Database Info

SQL CE 3.5 - First App

I'm working on developing my first WM 6 App using SQL CE 3.5 . I'm sure there are other apps out there that do what mine does, but I'm just wanting the experience of developing it.
I'm working on a fairly simple app to track gas mileage and such. But, for some reason, whenever I debug it, the app can't seem to find the database file. I get an error saying: "The database file cannot be found. Check the path to the database. [ Data Source = .\GasTrackerDB.sdf ]"
I can browse with file explorer on the device and find the database in the same directory as the deployed application, so I'm not really sure where to go from here..
I'm doing everything through the IDE, so all of the code is generated for me to connect to the database.
Anybody experienced enough to help me troubleshoot this stupid problem?

i have been looking for an app that does the same thing as the one you are working on.
when it is finished please pm me. i wish i knew more programing, if i did i would help you.

Try
Code:
string database = string.Format(@"{0}\GasTrackerDB.sdf", GetApplicationPath());
public static string GetApplicationPath()
{
string path = System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase);
return path;
}

I did figure it out after messing around with it. I think it has to do with the way VS2008 deploys the app on the emulator...
When I hard-code the path to the database file, it works. So, my app will just have to be installed on the local device and not the SD card

Don't hard-code the path! The method GetApplicationPath() returns the application path. This is also important when installing on OS with different language.

heliosdev said:
Don't hard-code the path! The method GetApplicationPath() returns the application path. This is also important when installing on OS with different language.
Click to expand...
Click to collapse
How is that possible when the Connection String was generated by the IDE? Here's what the .xsd says:
Code:
<Connection ConnectionStringObject="Data Source=\program files\gastracker\GasTrackerDB.sdf" IsAppSettingsProperty="false" Modifier="Assembly" Name="GasTrackerDBConnectionString" ParameterPrefix="@" Provider="Microsoft.SqlServerCe.Client.3.5" />

On application start create the connection string "Data Source = " + database (like post #3)
This connection string can then be passed wherever you need to connect to the database.

That's the problem.. the IDE created all the stuff for the connection string and I don't know enough about it to create everything needed manually.

How do you connect to the db? What are you calling for retrieving data from db? How do you insert data to the db? All these actions need an object which somehow knows the connectionstring. And this string can/must be changed.

Hmm.. That doesn't seem to be a valid function name. I'm using .NET CF 3.5 .I'll keep looking.

Well, I wrote my own function to get the execution path, but I still can't figure out how to modify the connection string at runtime.
This crap is ridiculous. I don't understand why it doesn't "just work" when I let the IDE do everything...

Well, I FINALLY made it work.. i ended up going through the xsd file and changing all the code that creates queries. I had to replace every instance of:
Code:
CType(Me._commandCollection(0), Global.System.Data.SqlServerCe.SqlCeCommand).Connection = New Global.System.Data.SqlServerCe.SqlCeConnection("Data Source=.\GasTrackerDB.sdf;")
With:
Code:
CType(Me._commandCollection(0), Global.System.Data.SqlServerCe.SqlCeCommand).Connection = New Global.System.Data.SqlServerCe.SqlCeConnection("Data Source=" & GetAppPath() & "\GasTrackerDB.sdf;")
That had to be done for every one of my queries created through the designer. Thankfully I only had 5!

Great! Keep in mind that changes in generated code can get lost when the ide is recreating the code. Just keep an eye on it when doing changes in this area!

heliosdev said:
Great! Keep in mind that changes in generated code can get lost when the ide is recreating the code. Just keep an eye on it when doing changes in this area!
Click to expand...
Click to collapse
Yeah, I already ran into that one If it gets to be too much of a pain, I'll see if I can create some sort of compile time script to do a find and replace.. But I haven't spent enough time going back and fixing it yet

go to
http://www.connectionstrings.com/
They have everything you need to build your connection string. From my experience, it's okay to let the IDE build everything EXCEPT the connection string....

Programming/Development question

I hope this doesn't get lost in the sea of other questions.
Im working on a little program for my Visual Basic 08 class. Im going a bit further with it and making a windows mobile version of it. (currently using the WinMo 5 SDK) The program works fine in the windows platform, however when i copied the code over to the WinMo version, there was a few issues with the code. Most of it i manage to find the new syntax for and get it working on the WinMo emulator, however there is one problem that persists. TabControl.focus. This function does not seem to work in the WinMo development. Any Code i input that looks for what tab has focus, is ignored, like it doesn't know to look for the focus. Here is what im trying to do.
I have a program, with 2 tabs, and one button. I need that one button to execute two separate code blocks, depending on which tab is active. However i cannot get it to recognize, or do not know the proper function to get it to see which tab has focus, and execute the proper code accordingly.
Now, the simple fix for this would to just make another button, and place one each inside the tab, but i wanted to avoid that for as much as possible, and since it workers fine on the windows end, i know there has to be a way to get it working on the winmo end. By the way, im doing this in VB because im learning VB for a class, and the more coding practice i get the better ill do in class. Im sure there is a better way to do this in C# or whatever else.
Anyone know the workaround for this?
Im currently using Visual Studio 2008 Pro with the WinMo 5.0 SDK.

