Graphics

Re: Making sure my my custom control is always on top

28-Jan-08 3:09

I have a custom control that i am able to change its opacity. In my client application, i have a picture box that i use to view the video from my web cam.

The problem is that, my custom control has refused to sit on to of the picture box. At design time and at runtime when my web can is shut down i can see it on top of the picture box; but at runtime when the web cam transmits its video to the picture box, the control goes below the picture box.

I want my control to always sit on top, can someone help me.

Mark Salsbery28-Jan-08 7:12

Re: Making sure my my custom control is always on top

28-Jan-08 7:12

Initially, Z-order is determined by the order the controls are
created (assuming they have the same parent). What order do you
create the controls?

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Sampson Orson Jackson28-Jan-08 20:33

Re: Making sure my my custom control is always on top

28-Jan-08 20:33

I have not tried setting the z-order yet.

One thing i would like to stress on is that, when i place the default .net panel on the video viewer(picturebox with realtime image from the webcam) the panel remains on top. But with my custom semi-transparent panel, the video viewer over laps the custom panel.

I have a feeling that there is a/some lines of code im missing out in my custom panel.

I just found out that my semi-transparent panel can not display background images.

This is the code for the semi-transparent panel:
<code>
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;

using System.Drawing.Drawing2D;
using System.Drawing;

namespace VideoCapture_Tutorial
{
public partial class MyControl : Panel
{
private Color brushColor;

public MyControl()
{
InitializeComponent();
}

public MyControl(IContainer container)
{
container.Add(this);

InitializeComponent();
}

protected override CreateParams

CreateParams
{
get
{
CreateParams createParams =

base.CreateParams;
createParams.ExStyle |=

0x00000020; // WS_EX_TRANSPARENT
return createParams;
}
}

protected override void

OnPaintBackground(PaintEventArgs e)
{
//
}

protected override void

OnPaint(PaintEventArgs e)
{
Graphics graphics = e.Graphics;
Rectangle rect = new Rectangle(0, 0,

base.Width - 1, base.Height - 1);
Color brushColor = this.brushColor;
Pen pen = new Pen(Color.Black);
int num = (10 * 0xff) / 100;
SolidBrush brush = new

SolidBrush(Color.FromArgb(num, brushColor));
graphics.FillRectangle(brush, rect);
graphics.DrawRectangle(pen, rect);
pen.Dispose();
brush.Dispose();
graphics.Dispose();

//Invalidate();
}

public Color BrushColor
{
get
{
return this.brushColor;
}
set
{
this.brushColor = value;
base.RecreateHandle();
}
}

//protected override void

}
}
</code>

Thanks for your help. I guess you can still do more it is really urgent.

Thanks

Sampson Orson Jackson28-Jan-08 20:34

Re: Making sure my my custom control is always on top

28-Jan-08 20:34

I have not tried setting the z-order yet.

One thing i would like to stress on is that, when i place the default .net panel on the video viewer(picturebox with realtime image from the webcam) the panel remains on top. But with my custom semi-transparent panel, the video viewer over laps the custom panel.

I have a feeling that there is a/some lines of code im missing out in my custom panel.

This is the code for the semi-transparent panel:
<code>
using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Windows.Forms;

using System.Drawing.Drawing2D;
using System.Drawing;

namespace VideoCapture_Tutorial
{
public partial class MyControl : Panel
{
private Color brushColor;

public MyControl()
{
InitializeComponent();
}

public MyControl(IContainer container)
{
container.Add(this);

InitializeComponent();
}

protected override CreateParams

CreateParams
{
get
{
CreateParams createParams =

base.CreateParams;
createParams.ExStyle |=

0x00000020; // WS_EX_TRANSPARENT
return createParams;
}
}

protected override void

OnPaintBackground(PaintEventArgs e)
{
//
}

protected override void

OnPaint(PaintEventArgs e)
{
Graphics graphics = e.Graphics;
Rectangle rect = new Rectangle(0, 0,

base.Width - 1, base.Height - 1);
Color brushColor = this.brushColor;
Pen pen = new Pen(Color.Black);
int num = (10 * 0xff) / 100;
SolidBrush brush = new

SolidBrush(Color.FromArgb(num, brushColor));
graphics.FillRectangle(brush, rect);
graphics.DrawRectangle(pen, rect);
pen.Dispose();
brush.Dispose();
graphics.Dispose();

//Invalidate();
}

public Color BrushColor
{
get
{
return this.brushColor;
}
set
{
this.brushColor = value;
base.RecreateHandle();
}
}

//protected override void

}
}
</code>

Thanks for your help. I guess you can still do more it is really urgent.

Thanks

Mark Salsbery29-Jan-08 5:18

Re: Making sure my my custom control is always on top

29-Jan-08 5:18

Orson wrote:
I have not tried setting the z-order yet.

But that's what determines what gets drawn on top of what Smile | :)

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Mark Salsbery29-Jan-08 5:22

Re: Making sure my my custom control is always on top

29-Jan-08 5:22

How do the video frames get drawn on the picture box?

Since video frames are being drawn periodically, you'll also
need to redraw any overlaid controls each time a frame is drawn.

Of course, this will flicker....you'll probably have to deal with
that as well.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Sampson Orson Jackson29-Jan-08 6:21

Re: Making sure my my custom control is always on top

29-Jan-08 6:21

What event do i override for the picture box(video viewer) for repainting the picture box?

