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I am new to mobile app programming, how much memory is generally expected to be available in contemporary devices using Window CE or equivalent? I have a stand-alone Windows application framework that can run Windows applications down to about 2 megabyte footprint. If it can fit into a telephone device, a whole new market may open up for me.
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Most Windows Mobile devices available today ship with 128-192MB of RAM. Not all of it is available for applications, since the RAM is also used for loading the OS and storage of files. The memory for running programs would be 30-60MB. In my old phone (64MB of RAM) I have 15MB available. In Windows CE you can fine tune this setting (favor application RAM over storage RAM and vice versa), but in Windows Mobile the ratio is handled automatically by the OS.
I would say that 2MB is a bit high for a mobile application, but still not a forbidding value. You need of course to do some testing in an actual device before deciding.
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#include <windows.h>
#include <wincrypt.h>
#include <iostream>
using namespace std;
static HCRYPTPROV hProv = NULL;
static HCRYPTPROV hNewProv = NULL;
static HCRYPTKEY hKey = ERROR_INVALID_HANDLE;
DWORD nOutBufSize = 4096;
char lpOutBuf[4096] = "";
DWORD BytesReturned = 0;
int wmain()
{
//if CryptAcquireContext is successful then go inside otherwise not
if(CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT))
{
if(!CryptGenKey(hProv, AT_KEYEXCHANGE, 0, &hKey))
{
//WriteDebugMessage(L"GMDSD: FILTER_DeviceIoControl called CryptGenKey failed", eError);
}
}
else
{
//WriteDebugMessage(L"GMDSD: FILTER_DeviceIoControl called CryptAcquireContext failed", eError);
}
unsigned char buff[4096] = "DATA";
DWORD len = 7;
CryptEncrypt(hKey, 0, TRUE, 0, buff, &len, nOutBufSize);
CryptDecrypt(hKey, 0, TRUE, 0, buff, &len);
cout<<buff; //this buff should display "DATA"
return 0;
}
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Hi,
I am developing a small app under Windows Mobile 6 with VB.NET. I realized that I am not able to perform multiple selections for some controls including Listview and Listbox. Therefore I saw that extended styles are used for some purposes. Therefore It is requried to write a partial class in some controls to enable such tasks on the controls. It is a blocking issue for a populated listview in design time.
Would you please give me a sample to show, how you can select mutiple items for a listview. I would really appreciate it.
Thanks.
What a curious mind needs to discover knowledge is noting else than a pin-hole.
modified on Tuesday, December 16, 2008 6:16 AM
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Did you set MultiSelect to true?
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In mobile development WM 6.0 there is no multiselect property associated to listview in design time but strangely selectedindices property. I am not able to perform multiple selection in listview in runtime. I think it requires an extended style pinvoke methods (API CALLS) that is what I am looking for.
Thanks.
What a curious mind needs to discover knowledge is noting else than a pin-hole.
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My apologies. I was thinking about the full desktop framework. as you have pointed out the compact framwork does not have this property. I found some code[^]some one else posted in which he made a few Win32 calls to make the listView allow multiple selections.
If you don't have a UUE decoder use then Winzip.
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Hi all,
I have a little (and I hope simple) problem with using of OpenFileDialog in a .Net C.F. aplication:
When I open OpenFileDialog1 to choose the file to open/read, it remains active/visible for all time that the choosen file is reading.
And as to reading the file sometime need also 4 minutes, I would like that OpenFileDialog1 remain visible only for time needed to choose the file, and immediately after it disappears to show again the main form.
But I don't know to do it (OpenFileDialog1 doesn't accepts .close).
