Update: Added section on the special case of the ‘Games’ folder and how to setup PNG Start screen icons there.
Update: As of August 10, 2009, the requirement for the PNG Start Screen icons has changed from requiring three to one (90x90) PNG icon. This post has been updated to reflect this change. You can satisfy this requirement via the static setup described below.

If you’ve seen the any of the plethora of Windows Mobile 6.5 screen shots, likely you’d agree that it looks much better than previous versions. A component of this ‘face lift’, is support for PNG files in the Window Mobile 6.5 Start screen. Including a nicely rendered PNG file as your application icon is important to ensure the highest quality user experience across different devices.

If you plan to distribute your application via Windows Marketplace for Mobile (and I don’t know why you wouldn’t) the requirements document requires that you use a 90 x 90 Start screen icon for your application. This post will cover how to use PNG files as icons in the Windows Mobile 6.5 Professional Start screen. For information on creating PNG icons, see my previous post on Creating Custom Icons for Windows Mobile 6.5. The sample code I will be referring to in this post can be found here.

Contents:

Start Screen: Resolution / DPI and Icon Size
Registry Keys
Setup: Static or Dynamic
Cached Icons
Games Shortcuts Folder

Start Screen: Resolution / DPI and Icon Size

The Start Screen is one of the huge improvements in Windows Mobile 6.5 Professional. This replaces the Start Menu in previous versions. The improvements include: enhanced touch screen navigation (tap, tap and hold, pan, and flick) and more options for organizing and presenting Start menu items.

If you are an experienced Windows Mobile developer, you know that depending on the DPI and resolution of the device, the shell extracts the appropriately sized icon from the EXE for display in the Start screen. Windows Mobile 6.5 still supports this; however now it also supports the display of PNG file icons. The shell does not automatically select the size of the PNG icon based on the device DPI. This dynamic selection of the icon is done in a setup dll. (See dynamic setup below.) However, if you do not want to provide a separate PNG file for each DPI, you can provide one (90x90) and the shell will scale down the icon as necessary, depending on the DPI of the device. (In fact, this is the Marketplace requirement.) The table below illustrates the DPI / resolution and icon size relationship. 

Registry Keys

To have the Start screen use a PNG file instead of an icon embedded in the EXE, you need to provide the following registry entries:

[HKEY_LOCAL_MACHINE\Security\Shell\StartInfo\Start\Phone.lnk]
"Icon"="\Application Data\My App\newphoneicon.png"

Here are the definitions of the value pair settings:

Setup

In the next two sections, I’ll walk through two deployment scenarios, static and dynamic.

Static Setup:

You can specify the registry key as part of your CAB file configuration. Per the Marketplace requirements, I will use a 90 x 90 PNG file as the Start screen icon. In my Smart Device CAB project, I have added the following registry key:

Note: This registry key supports ‘CE strings’ and .INF file strings. Above %InstallDir% maps to the ‘\Program Files\SMS Intercept’ directory.

My CAB file also includes the (90x90) AppIcon.png and a shortcut of the same name as the registry key above (SMS Intercept.lnk). See below:

Dynamic Setup:

Detecting DPI:

Another way to configure the Start screen icon is dynamically: copying the appropriately sized PNG file based on the DPI of the device. We will use a setup dll to detect the DPI, and copy the appropriate PNG. You may know that WCELOAD (the EXE that process the CAB file) or a DLL that is loaded into its process, will return the same DPI (96) no matter the actual DPI of the device. To workaround this, we launch a very small helper EXE that quickly exits, without UI, and returns the DPI. The SDK sample ResDLL uses this technique as well as demonstrates how to install DPI specific resource DLLs. Here is the code used to detect the DPI:

int WINAPI WinMain( HINSTANCE hInstance,
                    HINSTANCE hPrevInstance,
                    LPTSTR    lpCmdLine,
                    int       nCmdShow)
{
    HDC hdc = ::GetDC(NULL);
    INT ans = ::GetDeviceCaps(hdc, LOGPIXELSX);
    ::ReleaseDC(NULL, hdc);
    return ans;
}

Copy DPI specific files:

Our dynamic CAB file contains four png files:
        45.png
        60.png
        90.png
        AppIcon.png

Based on the DPI detected, we copy the appropriate PNG file to the filename AppIcon.png. AppIcon.png is included in the CAB as a fallback in case our DPI detect logic fails. The unused icons and the DPI detect EXE are deleted.

Here is a code snippet from the sample setup dll (SetupDPI) implementing this:

wsprintf(szFile,_T("%s\\%s"), pszInstallDir, _T("\\GetRealDPI.EXE"));
// Launch DPI Detector
::CreateProcess(szFile, NULL, NULL, NULL, NULL, 0, NULL, NULL, NULL, &pi);
::WaitForSingleObject(pi.hProcess, 10000);
// DPI is returned in exit code of detector app
::GetExitCodeProcess(pi.hProcess, &nSystemDPI);
::CloseHandle(pi.hProcess);
::DeleteFile(szFile);

// Based on DPI, copy xx.png to AppIcon.png and delete unused files
wsprintf(szOutFile,_T("%s\\%s"), pszInstallDir, szTargetFilename);
for (INT i=0;i<ARRAYSIZE(DPI_Icon);i++) {
    wsprintf(szFile,_T("%s\\%s"), pszInstallDir, DPI_Icon[i].lpstrIconSize);
    if (DPI_Icon[i].DPI==nSystemDPI) {
        ::CopyFile(szFile, szOutFile, FALSE);
    } 
    ::DeleteFile(szFile);
}

