C# AutoCAD Plugin SQLite - Error Table not found on rare occasions - c#

I am creating a plugin for AutoCAD which uses an external Database(SQLite).
and on rare occasions i am getting the "table not found" error. Its driving me crazy. I have seen plenty of forums for answers could not find a solution.
it is working on most cases only few instances it throwing this error.
How do I solve this issue.
I am using relative path to the DB and it lies within the Debug/ release folder.
What is the best approach to attach a db to a application (in my case its a .dll not exe)
thanks guys for reply...Sorry I didnt get any email notification...
Here is the information you requested.
I have a seperate class-which handles connections.
here is how i I connect to the DB.
public static SQLiteConnection GetConnection()
{
string conn_string = string.Format("Data Source=./sdf_db1.s3db");
SQLiteConnection conn = new SQLiteConnection(conn_string);
if (!System.IO.File.Exists("./sdf_db1.s3db"))
{
Global.variables.mess_out_exception("Missing Database file", "Error");
}
return conn;
}
Since this is a plugin for AutoCAD Civil3D it resides in the Appdata\autodesk folder to load on start-up. Everything about the app is working great except rarely I get the table not found error..looks like may be the relative path cannot resolve quickly when the application is started.
I have difficulty finding the absolute path if I tried to use "Application.ExecutablePath;" and few other things which I find online..all I get is the location of Acad.exe not the location of the plugin.
How do I get the absolute path of the location of the plugin to get the location of the DB(since the DB and .dll lies in the same folder).
How do I use both absolute and relative path in the connection string (so if the relative path fails the code can try to locate the db using the absolute path).
Any other suggestion would be great. Thanks
I Found the cause for the issue,
When I run the application and close the application correctly (Means after completing all the process) it works fine I dont get any error message...
I get the error only when I close the window of the application in between. Looks like the connection opened for the DB is still busy if I try to run the application.

Get the path of the plugin with
var asmpath = Path.GetDirectoryName( Assembly.GetExecutingAssembly().Location );

Why not take an alternate route?
Instead of trying to find your DLL and associated SQLite database, I would recommend that you install them in a specific location. This way you can easily package it with an installer.
You can utilize automatic loading of .NET modules through AutoCAD with registry keys:
http://through-the-interface.typepad.com/through_the_interface/2006/09/automatic_loadi.html
With this, you can simply install your AutoCAD plugins as if they were a normal program, and get AutoCAD to load them for you on launch.

Related

WP8 copy SharedStorge file directly into IsolatedStorage

I am developing a Windows Phone 8 application but am having a lot of issues with file access permission exceptions hindering the approval of my application when ever I try accessing files in the "local" folder (this only happens after the application has been signed by the WP store, not when deployed from Visual Studio). To solve this I have moved all file operations to IsolatedStorage and this seems to have fixed the problems.
I only have one problem left though. My application needs to make use of the file extension system to open external files and this seems to involve the file first being copied to the local folder where after I can then manually copy it into IsolatedStorage. I have no problem in implementing this but it seems that a file access permission exception also occurs once the system tries to copy the external file into the local folder.
The only way I think this can be solved is if I can direct the system to directly copy into IsolatedStorage but I cannot figure how to do this or if it is even possible. It seems as if though the SharedStorageAccessManager can only copy into a StorageFolder instance but I have no idea how to create one that is directed into IsolatedStorage, any ideas?
PS. Do you think that the Microsoft system might be signing my application with some incompetent certificate or something because there is not a hint of trouble when I deploy the application from Visual Studio, it only happens when Microsoft tests it or when I install it from the store using the Beta submission method.
Below is a screenshot of the catched exception being displayed in a messagebox upon trying to open a file from an email:
EDIT:
Just to make it even clearer, I do NOT need assistance in figuring out the normal practice of using a deep link uri to copy an external file into my application directory. I need help in either copying it directly into isolatedstorage or resolving the file access exception.
Listening for a file launch
When your app is launched to handle a particular file type, a deep link URI is used to take the user to your app. Within the URI, the FileTypeAssociation string designates that the source of the URI is a file association and the fileToken parameter contains the file token.
For example, the following code shows a deep link URI from a file association.
/FileTypeAssociation?fileToken=89819279-4fe0-4531-9f57-d633f0949a19
Upon launch, map the incoming deep link URI to an app page that can handle the file
// Get the file token from the URI
// (This is easiest done from a UriMapper that you implement based on UriMapperBase)
// ...
// Get the file name.
string incomingFileName = SharedStorageAccessManager.GetSharedFileName(fileID);
// You will then use the file name you got to copy it into your local folder with
// See: http://msdn.microsoft.com/en-us/library/windowsphone/develop/windows.phone.storage.sharedaccess.sharedstorageaccessmanager.copysharedfileasync(v=vs.105).aspx
SharedStorageAccessManager.CopySharedFileAsync(...)
I've inline the information on how to do this from MSDN http://msdn.microsoft.com/en-us/library/windowsphone/develop/jj206987(v=vs.105).aspx
Read that documentation and it should be clear how to use the APIs as well as how to setup your URI mapper.
Good luck :)
Ok I figured it out. The "install" directory is actually restricted access but for some reason the Visual Studio signing process leaves the app with enough permissions to access this folder. The correct procedure of determining a relative directory is not to use "Directory.GetCurrentDirectory()" but rather to use "ApplicationData.Current.LocalFolder". Hope this helps!