Here a piece of my code:
Private Sub MenuItem2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles MenuItem2.Click
openFileDialog1.InitialDirectory = "\My Documents"
openFileDialog1.Filter = "wpt files (*.wpt)|*.wpt|txt files (*.txt)|*.txt"
openFileDialog1.FilterIndex = 1
If openFileDialog1.ShowDialog() = DialogResult.OK Then
myStream = openFileDialog1.FileName
NomeFile = myStream
Me.Text = "Waypoints Manager - " + myStream
Using sr As StreamReader = New StreamReader(myStream)
CountLines = 0
Do
line = sr.ReadLine()
If line = Nothing Then Exit Do
CountLines = CountLines + 1
Loop Until line Is Nothing
sr.Close()
End Using
Can someone help me please?
Thanks
Ignazio
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Without looking at your code I can tell what's going on since it is such a frequently occurring question.
The problem you are encountering is intrinsic to applications with single threads. The OpenFileDialog isn't still active. It is closed. However, your application hasn't redrawn it self so the last image that was on the screen remains visible until it does.
Right now you are reading the file on your primary thread, and while that primary thread is busy reading the file it does not have the opportunity to redraw the main window. When the read operation completes then the application can use that thread to redraw the main interface.
To prevent that behaviour you will need to read your file on a secondary thread so that the primary thread is still free to redraw the main interface. This concept can be applied to both desktop and mobile applications written with managed and native code. Please read the following for a more complete explanation of the problem you are encountering and the solution.
Give Your .NET-based Application a Fast and Responsive UI with Multiple Threads
modified on Sunday, December 14, 2008 4:51 PM
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Thank you very much Joel!
Your posts are precise and reliable as usual.
I will follow your advice.
But While I was trying to resolve the problem, I made this simply modify to the code:
I placed the OpenFileDialog1 code and the file reading code in 2 different Sub, and in the first line of reading Sub I added ME.Refresh() statement.
It seems that this modify works and the OpenFileDialog1 disappears before the file is read (as I desired).
Ignazio
modified on Monday, December 15, 2008 4:35 PM
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I'm just starting WM development and I'm trying to use VS 2008 Pro 90 day trial, since it is closest to the C I've programed embedded applications (for specialized devices like digital satellite receivers, flight data recorders, transmission controllers, and a few other things).
I'm looking for some samples or documentation on getting started.
I've looked at the samples with the WM5 SDK,
PocketPC->CPP->ATL
PocketPC->CPP->Mfc
PocketPC->CPP->Win32
I'm confused what the difference is in these example categories (I built and ran these, or the ones that would build).
I also tried to find samples here, and was looking in the Mobile Development (http://www.codeproject.com/KB/mobile/[^]) but I'm not sure which would be for C++ development for a WM5 or WM6.x device.
Can anyone point me in the right direction, or is there an article I've missed that explains these differences?
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Development Technologies
Win32
The Win32 code examples are based off of the Windows API and nothing more. Projects of this type of the potential to be the smallest of the different project types with the lowest level access at a cost; you'll have to make more function calls to perform certain tasks (such as creating a window) than you would in the other project types.
MFC
MFC is a step up from Win32. You still have access to all of the low level Win32 APIs but you don't have to make the low level calls for some rather routine tasks such as creating a window or a button. Instead the MFC framework offers a set of classes that encapsulates this functionality. You mentioned having a C background. MFC is based off of C++ and is object oriented. If you have not worked with Object Oriented Programming before then your 90 days may be better spent in targeting Win32 projects.
ATL
Like MFC, ATL is a framework library that abstracts away several low level tasks. I've never used it myself so I can't speak on it beyond that.
.Net and C#
If you have familiarity with object oriented concepts then your 90 days will be better spent targeting .Net as your project type. Like MFC the .Net framework abstracts away a lot of routine task. It adds a layer of separation between you and the lower level APIs but you'll find that it meets most of your needs. You didn't ask about this technology but I am encouraging you to look into it. Microsoft is releasing a series of webcast called "24 hours of Windows Mobile" that covers different aspects of mobile development using .Net. I've indexed some of the web cast that they have done in this series at th following URL. At the very least look at the introduction webcast.
