TaskbarNotifier, a skinnable MSN Messenger-like Popup in C# and now in VB.NET too

John O'Byrne

4.94/5 (402 votes)

Dec 2, 2002

4 min read

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The TaskbarNotifier class allows to display an MSN Messenger-like animated popup with a skinned background

Introduction

Since I am learning C#, I thought it would be helpful for me to port my C++ CTaskbarNotifier class (http://www.codeproject.com/dialog/TaskbarNotifier.asp[^]).

As a result, I coded an MSN Messenger-like skinnable popup, with a close button which looks almost like Microsoft's one (with the associated skin).

The TaskbarNotifier class inherits from System.Windows.Forms.Form and adds a few methods to it.

Features

The MSN messenger like popup supports:

A custom transparent bitmap background
A skinnable 3-State close button
A clickable title text
A clickable content text
A selection rectangle
Custom fonts and colors for the different states of the text (normal/hover)
Animation speed parameters

Compatibility

This class is stand alone and doesn't need any particular libraries except .NET default ones. It runs in managed code and hence should be portable.

How to Use the Class

First of all, copy TaskbarNotifier.cs in your project directory.
Add on the top of your source code, the directive:
```
using CustomUIControls;
```
Add a member variable in your class:
```
TaskbarNotifier taskbarNotifier;
```

In your constructor, add the following lines:

taskbarNotifier=new TaskbarNotifier();
taskbarNotifier.SetBackgroundBitmap("skin.bmp",
                    Color.FromArgb(255,0,255));
taskbarNotifier.SetCloseBitmap("close.bmp",
        Color.FromArgb(255,0,255),new Point(127,8));
taskbarNotifier.TitleRectangle=new Rectangle(40,9,70,25);
taskbarNotifier.ContentRectangle=new Rectangle(8,41,133,68);
taskbarNotifier.TitleClick+=new EventHandler(TitleClick);
taskbarNotifier.ContentClick+=new EventHandler(ContentClick);
taskbarNotifier.CloseClick+=new EventHandler(CloseClick);

Details

taskbarNotifier.SetBackgroundBitmap("skin.bmp",
                    Color.FromArgb(255,0,255));
taskbarNotifier.SetCloseBitmap("close.bmp",
    Color.FromArgb(255,0,255),new Point(127,8));

The first line sets the background bitmap skin and transparency color (must be present), and the second line sets the 3-State close button with its transparency color and its location on the window (this line is optional if you don't want a close button).

taskbarNotifier.TitleRectangle=new Rectangle(40,9,70,25);
taskbarNotifier.ContentRectangle=new Rectangle(8,41,133,68);

These two lines allow us to define the rectangles in which will be displayed, the title and content texts.

taskbarNotifier.TitleClick+=new EventHandler(OnTitleClick);
taskbarNotifier.ContentClick+=new EventHandler(OnContentClick);
taskbarNotifier.CloseClick+=new EventHandler(OnCloseClick);

These 3 lines allow us to intercept events on the popup such as title/content or close button have been clicked

Then we are done, we just need to call:
```
taskbarNotifier.Show("TitleText","ContentText",500,3000,500);
```
This will show the popup animation with the showing/visible/hiding animations time set as 500ms/3000ms/500ms.

You can play with a few properties:

Title, content fonts and colors
Ability to click or not on the title/content/close button
You can disable the focus rect
... (see below for more details)

Class Documentation

Methods

void Show(string strTitle, string strContent, int nTimeToShow, 
                                            int nTimeToStay, int nTimeToHide)

Displays the popup for a certain amount of time.

Parameters

strTitle: The string which will be shown as the title of the popup
strContent: The string which will be shown as the content of the popup
nTimeToShow: Duration of the showing animation (in milliseconds)
nTimeToStay: Duration of the visible state before collapsing (in milliseconds)
nTimeToHide: Duration of the hiding animation (in milliseconds)

void Hide()

Forces the popup to hide.

void SetBackgroundBitmap(string strFilename, Color transparencyColor)

Sets the background bitmap and its transparency color.

Parameters

strFilename: Path of the background bitmap on the disk
transparencyColor: Color of the bitmap which won't be visible

void SetBackgroundBitmap(Image image, Color transparencyColor)

Sets the background bitmap and its transparency color.

Parameters

image: Background bitmap
transparencyColor: Color of the bitmap which won't be visible

void SetCloseBitmap(string strFilename, 
            Color transparencyColor, Point position)

Sets the 3-State close button bitmap, its transparency color and its coordinates.

