
the control needs to ask all controls
behind it to draw on its background.
This will only work for controls which
provide some method to request that
they be drawn and will not
automatically update when the
background control’s image changes.

The page also provides a code example (in vb, sadly) to show how this is done.