C# and SQLite: "no such table error" when using relative path?

I am having issues connecting to my sqlite database. The file is located in the application's folder. Here is the connection string
string path = "Data Source=MY.db";
I can get it to work if I use the absolute path, but it gives me a "table not found" error if I try to use a relative path. Any ideas?
You are opening up a different -- perhaps a new -- database that does not have said table. (Yes, SQLite will happily create a new database with the default connection settings.)
Make sure the correct database is opened. Remember, relative path is relative to the Current Working Directory, which is likely not that which is expected.
(The working directory is influenced from where, and how, the process is loaded. The working directory for a "Debug" session can be set under Project Settings / Debug / Start Options, for instance.)
Happy coding.
See also:
Make SQLite connection fail if database is missing? (deleted/moved)
Defining a working directory for executing a program (C#) (Shows how to set the current working directory to the directory containing the executing assembly.)
How do I get/set a winforms application's working directory?
Getting path relative to the current working directory?
This happened when you haven't saved the database and its table while using GUI Manager for SQLite .
Two solution;
1) Save your database and its table with CTR+S in GUI Manager
2) Or Simply Just close your GUI manager of SQlite and save all .
Important ! I am using GUI manger for SQLITE (DB Browser for SQLITE) and its all about that.
I've had the same problem for both my windows application (C#) and web application (ASP.net). I usually use SQLite because I found it more easier, especially when I worked with connection strings. But the main obstacle for me was to put a relative path in my code, so I can publish it without worrying about being unable to find the database. I've tried many things(using "|Data Directory|", "~/", "./", ...), and none of them works until I found these solutions. It seems the code is working for me, but wonder if I'm using them right?!
Web Application:
SQLiteConnection sql_con = new SQLiteConnection("Data Source =" + Server.MapPath("~/") + "mydb.db; Version = 3; New = false;);
Windows App:
SQLiteConnection sql_con = new SQLiteConnection("Data Source =" + System.IO.Path.GetDirectoryName(Application.ExecutablePath) + "mydb.db; Version = 3; New = false; Read Only = true");
just replace your .database file into \bin\Debug in project folder, because in your case compiler creates DB file with same name but its totally empty 0bytes

"Parameter is incorrect" when moving file with Windows Service

I've written a Windows Service in C#/VS2008/.NET3.5 that monitors some FTP directories with FileSystemWatchers and moves the files out to another location for processing. I noticed today that it throws errors stating "The parameter is incorrect" soon after the service has started up, but if we wait a few minutes the file gets copied without incident. I saw that the error message is often related to incorrect permissions, but I verified permissions on the directories (target and source) were correct and as I said the file move works just a few minutes later.
Here's a snippet of the code that gets called when the file is finished copying into the FTP directory being monitored:
//found the correct source path
string targetDir = dir.TargetDirectory;
string fileName = Path.GetFileName(e.FullPath);
errorlocation = "move file";
string targetFilePath = Path.Combine(targetDir, fileName);
if (File.Exists(targetFilePath))
{
File.Delete(targetFilePath);
}
File.Move(e.FullPath, Path.Combine(targetDir, fileName));
dir refers to and object with information about the directory the file was being loaded into. e is the FileSystemEventArgs. Targetdir is grabbed from the directory's settings in a custom configuration block in the app.config that tells the service where to copy the new files to.
I didn't include the code here, but I know it's failing on the File.Move (last line above) due to some EventLog entries I made to trace the steps.
Any idea as to why the move fails soon after the service startup, but works fine later?
Basic overview of the process in case it sheds some light: external vendors FTP us a number of files each day. When the file comes in, my code identifies who the file is coming from based off the FTP directory and then loads settings to pass on to SSIS jobs that will parse and save the files. There are maybe a dozen or so directories being monitored right now each of which has its own configuration setting for the SSIS job. Is it possible that the system gets confused as startup and just need some time to populate all the settings? Each source directory does have its own FileSystemWatcher on it.
Thanks for your help.
The first question I'd answer is, what are the values of these when it fails:
e.FullPath
targetDir
fileName
chances are one of those values isn't what you expect
I'm marking this answered because the problem went away. We haven't changed anything in the code, but it now works immediately after restart. The best theory we have is: since I posted this, the client I was working for moved offices and as part of the migration a lot of system and network policies were updated and server setting tweaked for the new environment. It's likely one (or more) of those changes fixed this issue.
Further support for this theory: prior to the move my development VM could not run web browsers. (I'd click to load the browser and it wouldn't work, sometimes it would appear briefly in Task Manager and then disappear.) After the office move, this problem no longer occurs.
So it was likely some network setting somewhere that caused issues. Sorry I can't be more specific.