Your two tab pages are already part of a tabcontrol object. Use that to find the active tab with its property tabControl1.SelectedIndex This will return a zero based index integer for each tab paged attached to it. The object names used here are the default ones created by the IDE
Sorry, I only code in c#, but the VB code will be almost identical.
In the code for the button click event -
if(tabControl1.SelectedIndex == 0)
{
// tabPage1 active
}
else
{
// tabpage2 active
}
c sharp's double equals is the same as VB's single equals, in the sense that it means 'is equal to'.

There is not "active" property in vb (atleast not in vb mobile code) so that doesnt work
Im somewhat fimiular with c++, so i can atleaast understand the code when you put it in C format, but i have a bit of trouble converting C code to vb format. In this case, in normal (non-mobile) the .focus would be enough to make it work...
Here is what i tryed to make work..
Code:
'Changes what the "Roll" button does depending on which program tab is selected.
Select Case True
Case xTabPageCombatRoll.Focus
Call RollCombat()
Case xTabPageRandomRoll.Focus
Call RollRandom()
Case Else
MessageBox.Show("The Tab Control code didnt work")
End Select
both tab pages are part of xTabPageCombatRoll object

I'd suggest asking Development questions in the Dev&Hack section.
(yes, new rules)

Here's the screen shot and the c# application to go with it. Its in VS2005 but VS2008 will open it and convert the solution and project files to 2008 format. Once that happens VS2005 will not be able to open it.
The lines starting // in the code in the previous post above are comments. Same as VB's ;

thanks steph, i have 2005 installed along with 2008 so i just ran 05 . That code does work. But i still cant find anyway to translate that into VB (as .SelectedIndex is not valid in VB code)
ugh.. the more i work with VB the more i like C based code. But im in a VB class so im trying to keep doing stuff in VB so i can pass the class.

SelectedIndex is a property of the TabControl, a .NET framework object It does not matter which language you use to access it. VB, C#, C++, take your pick .
To prove the point here is the same project in VB. I had had to do this on another machine, as I only have C++ and C# installed on this one.
It only had the WM 2003 SDK on it. If your machine has the .NET CF 2.0 the .EXE should work, if you drop it on your device.
Another trick is to use Red Gate's .NET Reflector. If you point it at the original exe generated by the C# project in the previous post above, it decompiles it in C# as
Code:
private void button1_Click(object sender, EventArgs e)
{
switch (this.tabControl1.SelectedIndex)
{
case 0:
this.label1.Text = "Page1 is active";
break;
case 1:
this.label1.Text = "Page2 is active";
break;
}
}
If you decompile it as VB instead you get :
Code:
Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs)
Select Case Me.tabControl1.SelectedIndex
Case 0
Me.label1.Text = "Page1 is active"
Exit Select
Case 1
Me.label1.Text = "Page2 is active"
Exit Select
End Select
End Sub

Ahh..
I got it to work now.. My problem was i wasnt specificly using Case 0 and Case 1, but instead using Case Tabpage1, and Case Tabpage2, which wasn't working.
Thank you VERRRY much.. The program is working like it should now and it makes me verry happy

[Q] Open a Programm twice parallel?

Hi everybody,
is it possible to open a programm twice parallel? I want to open the coreplayer twice, one time for music and another time for audiobook. Is that possible?
thx, mic

It's probably not too hard to write a script for it.
trying talking to either vijay or oldsap.

Depends on the code in the program itself. In the shell code created by Embedded C++ in the InitInstance function there is the following code:
Code:
hWnd = FindWindow(szWindowClass, NULL);
if (hWnd)
{
// set focus to foremost child window
// The "| 0x01" is used to bring any owned windows to the foreground and
// activate them.
SetForegroundWindow((HWND)((ULONG) hWnd | 0x00000001));
return 0;
}
In other words when the application starts, it looks for another active process with the same name as itself. If it finds one, it activates it, then kills itself.

thx for try to help me - that means it is not possible?

The original PPC programming guidelines by Microsoft stipulated that only one copy of a program should be running at any one time. In later versions of Windows CE/PPC a lot more processes are allowed to run simultaneously. They may have changed their tune over this since. Try and launch it twice, then go to Settings->System->Memory and see if there is more than one copy in Running Programs. If there is only one, then I'm afraid the answer is no.
P.S. If you create a Windows Mobile Win32 program in C++ under Visual Studio 2008, it still has the process checking code in it by default.