Parameters

strFilename: Path of the 3-state close button bitmap on the disk (width must be a multiple of 3)
transparencyColor: Color of the bitmap which won't be visible
position: Location of the close button on the popup

void SetCloseBitmap(Image image, Color transparencyColor, Point position)

Sets the 3-State close button bitmap, its transparency color and its coordinates.

Parameters

image: Image/Bitmap object which represents the 3-state close button bitmap (width must be a multiple of 3)
transparencyColor: Color of the bitmap which won't be visible
position: Location of the close button on the popup

Properties

string TitleText (get/set)
string ContentText (get/set)
TaskbarStates TaskbarState (get)
Color NormalTitleColor (get/set)
Color HoverTitleColor (get/set)
Color NormalContentColor (get/set)
Color HoverContentColor (get/set)
Font NormalTitleFont (get/set)
Font HoverTitleFont (get/set)
Font NormalContentFont (get/set)
Font HoverContentFont (get/set)
Rectangle TitleRectangle (get/set) //must be defined before calling show())
Rectangle ContentRectangle (get/set) //must be defined before calling show())
bool TitleClickable (get/set) (default = false);
bool ContentClickable (get/set) (default = true);
bool CloseClickable (get/set) (default = true);
bool EnableSelectionRectangle (get/set) (default = true);

Events

event EventHandler CloseClick
event EventHandler TitleClick
event EventHandler ContentClick

Technical Issues

The popup is skinned using a region generated dynamically from a bitmap and a transparency color:

protected Region BitmapToRegion(Bitmap bitmap, Color transparencyColor)
{
    if (bitmap == null)
        throw new ArgumentNullException("Bitmap", "Bitmap cannot be null!");

    int height = bitmap.Height;
    int width = bitmap.Width;

    GraphicsPath path = new GraphicsPath();

    for (int j=0; j<height; j++ )
        for (int i=0; i<width; i++)
        {
            if (bitmap.GetPixel(i, j) == transparencyColor)
                continue;

            int x0 = i;

            while ((i < width) && 
                    (bitmap.GetPixel(i, j) != transparencyColor))
                i++;

            path.AddRectangle(new Rectangle(x0, j, i-x0, 1));
        }

    Region region = new Region(path);
    path.Dispose();
    return region;
}

The refresh() of the popup is done using the double buffering technique to avoid flickering:

protected override void OnPaintBackground(PaintEventArgs pea)
{
    Graphics grfx = pea.Graphics;
    grfx.PageUnit = GraphicsUnit.Pixel;

    Graphics offScreenGraphics;
    Bitmap offscreenBitmap;

    offscreenBitmap = new Bitmap(BackgroundBitmap.Width, 
                                BackgroundBitmap.Height);
    offScreenGraphics = Graphics.FromImage(offscreenBitmap);

    if (BackgroundBitmap != null)
    {
        offScreenGraphics.DrawImage(BackgroundBitmap, 
            0, 0, BackgroundBitmap.Width, BackgroundBitmap.Height);
    }

    DrawCloseButton(offScreenGraphics);
    DrawText(offScreenGraphics);

    grfx.DrawImage(offscreenBitmap, 0, 0);
}

Bugs/Limitations

Since I wanted to keep only managed code, I used the Screen.GetWorkingArea(WorkAreaRectangle) function instead of using unmanaged code to get the taskbar position. As a result, I made the popup always appear at the bottom of WorkAreaRectangle whichever position the taskbar has.

I didn't find any C# managed equivalent to the Win32 function ShowWindow(SW_SHOWNOACTIVATE) to make the popup, not steal the focus of the active window.

Updates

01 April, 2003: Small bug fix in the OnMouseUp handler
11 January, 2003: Patrick Vanden Driessche updated both the C# and VB.NET versions:
- The popup now doesn't close automatically when the mouse is still over it
- The popup is shown again when it was disappearing and the mouse comes over it
- A few other bugs have been corrected
10 January, 2003: A port of TaskbarNotifier has been done by Patrick Vanden Driessche in VB.NET
05 December, 2002: The popup is now shown using the Win32 function ShowWindow(SW_SHOWNOACTIVATE), to prevent the popup from stealing the focus.

Conclusion

I hope this code will be useful to you. If you have suggestions to enhance this class functionalities, please post a comment.

License

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