Compatibility
For the most part anything you see that targets Windows Mobile 5 will work on Windows Mobile 6. In many (but not all) cases code that is said to target Windows Mobile 6 will work on Windows Mobile 5. The main factor that bifurcates the platform is whether a device is running Windows Mobile Standard or Windows Mobile Professional. A phone running Windows Mobile standard does not have a touch screen. A phone running Windows Mobile Professional has a touch screen (there are other differences but those are the primary differences).
Some one had once asked about Windows Mobile development in the MSDN forums. I saved the response that I gave the person thinking that others may find it helpful. You can read it here.
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Hello
I am developing a application for window mobile 5.0. and i want to print some reports from window mobile to my network printer. how i print the document using window mobile. please suggest.
Thanx
Khatri Mitesh
~Khatri Mitesh
khatrimitesh@hotmail.com
Bikaner (Rajasthan)
INDIA
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Windows Mobile doesn't have printer support. You'll either need to create your own abstraction layer to talk to your printer or purchase a third party product.
PrintBoy Wireless is the only such product of which I know. You'll want to do research to see if there are others.
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Hi,
Why CPU allocates allocate the memory region, rounded to a 64 KB boundary?
Regards,
Chandan
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It's not the CPU allocating memory. It's the operating system and the run time. You've not made mention of what mobile technology you are using (Symbian, Windows Mobile, ...?) so I can't give you the specifics. But memory is always allocated from the OS in blocks. The size of those blocks will vary with the OS and it sounds like the OS that you are using allocates memory in 64kb blocks. If you allocate memory on a desktop it will also be allocated in blocks of a certain size.
The size of the block may also vary depending on the runtime you are using. For example, code written against one runtime may cause that run time to acquire a block of memory from the OS and then divide that block into smaller blocks to give to your program as needed.
You'll want to do some reading on memory allocation algorithms to get a complete description of what is occurring.
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Hi,
I am writing an application on windows mobile 6. I would like to capture still images using the mobile phone's built in camera and use these images in my application. The capturing process need to be done in the background while the other phone applications are running normally. Does anyone have an idea how this could be done?
Cell phone brand: I-mate ultimate 9502
Thanks,
Regards,
Sherin
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You need to use DirectShow. This blog entry[^] is a good starting point.
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Hi,
I have created a J2ME application, when I try to install it on my Nokia N73, Nokia 6233, it gives an error saying that "this application is not compatible with this phone", but the same application is working fine in the simulator.
can anyone let me know how can we solve this problem.
Thanks in advance
Regards
Parasmani
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I see many J2ME related questions lately, but I think that this isn't the most appropriate forum to ask this kind of questions. All major phone manufacturers have j2me related forums with the ones from Nokia and Sony Ericsson being more popular. Another forum frequently visited by experts is j2meforums[^].
To answer your question, you've probably built your application for a MIDP or CDLC version not supported by the phone. Or, less likely, you've used an API not available in the device.
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I'm trying to catch the mouse down and up event and add them to a button control.
I'm planing to use IMessageFilter to add the missing events.
Now to my problem, It seems like application.addfilter don't exist's in cf...
Do anyone have a clue on how to catch mouse events in cf??
Or perhaps i'm looking in the wrong direction? Is there a better way to do this??
Thanks
Ola
modified on Tuesday, December 9, 2008 12:39 AM
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The Mouse Down and Up events are already available for the button control. Why don't you extend it to add the desired functionality?
If you are actually trying to create a global mouse event hook, this is not possible in Windows Mobile.
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According to a lot of places mouse down and other event's are not supported ny .net compact framework.
I have looked for the mouse down event in my visual studio 2008, and it's simple not there.
I have found several links to msdn forums stating that this is one of the things not implemented in the comapct framework.
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You are right - the mouse down and up events aren't available for buttons. I remember seeing them in CF applications and I erroneously assumed they were available.
I've checked and they are available for Panel control. Perhaps you could override this to have button functionality. Or may be there is a simple control that supports these events and can serve as basis.
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