Bruce Eitman

Windows CE: Using RAPI to Run Applications (Part 2)

2009-10-30T15:24:04-12:00:00

The CERunApp application can be downloaded from:

The CERunApp source code can be downloaded from:

In Windows CE: Using RAPI to Run Applications (Part 1) I wrote about starting this project to create a copy of the Windows Mobile Developer Power Toys application RAPIStart. In this article I will continue by creating an slight twist on RAPIStart.

As I discussed in Part 1, I decided that simply reproducing RAPIStart wasn’t all that exciting, since the source code for a similar app is available in the Windows Mobile SDK. So in this article I will develop a GUI based application that not only starts an app on a Windows CE device from a connected workstation, but will also transfer the app to the device before running it. I will show the interesting code here, but the link at the top of this page leads you to the download of the code and the app itself.

Since this is a GUI based app, I developed it using C#. This choice meant that I spent very little effort on the GUI and was able to focus on the RAPI pieces.

The user interface looks like this:

This simple dialog contains:

1. A text box to enter the application to run on the Windows CE device

2. A browse button that opens a System.Windows.Forms.OpenFileDialog to select a file

3. A text box to enter command line options

4. A button to request that the app be downloaded to and run on the Windows CE device

Simple enough, and it requires very little code to back it up if we ignore the RAPI bits. Basically there are two functions, one each for the buttons. That code is:

private void FileBrowseButton_Click(object sender, EventArgs e)

{

if (DialogResult.OK == openFileDialog1.ShowDialog())

{

AppName.Text = openFileDialog1.FileName;

}

private void RunApplicationButton_Click(object sender, EventArgs e)

{

CRapi RAPI = new CRapi();

if(RAPI.CeCopyToDevice(AppName.Text, "\\" + openFileDialog1.SafeFileName))

RAPI.CeRunApplication("\\" + openFileDialog1.SafeFileName, CommandLineOptions.Text);

else

System.Windows.Forms.MessageBox.Show("Unable to copy file to the Windows CE");

}

The browse button handler, FileBrowseButton_Click(), simply calls on the OpenFileDialog class to show the dialog. If it succeeds, then fill in the text box with the file path and name.

The run applciation handler, RunApplicationButton_Click() uses a CRapi class that I will show next to copy the file to the Windows CE Device and then start the application.

The CRapi class is the meat of this application. It knows how to make a connection to the Windows CE device and then uses the connection to perform actions. To make a connection, I ported the code from the MSDN documentation for CeRapiInitEx(). The MSDN example includes a function named TryRapiConnect()which attempts to make a connection to the device. The ported code is:

// Code from MSDN

// Copied from C++ examle and converted to C#

private uint TryRapiConnect(uint dwTimeOut)

{

uint hr = E_FAIL;

bool fInitialized = false;

RAPIINIT riCopy = new RAPIINIT();

riCopy.cbsize = Marshal.SizeOf(riCopy);

hr = CeRapiInitEx(ref riCopy);

if (SUCCEEDED(hr))

{

uint dwRapiInit = 0;

fInitialized = true;

dwRapiInit = WaitForSingleObject(

riCopy.heRapiInit,

dwTimeOut);

if (WAIT_OBJECT_0 == dwRapiInit)

{

// heRapiInit signaled:

// set return error code to return value of RAPI Init function

hr = riCopy.hrRapiInit;

}

else if (WAIT_TIMEOUT == dwRapiInit)

{

// timed out: device is probably not connected

// or not responding

hr = ERROR_TIMEOUT;

}

else

{

// WaitForSingleObject failed

hr = (uint)Marshal.GetLastWin32Error();

}

if (fInitialized && FAILED(hr))

{

CeRapiUninit();

}

if (!fInitialized || FAILED(hr))

System.Windows.Forms.MessageBox.Show("Windows CE device does not appear to be connected");

return hr;

}

This function is a attempts to make a connection. It may not be able to because it either times out or an error occurs.

The code for copying the file uses the System.IO.BinaryReader class to read the application on the device and copies it to the device using CeCreateFile() and CeWriteFile().

public bool CeCopyToDevice(string AppName, string FileName)

{

bool ReturnValue = false;

uint RapiResult;

if (!File.Exists(AppName))

return false;

RapiResult = TryRapiConnect(5000);

if (SUCCEEDED(RapiResult))

{

BinaryReader DTFile =

new BinaryReader(File.Open(AppName, FileMode.Open));

System.IntPtr RemoteFile = CeCreateFile(FileName, GENERIC_READ | GENERIC_WRITE, 0, 0, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, 0);

try

{

byte[] Buffer = new byte[1024];

bool Done = false;

int BytesWritten;

int BytesRead;

while (!Done)

{

BytesRead = DTFile.Read(Buffer, 0, 1024);

if (BytesRead == 0)

Done = true;

else

{

CeWriteFile(RemoteFile, Buffer, BytesRead, out BytesWritten, 0);

}

ReturnValue = true;

}

finally

{

CeCloseHandle(RemoteFile);

DTFile.Close();

}

CeRapiUninit();

}

return ReturnValue;

}

You will notice that I chose to call TryRapiConnect()from this function rather than from the CRapi constructor. I can’t say that it is absolutely the right choice, but I did it because I didn’t want to hold the connection open any longer than necessary. ActiveSync connects can come and go, so my thinking here is the minimize the risk of lost connecting by just having it open when it is being used. This choice means that the code will need to open it again to start the application.