How do implement the z-order?

Sorry im asking to many questions, i just came into c# im from a java background.

Mark Salsbery29-Jan-08 7:46

Re: Making sure my my custom control is always on top

29-Jan-08 7:46

Orson wrote:
What event do i override for the picture box(video viewer) for repainting the picture box?

The Paint event? I'm still unclear as to how the video is being drawn
on your picture box. What control are you using?

Orson wrote:
How do implement the z-order?

You can change the z-order of controls on a form using the
Control.ControlCollection.SetChildIndex Method[^]

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Sampson Orson Jackson29-Jan-08 21:26

Re: Making sure my my custom control is always on top

29-Jan-08 21:26

Im using the avicap32 and user32 dll's of windows to preview my video from the webcam to my picture box.

The code fragment from different layers on my application that previews the video in the picture is displayed below:

<br />
        private void lstVideoSources_SelectedIndexChanged(object sender, EventArgs e)<br />
        {<br />
            Device d = DeviceManager.GetDevice(lstVideoSources.SelectedIndex);<br />
            d.ShowWindow(this.video_viewer);<br />
        }<br />
<br />
//The methods below is from the device class<br />
<br />
<br />
        /// <summary><br />
        /// Shows the webcam preview in the control<br />
        /// </summary><br />
        /// <param name="windowsControl">Control to attach the webcam preview</param><br />
        public void ShowWindow(global::System.Windows.Forms.Control windowsControl)<br />
        {<br />
            Init(windowsControl.Height, windowsControl.Width, windowsControl.Handle.ToInt32());<br />
        }<br />
<br />
<br />
        /// <summary><br />
        /// To Initialize the device<br />
        /// </summary><br />
        /// <param name="windowHeight">Height of the Window</param><br />
        /// <param name="windowWidth">Width of the Window</param><br />
        /// <param name="handle">The Control Handle to attach the device</param><br />
        public void Init(int windowHeight, int windowWidth, int handle)<br />
        {<br />
            string deviceIndex = Convert.ToString(this.index);<br />
            deviceHandle = capCreateCaptureWindowA(ref deviceIndex, WS_VISIBLE | WS_CHILD, 0, 0, windowWidth, windowHeight, handle, 0);<br />
<br />
            if (SendMessage(deviceHandle, WM_CAP_DRIVER_CONNECT, this.index, 0) > 0)<br />
            {<br />
                SendMessage(deviceHandle, WM_CAP_SET_SCALE, -1, 0);<br />
                SendMessage(deviceHandle, WM_CAP_SET_PREVIEWRATE, 0x42, 0);<br />
                SendMessage(deviceHandle, WM_CAP_SET_PREVIEW, -1, 0);<br />
<br />
                SetWindowPos(deviceHandle, 1, 0, 0, windowWidth, windowHeight, 6);<br />
            }<br />
        }<br />

Im trying out what you said...

Sampson Orson Jackson29-Jan-08 21:55

Re: Making sure my my custom control is always on top

29-Jan-08 21:55

Can i send you the entire code through your mail box please?

Sampson Orson Jackson29-Jan-08 22:30

Re: Making sure my my custom control is always on top

29-Jan-08 22:30

I just noticed something. I tried to change the z-order and position(left,top) on the click event of the picturebox, but each time i click on the picture box while the video is on it, nothing happens. but when i stop the video(i.e when picturebox is now like normal without images) and click on the picturebox the action specified in the click event takes place.

I feel the video is like a different layer on top of the picture box.

Another important note is that the video also works on a panel.

Mark Salsbery30-Jan-08 5:33

30-Jan-08 5:33

Orson wrote:
I feel the video is like a different layer on top of the picture box

In a way, it is. You won't be able to draw on the top of live video because
every new frame gets drawn on top of whatever you draw there. Changing the z-order
will not help here - VFW still just draws to the screen.

To get around this, you need (ideally) to be able to draw on a video frame before
it is drawn to the screen. This will prevent the flicker associated with redrawing
any overlay over the top of every video frame on the screen.
With VFW, capSetCallbackOnVideoStream() can help.

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

.x models

Omar Gameel Salem26-Jan-08 12:47

Omar Gameel Salem

26-Jan-08 12:47

hey guys..anyone knows a good website to download .x models to use with directx 9?
thank you Wink | ;)

Pete O'Hanlon28-Jan-08 9:44

Pete O'Hanlon

28-Jan-08 9:44

There's http://www.3-d-models.com/[^].

Deja View - the feeling that you've seen this post before.

My blog | My articles

Jeremy Falcon6-Feb-08 10:25

Jeremy Falcon

6-Feb-08 10:25

http://www.3dcafe.com/[^]

You and convert other formats to X as well. So, don't let the format alone stop you. Wink | ;)

Jeremy Falcon
Oatmeal, It's What's for Dinner.[^]

Omar Gameel Salem7-Feb-08 7:55

Omar Gameel Salem

7-Feb-08 7:55

thanks guys..but maybe i should have mentioned i want FREE sites ?:P

Pete O'Hanlon7-Feb-08 11:59

Pete O'Hanlon

7-Feb-08 11:59

How about here[^]? You can easily convert these into .X models using a model converter.

Deja View - the feeling that you've seen this post before.

My blog | My articles