Writing to appdata folder - permission issue?

I've had a scout around some answers to similar questions but they haven't really helped me much.
I have an app, into which I've embedded some resources. At launch the app checks to see if the resources exist in the appdata folder and if not copies the template files from the embedded resources to the appdata folder before loading them and then using the ones in the appdata folder as the working copies.
I have a helper class which amongst other things returns the appdata and resources subfolder as follows:
class Folders
{
static public String GetUserFolder()
{
return Application.LocalUserAppDataPath;
}
static public String GetResourcesFolder()
{
// If the resources folder does not exist then create it
String userFolder = GetUserFolder();
String resourcesFolder = userFolder + "\\Resources";
if (!Directory.Exists(resourcesFolder))
{
Directory.CreateDirectory(resourcesFolder);
}
return resourcesFolder;
}
...
So my code calls the GetResourcesFolder method which returns the path (creating the folder in the process if it needs to) checks to see if the file exists and if it doesn't tries to write to it using something like:
String filename = Helpers.IO.Folders.GetResourcesFolder() + "\\data.dat";
FileStream outFile = System.IO.File.OpenWrite(filename);
So I've set the scene and this code is working on all the machines I had in the development office. However a couple of off site colleagues have complained it "crashes" on their machines - in each case an XP machine - but otherwise not a lot of useful information coming back from them - working on trying to get something more informative from them. I have XP machines in the office that it has worked on without problems.
After digging out some really old dev machines that were "archived" a while ago, I've managed to have a crash on two xp (sp2) machines also. On both occasions the crash seems to be related to write permissions and running the app using "Run As..." has resolved the problem and it executes correctly. However once the app has been successfully run once the app no longer crashes, even if I delete the files/folders it created from the appdata folder it will still create the successfully on subsequent executions even if I don't elevate permissions.
The problem I have is that I can now no longer repeat the crash on any dev machines available to me and I don't know how to go about putting the machine back into the state where I can.
Anybody got any ideas on what might be causing the problem, or how I may be able to return the machines to a "virgin" state to be able repeat the crash and help me track it down.
One course of action is to create a Virtual Machine of XP. You can save the state of the machine before install for testing. After your install just revert back to the previous state to test again. There are a few Vendors with free Virtual Machines:
http://www.microsoft.com/windows/virtual-pc/
https://www.virtualbox.org/
As too the related problem itself, I don't know a better way than to install VS on a virtual machine for testing purposes.
+1 to Erik's VM solutions for reporducing the issue.
For tracking down permissions issues consider using ProcMon ( http://technet.microsoft.com/en-us/sysinternals/bb896645.aspx ) - will show enverything you ever wanted (and not :) ) about file/regisstry access made by a process. I'd recommend trying it several times first on machine where you program works fine to get filtering setup for your process and get a sense of what should be happening.

Unable to open the Sqllite DB file when lancuhing the application

I used the PostBuildevnt script to launch the application form link
http://blogs.msdn.com/b/astebner/archive/2006/08/12/696833.aspx?wa=wsignin1.0&CommentPosted=true
and launching the app successfully.I am using the sqllite for app.
I added the DB file in Application Folder/DataBase and using the following code to open the Db file.
string ConnectionString = "data source=" + Path.GetFullPath(".") + "\\DataBase\\CATTDB.db";
If i launch the app from the installation wizard,it is not connecting to db file.it is throwing the error like "Unable to open the file".
If i launch from the start menu or desktop icon ,it is working fine..
What is the problem here?
please help me..
It could be that your working directoy is different when started from the installer...
What does Path.GetFullPath(".") return in this case (log and/or display the value)?
There is always the issue of permission/rights - depending on your OS (i.e. Windows 7...) and the user your running the app with (i.a. Administrator?) for security reasons you are not allowed to write in the application directory... if you need someplace with read+write you should use http://msdn.microsoft.com/de-de/library/system.windows.forms.application.userappdatapath.aspx
Just check whether the db is in that path -if not copy it there- and use it there...
Other locations could be ApplicationData/CommonApplicationData/LocalApplicationData from http://msdn.microsoft.com/de-de/library/14tx8hby.aspx and http://msdn.microsoft.com/de-de/library/system.environment.specialfolder.aspx
All the files are copying correctly..
I tried with Application.ExecutablePath instead of Path.GetFullPath(".")
it work's great...

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