CeRunApplication()is used to start the application on the device. This function also calls TryRapiConnect()to make the connection, then uses CeCreateProcess() to start the application and pass in the command line parameters.

public bool CeRunApplication(string AppName, string CommandLine)

{

bool ReturnValue = true;

uint RapiResult;

RapiResult = TryRapiConnect(5000);

if (SUCCEEDED(RapiResult))

{

PROCESS_INFORMATION pi = new PROCESS_INFORMATION();

if(CeCreateProcess(AppName, CommandLine, IntPtr.Zero, IntPtr.Zero, false, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, ref pi))

{

CeCloseHandle(pi.hProcess);

CeCloseHandle(pi.hThread);

}

else

{

System.Windows.Forms.MessageBox.Show("Failed to start application. Errorcode = " + CeGetLastError());

}

CeRapiUninit();

}

return ReturnValue;

}

That’s it, well not completely because there are some supporting functions, data and structures. The rest of the code can be found in the code download at the top of this page.

This app does have some downsides. To use it to run an app on the device, the app must be on your workstation and must be downloaded first. As you can see in the picture of the dialog, I used it to run ipconfig within cmd.exe. Cmd.exe had to be downloaded. The workaround for this is to use RAPIStart, or one of you enterprising developers may want to extend this to select an application that exists on the device instead of the workstation.

NOTE

There seems to be some question about how to run this application. If you download the executable file, you will run it on your Windows XP/Vista/7 computer. To do so, you will need the .NET Framework 2.0 or newer and have ActiveSync running and connected to your device.

If you download the source, you can of course change the .NET Framework version, but you will still run the app on your Windows XP/Vista/7 computer.

Windows CE: Using RAPI to Run Applications (Part 1)

2009-10-29T14:48:48-12:00:00

A few months ago I downloaded the Windows Mobile Developer Power Toys (Download details: Windows Mobile Developer Power Toys) because I had a need for CERDISP, the Windows CE Remote Display tool. At that time, I looked around at the other tools that were installed and played with RAPIStart.exe. RAPIStart.exe is a command line tool that lets you start applications on your device from your workstation using ActiveSync. A handy little tool, so I made a note to try to reproduce it and write a little about RAPI.

I finally got to that point on my list and started writing my version of RAPIStart. Did a little research and started writing a command line tool using C. My research told me that to start an app on the device from a workstation I would need to call CeCreateProcess(). To call CeCreateProcess() we first need to call CeRapiInit() or CeRapiInitEx() to establish a connection to the device.

My research also told me that CeRapiInit() has a tendency to hang if the connection isn’t established, but CeRapiInitEx() is a little friendlier to use because it times out. MSDN even has some sample code for establishing the connection, so I used it. The example function is TryRapiConnect() and since it is available on MSDN, I won’t reproduce it here.

So I created a Visual Studio command line application project and pasted TryRapiConnect() into the file and called it from _tmain(). Being impatient, I tried to compile knowing that I hadn’t done anything to ensure that it compiles like including rapi.h. or set it to link with rapi.h. So it failed. Now the adventure begins. Where do I get rapi.h and rapi.lib. A little searching on my hard disk and I found rapi.h in the Platform Builder files, but no rapi.lib. I thought that it must be available someplace other than the Windows Mobile SDK, but I didn’t find it anyplace else, so I downloaded the SDK and installed it. Then set the includes and lib paths correctly and it builds.

The next step is to create a little test to start a hardcoded application, in this case my registry editor from Windows CE: Simple Little Registry Editor. Here is the code:

int _tmain(int argc, _TCHAR* argv[])

{

HRESULT hr;

PROCESS_INFORMATION pi;

hr = TryRapiConnect(5000);

if( SUCCEEDED(hr) )

{

if (!CeCreateProcess(_T("regedit.exe"), NULL, NULL, NULL, FALSE, 0, NULL, NULL, NULL, &pi))

{

_tprintf( TEXT("Failed to start application (%d)\n"), CeGetLastError());

}

else

{

CeCloseHandle( pi.hProcess);

CeCloseHandle( pi.hThread);

}

CeRapiUninit();

}

return 0;

}

Simple enough and it starts my registry editor when it runs. The next step is to handle the command line arguments for the application name and parameters.

But wait a minute, why am I wasting time developing a command line tool? Did I mention that the source code for a similar tool is available in the Windows Mobile SDK? Why start an app that is already on the device, RAPIStart does that already?

Why write a blog about this? Well it answers a few questions on how to get started, and it shows some C code for using RAPI.