Create Shortcut:

As mentioned, we do the post-processing of the files after the CAB is installed (in the Install_Exit function). That is, because the icon image in the Start screen is created when the shortcut is created (see the cached icons section below), we need to create the shortcut in the setup dll instead of in the CAB file as was done in the static CAB sample. Otherwise, the Start screen will use an icon extracted from the EXE instead of the PNG file. Here is the language independent code that creates the shortcut:

// Build lnk filename
PTCHAR pAppDir = wcsrchr(pszInstallDir, '\\');
TCHAR szShortcutPath[MAX_PATH];
// CSIDL_PROGRAMS == \Windows\Start Menu\Programs
SHGetSpecialFolderPath(hwndParent, szShortcutPath, CSIDL_PROGRAMS , false); 
wsprintf(szFile,_T("%s%s%s"), szShortcutPath, pAppDir, _T(".lnk"));

// Build exe filename
// CSIDL_PROGRAM_FILES == \Program Files
SHGetSpecialFolderPath(hwndParent, szShortcutPath, CSIDL_PROGRAM_FILES  , false); 
wsprintf(szOutFile,_T("\"%s%s%s%s\""), 
     szShortcutPath, pAppDir, pAppDir, _T(".exe"));

SHCreateShortcut(szFile, szOutFile);

Cached Icons

During development, you will likely want to change the PNG file as you experiment will different artwork. You will notice that if you overwrite the PNG file, the Start screen will not use the new image. This is because when the Start screen shortcut is created, the icon image is cached by the shell. Thereafter for better performance, the shell retrieves the image from the cache. The cache is rebuilt a boot time. Here is one possible workaround:

1. Delete the shortcut
2. Rename (or copy) target EXE name. For example, rename hello.exe to hello1.exe
3. Recreate shortcut pointing to new EXE name.

Here is provisioning XML that does this. You can run this using RapiConfig.exe:

<wap-provisioningdoc>
<characteristic type="FileOperation">
  <!-- Delete Shortcut -->
  <characteristic type="%CE11%\SMS Intercept.lnk" translation="install">
    <characteristic type="Delete">
    <parm name="ForceDelete"/>
    </characteristic>
  </characteristic>

<!-- Copy EXE name to new EXE -->
    <characteristic type="%CE1%\sms Intercept\sms Intercept1.exe" 
          translation="install">
    <characteristic type="Copy">
    <parm name="Source" value="%CE1%\sms Intercept\sms Intercept.exe" 
          translation="install"/>
    </characteristic>
  </characteristic>

<!-- Create new shortcut pointing to new EXE name -->
    <characteristic type="%CE11%" translation="install">
    <characteristic type="MakeDir" /> 
      <characteristic type="SMS Intercept.lnk" translation="install">
        <characteristic type="Shortcut">
        <parm name="Source" value="%CE1%\sms Intercept\sms Intercept1.exe" 
              translation="install" /> 
        </characteristic>
      </characteristic>
    </characteristic>
</characteristic>
</wap-provisioningdoc>

Games Shortcuts Folder

[HKEY_LOCAL_MACHINE\Security\Shell\StartInfo\Start\Games\Phone.lnk]
"Icon"="\Application Data\My App\newphoneicon.png"

// Set this to true to create shortcut and 
// registry key in the localized 'Games' Folder
BOOL g_bCreateInGamesFolder=FALSE;

Conclusion

You should now understand how to configure your CAB file projects to include PNG files as icons in the Windows Mobile 6.5 Start screen.

For a list of frequently asked questions on this topic see here: Start Screen PNG Icon FAQ

This small set of Vista icons are perfect for any business type of desktop. I don’t know why this set if perfect for business but it just is. It might be the grey tones or the sleek look of the icons, either way I really like this set. My favorite is the network icon.

Title: Desktop
Author: Cheezen
Download: Desktop Icons Pack

1. Open up Folder Options again by clicking My Computer. Then when it launches, click the Tools menu bar entry and select Folder Options.
2. Inside Folder Options, click the File Types tab to reveal the list of all of the different file extensions on your computer.
3. Browse through the list and select the extension for which you want to change the icon.
4. Once you have the entry selected, click the Advanced button.

5. On the Edit File Type screen, click the Change Icon button, as shown in Figure below.

6. The Change Icon screen will be displayed.Here, you will be shown various system icons from which you can choose.If you do not find any that you like, just click the Browse button and select an icon that you downloaded on your computer.
7. Once you find the perfect icon,click OK to select the new icon.
8. Then click OK once more to save your changes.

You can never have too many Vista icons to choose from so here are some more great icons to add to your computer. These icons are simple but full of color and would look great on any desktop. I like the Office documents icons the best. I wish Microsoft would have made these beautiful creations the default Vista icons.

Title: Windows
Author: SaviourMachine
Download: Windows Icons Pack

There aren’t too many gold colored Vista icons but I managed to find some of the best. This set of icons is very high class and would wonderfully decorate any desktop within seconds. I like the My Computer icon the best.

Title: Le Esta
Author: gakuseisean
Download: Le Esta Icons Pack

With all the recent news about airplanes I thought that I’d include some classic aviation icons today. The detail, color and uniqueness of these Vista icons are simply the best. My favorite is the parachute. I think more people should consider changing the icons on their desktops because it really adds so much.

Title: Aviation
Author: Iconshock
Download: Aviation Icons Pack