Moving a form and a panel in parallel should not be as difficult ?!?!?!?

[gourmete]

Hi!

I´m developing a screen-capture application.
My Idea is to cover the whole screen with a semi-transparent
clickt-hrough layer, solely the Area that will be captured should
appear without this layer.

What I did:
I use two forms.
The first form works as the background-layer. It has no border and
covers the whole screen. Opacity is set and the ex.Style ist
WS_EX_TRANSPARENT to make it click-through. On this Form I have a panel
wich backcolor is set to the forms transparency-key, hence we can look
through the panels area.
Second form is not click-through, because i need controls on it. There
is also an transparent panel on it, which refers to the area to be
captured. When moving and resizing this form I map position and size
of both forms transparent panels.
The way it works is exactly what I had in mind, but there is one
problem: When moving the front-form I update the location of the
transparent panel on the back-form. This update takes to much time, i.
e. the second panel moves two slow.
Does anyone can give me an hint how I can move my front-form and the
transparent-panel on the back-form in exactly the same time. I read
about the DeferWindowPos Win32 Methods, but I didn´t get it work.

Since I think nobody understood what I´m talking about I´ll provide
some code:

----------------------------------------------BACK-FORM--------------------------------------------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace transp
{
public class Back : Form
{
private System.ComponentModel.IContainer components = null;
private Panel transparentArea;
public const int WS_EX_TRANSPARENT = 32;

protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

private void InitializeComponent()
{
this.transparentArea = new System.Windows.Forms.Panel();
this.SuspendLayout();
//
// transparentArea
//
this.transparentArea.BackColor =
System.Drawing.Color.Fuchsia;
this.transparentArea.Location = new
System.Drawing.Point(40, 73);
this.transparentArea.Name = "transparentArea";
this.transparentArea.Size = new System.Drawing.Size(200,
100);
this.transparentArea.TabIndex = 0;
//
// Back
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F,
13F);
this.AutoScaleMode =
System.Windows.Forms.AutoScaleMode.Font;
this.BackColor = System.Drawing.Color.LightSlateGray;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.transparentArea);
this.FormBorderStyle =
System.Windows.Forms.FormBorderStyle.None;
this.Name = "Back";
this.Opacity = 0.8;
this.Text = "Form1";
this.TopMost = true;
this.TransparencyKey = System.Drawing.Color.Fuchsia;
this.ResumeLayout(false);
}

public Back()
{
InitializeComponent();
this.Bounds = SystemInformation.VirtualScreen;
}

public Rectangle TransparentAreaBounds
{
get { return this.transparentArea.Bounds; }
set { this.transparentArea.Bounds = value; }
}

protected override CreateParams CreateParams
{
get
{
//make it click-through
CreateParams cp = base.CreateParams;
cp.ExStyle |= WS_EX_TRANSPARENT;
return cp;
}
}
}
}
--------------------------------------------------------------------------------------------------------------------------


----------------------------------------------FRONT-FORM-------------------------------------------------------
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace transp
{
public class Front : Form
{
private System.ComponentModel.IContainer components = null;
private Back backGroundForm = null;

protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

private void InitializeComponent()
{
this.SuspendLayout();
this.AutoScaleDimensions = new System.Drawing.SizeF(6F,
13F);
this.AutoScaleMode =
System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(292, 266);
this.FormBorderStyle =
System.Windows.Forms.FormBorderStyle.SizableToolWindow;
this.Name = "Front";
this.Text = "Front";
this.ResumeLayout(false);
}

public Front()
{
InitializeComponent();
this.TopMost = true;
this.BackColor = Color.Fuchsia;
this.TransparencyKey = Color.Fuchsia;
this.Move += new EventHandler(UpdateBackGround);
this.Resize += new EventHandler(UpdateBackGround);
backGroundForm = new Back();
this.Show();
backGroundForm.Show();
backGroundForm.TransparentAreaBounds = this.Bounds;

}

void UpdateBackGround(object sender, EventArgs e)
{
backGroundForm.TransparentAreaBounds = this.Bounds;
}

[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Front());
}
}
}

 

[Michael C]

problem: When moving the front-form I update the location of the
transparent panel on the back-form. This update takes to much time, i.
e. the second panel moves two slow.

Transparancies are slow becuase the background needs to be redrawn
(presumably in a buffer) and then the transparent form needs to be drawn.
Most transparancies that are used by windows are fairly restricted in size.
I suspect you need to find a better way to do this.

Michael

 

[gourmete]

Hi!

Thanks for your reply! I think you are right. I coded the moving in an
plenty of ways but the same *** problem anyway.
Do you think using .NET 3.0 with WPF can give better results? Vista is
dealing with transparency all over the place, thus they probably
improved the underlying mechanisms?! If so, does anyone know if the
required features would do their work on XP SP2 as well?

Thank you!