Next step, write a C# GUI app – See Part 2 at Windows CE: Using RAPI to Run Applications (Part 2)

Windows CE Chat Transcript (October 27, 2009)

2009-10-27T13:02:51-12:00:00

For those of you who missed the chat today, here is the raw transcript. By raw, I mean that I copied and pasted the discussion without any edits. This is divided into two parts, the top part is the answers from the Microsoft Experts and the bottom part is the discuss (questions) from the audience.

Answers from Microsoft:

KarelD_MSFT (Expert)[2009-10-27 11:58]: Karel Danihelka - Developer in Partner Response Team.

davbo_msft (Moderator)[2009-10-27 11:59]: Our chat today covers the topic of Windows Embedded CE & Windows Mobile!

1. This chat will last for one hour. During this hour, our Experts will respond to as many questions as they can. Please understand that there may be some questions we cannot respond to due to lack of information or because the information is not yet public.

2. We encourage you to submit questions for our Experts. To do so, type your questions in the send box, select the “ask the Experts” box and click SEND. Questions sent directly to the Guest Chat room will not be answered by the Experts, but we encourage other community members to assist.

3. We ask that you stay on topic for the duration of the chat. This helps the Guests and Experts follow the conversation more easily. We invite you to ask off topic questions after this chat is over, but not during.

4. Please abide by the Chat Code of Conduct.
Chat code of conduct: <http://msdn.microsoft.com/chats/chatroom.aspx?ctl=hlp#Conduct><BR< a>>

davbo_msft (Moderator)[2009-10-27 11:59]: We are pleased to welcome our Experts for today’s chat. I will have them introduce themselves now.

Sing Wee[MS] (Expert)[2009-10-27 12:0]: Hi, I'm Sing Wee, part of the CoreOS/BSP Test Team.

rajran[MS] (Expert)[2009-10-27 12:1]: Hi , I am Rajeev Rangappa, PM in CoreOS team.

RajeevDubey[MS] (Expert)[2009-10-27 12:3]: Hi, I am Rajeev Dubey, Bluetooth Program Manager.

MariNe_MSFT (Expert)[2009-10-27 12:3]: My name is Mariana Nenova - SDET in the Shell team.

MikeThom [MS] (Expert)[2009-10-27 12:3]: Hi I am Mike Thomson, Group Manager from Windows Embedded CE

Sue Loh [MS] (Moderator)[2009-10-27 12:3]: Hi, I'm Sue Loh, a developer on the Windows Mobile tools team (with past experience on the kernel and file system). I hope we can answer some of your questions today!

FBLANQ_MSFT (Expert)[2009-10-27 12:3]: Hi, I'm Francisco Blanquicet, part of the CoreOS/BSP team.

mskim_MS (Expert)[2009-10-27 12:4]:

Q: Regarding Silverlight Runtime in R3 and Expression Blend 2 - Expression Blend 2 appears to be unable to cope with the CacheMode="BitmapCache" tag that's needed for off-screen rendering in the silverlight runtime. Am I doing something wrong?

A: Andrew, CacheMode is from Silverlight3, we added this feature into Cashemere for a better performance but Expression Blend2 doesn't know about this SL3 property.

GLanger_MS (Expert)[2009-10-27 12:5]: Hi, I'm Glen Langer, lead PM for Core and BSPs.

kurtken_msft (Expert)[2009-10-27 12:6]:

Q: Can you point me to any documentation on the "threaded" SMS-message view in tmail.exe; I am having trouble adding my custom context-menu extension to it

A: Are your referring to the Windows Mobile SMS application? This chat is for Windows CE.

MS_Dinglu (Expert)[2009-10-27 12:7]: Hi, I am Dingding Lu, I am in CoreOS/BSP test team

mskim_MS (Expert)[2009-10-27 12:7]:

Q: So if I use Blend 3 will this help or just cause more problems?

A: You can't use Expression 3 with Cashmere, please use Blend2. You will need to add CacheMode only for the device XAML not in Blend2 XAML.

kurtken_msft (Expert)[2009-10-27 12:8]:

Q: Regarding mdd/pdd flash driver. There is some blocks that the MDD allocates for managing the data. Is it save to backup and recover those blocks? Where can we get info about them?

A: Can you give more information on what it is you are trying to do? The MDD's management of blocks is opaque because if it ever changes the only updates will be internal. is there a reason you need to access the internal structures?

Sue Loh [MS] (Moderator)[2009-10-27 12:8]:

Q: Hi! We are developing an app for a new handset running WM6.5 and are having problems when starting up first time. We are built into image and start up at boot since we have set correct reg keys in HKLM\Init. But one test case fails, namely to get reg notif

A: Can you explain a bit better what you mean by your test case fails to get reg notif? Who is supposed to change the registry key, when? Who is waiting on it, when?

kurtken_msft (Expert)[2009-10-27 12:9]:

A: Hi Simon. This chat is for windows CE, and does not cover windows Mobile. The best thing for you to do is contact your WM representative that licenses WM to you to get support.

MikeThom [MS] (Expert)[2009-10-27 12:9]:

Q: Does Wince6.0 R3 include iPOD support?

A: No. There is no integrated support in Windows Embedded CE. There is an automative kit that does supply support for head-units.