[Q] web app

Hello,
I dont know if the title fits, so i gonna explain my Problem.
I want to Programm a Game With User Login. Sadly wp7 doesnt Support SQL api, so i cant make the User Management directly over sql.
So i got a Website with a working Login Formular. I want to link the wp7 textboxes with the textboxes of the Website which works with SQL.
Is there a simple way to get this working? Or does anyone have a better idea to get my User Management working?
Greatings win99
Sent from my HD2 using Board Express

Hmm... I can only suggest you to learn how to do http requests (and general programming of course). I hope u'll stop thinking in terms like "linking textboxes"

yeah, "linking" is maybe the wrong word
What exactly do you mean with "http request"?
I can program a bit html an php, which i could include in a "WebBrowser" control. This way i could use php with mysql, but i don't want to make a browser game.
Is there somethink like a "http database"? Cause i don't know yet any database based on http. And is there an API availible to do this requests from a panorama app?
Sorry for this basicly questions, but i'm just a hobby programmer and since now i just programme windows desktop projects, where i could easily use SQL.

Your "very basic question" requires a very long answer (sorry, but I don't have enough time. Also, I'm not an expert in SQL http communication). FYI, all communications between web page (and you can treat your WP7 page as a web page) and SQL server based on HTTP POST requests (but of course not on "linked textboxes"! ). So, try to google with words such as "WP7 SQL HTTP POST" - first five links possible will have all info you need (but you should understand "how everything works" first!)

ok, if i understand it correctly, this sound like instead of using "app<->SQL" i should use "appy<->http<->sql".
i will try to find some good tutorials and reply on success/ no success.

win98 said:
ok, if i understand it correctly, this sound like instead of using "app<->SQL" i should use "appy<->http<->sql".
i will try to find some good tutorials and reply on success/ no success.
Click to expand...
Click to collapse
Well, from the sounds of it, I am going to assume you networking and web API knowledge and maybe decent enough MySQL/SQL/Database knowledge, and possibly somewhat new to WP7 C#.NET (Don't take this personal or a lashing towards you, not the case, I mention it so I can be basic and to the point without assuming you know what references I make or offend you).
If you want an "out-of-the-box" easy solution, let's stop and go download RestSharp (http://restsharp.org). After you get it, visit: https://github.com/restsharp/RestSharp/wiki/Getting-Started, as this will give you a great example of HOWTO use this solution.
You also need to remember about the footprint, a 90MB limit (Max) on 256MB phones. Too big can cause some issues.
Also, another good option is SQLlite, probably one of the most popular, straight forward and well respected (I even use it on some projects). Should you choose to use it, go to http://sviluppomobile.blogspot.com/2010/07/wp7-sqliteclient-preview.html and read his Blog post, VERY informative and a Sample available for you to learn from as well.
If you really wanted to do this yourself, you could create an HTML page and do all your coding in it (e.g. Login Box) and use JavaScript as well, this way you grab the contents from your textbox(s) and send to the embedded web browser you load the HTML page in, hence scripting is available for WP7 but must enable scripting support and highly recommend to use IsolatedStorage and can invoke JS just as easy as:
window.external.notify("(Task)Param)");
So this should hopefully get you to where you want to be but if any of the above statement I made was true, I recommend out-of-the-box solutions for you.
Thanks,
Lance

lseidman said:
If you really wanted to do this yourself, you could create an HTML page and do all your coding in it (e.g. Login Box) and use JavaScript as well, this way you grab the contents from your textbox(s) and send to the embedded web browser you load the HTML page in, hence scripting is available for WP7 but must enable scripting support and highly recommend to use IsolatedStorage and can invoke JS just as easy as:
window.external.notify("(Task)Param)");
Click to expand...
Click to collapse
This is the way i planned to do it. How do you call it? For me it is hard to find a tutorial or book or something like that, cause i don't know which keyword to google
thanks anyway

win98 said:
This is the way i planned to do it. How do you call it? For me it is hard to find a tutorial or book or something like that, cause i don't know which keyword to google
thanks anyway
Click to expand...
Click to collapse
First and foremost, I appreciate your honesty which is why I will basically show you the way...
Well, if you wish to invoke JavaScript via WP7 you can, like below:
1). Open your Mainpage.xaml and find the grid and insert:
<phone:WebBrowser HorizontalAlignment="Left" Name="webBrowser1" VerticalAlignment="Top" Height="xxx" Width="xxx" IsScriptEnabled="True" ScriptNotify="webBrowser_callback" />
2). Make an HTML page, go in the HEADER section and type something like: "<SCRIPT LANGUAGE="JavaScript" src="HelloWorld.js"></SCRIPT>" and add a button that has a function to fire upon clicking + name the section like:
<h1 id='myName'>Hello World!</h1>
<form>
<input id="button" type="button" class="button-standard" style="width:200;height:100" value="Hello World!" onClick="HelloWorld()"/>
* Remove the Quotes from above...
3). Make a file called HelloWorld.js and put in something like:
function HelloWorld() {
window.external.Notify("Name");
}
function sets(val) {
document.getElementById('myName').innerHTML = val;
}
4). In your Mainpage.xaml.cs, find where you want to invoke the script/site and put in:
webBrowser1.Navigate(new Uri("http://lance.compulsivetech.biz/login", UriKind.Relative));
*Change the URI to your address, not my blog's fake login...
5). Since we are loading the site locally in Isolated Storage, go forth and type this in:
private void CreateDirOnStore(string strDir)
{
// Create a directory for local storeage.
IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication();
if (!isoStore.DirectoryExists(strDir))
isoStore.CreateDirectory(strDir);
}
private void SaveFileToIsoStore(string strFileName)
{
// This will save the file to the isolated storage based on the string provided.
IsolatedStorageFile isoStore = IsolatedStorageFile.GetUserStoreForApplication();
//remove the file if exists to allow each run to independently write to
// the Isolated Storage
if (isoStore.FileExists(strFileName) == true)
{
isoStore.DeleteFile(strFileName);
}
StreamResourceInfo sr = Application.GetResourceStream(new Uri(strFileName, UriKind.Relative));
using (BinaryReader br = new BinaryReader(sr.Stream))
{
byte[] data = br.ReadBytes((int)sr.Stream.Length);
//save file to Isolated Storage
using (BinaryWriter bw = new BinaryWriter(isoStore.CreateFile(strFileName)))
{
bw.Write(data);
bw.Close();
}
}
}
6). In your public MainPage() put:
this.Loaded += new RoutedEventHandler(Load_WebPage);
* Always put stuff after your Intialize call
7). We need to make a page load function as below (in xaml.cs):
void Load_WebPage(object sender, RoutedEventArgs e)
{
//Set the start folder of the widget and navigate to the start page
CreateDirOnStore("helloworld");
SaveFileToIsoStore("helloworld/index.html");
SaveFileToIsoStore("helloworld/helloworld.js");
webBrowser1.Base = "helloworld";
webBrowser1.Navigate(new Uri("index.html", UriKind.Relative));
}
8). Now we invoke the function as seen below:
void webBrowser_callback(object sender, NotifyEventArgs e)
{
//Use invokeScript to give to the web env.
webBrowser1.InvokeScript("eval", new string[] { "sets('txtName.Text')"});
}
Hope this helps, this is basically off the top of my head but should be pretty close to being right and Mango Compat.

Creating a WCF services that calls SQL will be the quickest way...about 30 minutes.

Reading a URL

I am trying to make a self steering gear for a boat. The actuator side that moves the tiller uses an ESP8266 and rather than add a compass there along with push buttons and LCD I thought I would try to use an Android phone and send the data to the ESP over wifi.
My starting point is compass_dev from github. This gives me a variable called "azimuth" that is taken directly from the phone/tablet. I do not at this stage need to be concerned with any of the inner working about how azimuth is arrived at and can, for now, just take it as a correct value that I have to work on.
All good so far and working well. The ESP has a PID controller to know how to move the rudder and it accepts from a web page on the ESP, a number that is the angle between a locked heading and the bearing the boat is going on so any number between 180 and -180.
This number is transferred from the main compass application through a singleton into my http handling bit (dohttp). In dohttp I am connecting to my ESP with this:
protected Long doInBackground(URL... urls) {
try {
components = SingletonSession.Instance().getBearing();
URL url = new URL("http://192.168.0.57/msg?msg="+components);
// Log.e("bears", "H11 " + components);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setUseCaches(false);
connection.setDoOutput(true);
connection.setRequestMethod("PUT");
connection.setChunkedStreamingMode(0);
OutputStreamWriter out = new OutputStreamWriter(connection.getOutputStream());
out.flush();
out.close();
connection.disconnect();
}
You can see that the URL is:
http://192.168.0.57/msg?msg="+components
components is normally just the error angle (azimuth - bearing)
If I enter, for example "12" then once this URL is accepted by the ESP the URL will change to:
http://192.168.0.57/msg?msg=12&EX=Execute
So you can see that if the ESP has received correctly I can parse the URL looking for:
12&EX=Execute
If I do not get this then the ESP has missed the value.
The problem I have is that I cannot work out how to read the URL. I do realise that I can add the values to the actual page and parse the data out with a read but it seems a long winded way when just reading the URL would give me what I need if reading the URL is possible.
I am a complete beginner and this is the first java programming I have ever attempted, first use of Android Studio and have really struggled to get this far so please make the answers as simple as possible.Any input is greatly appreciated.
Please excuse me if this is not in the right place, I seem not to have permission to put it where I think it should go and this is the closest I could find that was even slightly relevant.