In my ASP.net application, i have to open a EXE on click of button. When the EXE is open, User should not be allowed to perform any action on the web form, i.e. the exe should behave like a modal popup. I am using the current code to open and return value from EXE.
Dim p As Process
p = Process.Start("D:\VS2010Projects\SignatureCaptureWindows\bin\Debug\SignatureCaptureWindows.exe")
p.WaitForExit()
If (Not p.ExitCode.Equals(0)) Then
Response.Write("Image Successfully saved in Database with ID = " + p.ExitCode.ToString())
DisplaySavedImage(p.ExitCode)
End If
The Exe is opening fine and returning the correct value. However, the user is able to perform action on the web form when the exe is open...
What will be the best way to handle such a scenario ??
Its impossible to do the way you won it. From the moment the user send a submit, or try to open the page, and on code behind you run this exe, then user is wait for the results - in this time you can not make the user to not do anything else - you can not lock the browser, user can close it, reload it, open again the same page, etc.
What you can do is to lock this process using Mutex and not allow to run again if all ready run it.
Mutex on msdn with example : http://msdn.microsoft.com/en-us/library/system.threading.mutex.aspx
Related
The run button in PopSQL greyed out a while ago after I restarted my laptop. No matter how I tried I couldn't click on it. I re-checked, double-checked my queries but it still didn't work.
Please help.
First of all, check the following -
Your query - Check for semantic errors.
Your database connection - There may be some fault in the connection itself. Try connecting again with the database. Check if just above the tab where the connection is specified if you can see your database name like this -
If you have just installed MySQL in your laptop (or anyways, now you don't have any other option) -
Open run from Start Menu or press windows key + R.
Search for 'services.msc'.
In the search window, search for MySQL80. Double click on it to open.
You will notice that the service is either disabled (in startup type) or stopped in the service status.
Select Automatic or Automatic (Delayed start) in the select box of Startup type and click on apply. So that whenever your machine starts the MySQL service will start automatically in the background.
After that click on the Start button to start the MySQL service on your machine. It will take a few seconds to start.
Then click on apply and hit Ok. Then close the services window also.
Now try opening PopSQL you'll see that database connection has been corrected.
ENJOY!!!
I Have created a application, in SAP ABAP and also I have generated a request number for that application, no I have forgot which is my request number since there are many requests in development server.
So, can someone help me how I can find out my request number, from my application.
Either you start transaction SE10, if necessary enter your user name (should be there by default) and hit Enter. You'll get a complete list if your transports, you just have to find the one, you need.
Or you start the transaction where you developed your application (you did not specify, if it is a program than SE38 or SE80, if it is a function module than SE37, SE24 for classes, etc (however in SE80 you can see everything)) enter the program name and go to menu: Goto / Object directory entry, a popup comes up, now click the button 'Lock overview'. Another popup comes up and tells you, which transport contains your object.
Steps to Identify all the request numbers of an object/application.
Open 'SE38'.
Provide your object/application name.
Click on 'Display Button'.
In the Menu bar click on 'Utilities'.
Click on 'Versions' --> 'Version Management'.
Now we can find all the request numbers of that object/application.
I try to call an .exe file from a webapplication.
But I want the file called by the user that is impersonalisated by windoes authentication from the website.
Process process = new Process();
try
{
process.StartInfo.UseShellExecute = false;
process.StartInfo.FileName = ConfigData.PVDToBudgetDBexePath;
process.StartInfo.CreateNoWindow = false;
process.Start();
log.Info("Process started by " + WindowsIdentity.GetCurrent().Name + " with ID: " + process.Id);
process.WaitForExit();
log.Info("After WaitForExit Process ID: " + process.Id);
}
catch (Exception ex)
{
log.Error("Error executing file with message " + ex.Message);
}
Both info log texts are logged correctly. There is no error occuring.
But the called Program does not do anything. No logging, no writing in Database.
The user has executable rights on the file.
When I call the same Code from Development Server it works fine.
I use .Net 4.5 and IIS 7
I found posts concerning this topic only for very old versions of .Net and IIS and that could not help me.
What am i doing wrong?
Or how can I find out whats going wrong?
many thanks,
EDIT:
To better make clear what I intend:
I have this (self made) exe file that imports Data from Excel Sheets into a Database. That needs some time. While doing this it logs its Progress whith log4net also into the database.
I want an UI (web application) were the user can trigger the import.
on this UI there is also an ajax progressbar that shows the progress of the import takten from the log table in the database.
I want maximum one instance of this import process to run in the same time. So I have a function that checks wheter the process is still running.
If so it does not allow to start another process. If not you can start it again.
private bool IsRunning(string name)
{
Process[] processlist = Process.GetProcesses();
if (Process.GetProcessesByName(name).Length > 0 )
{
return true;
}
else
{
return false;
}
}
I solved the problem now by starting the exe file via TimeScheduler.
path = filepath to the exe file
arguments = arguments to start the exe file with
using Microsoft.Win32.TaskScheduler;
using (TaskService taskService = new TaskService())
{
var taskDefinition = taskService.NewTask();
taskDefinition.RegistrationInfo.Author = WindowsIdentity.GetCurrent().Name;
taskDefinition.RegistrationInfo.Description = "Runs exe file";
var action = new ExecAction(path, arguments);
taskDefinition.Actions.Add(action);
taskService.RootFolder.RegisterTaskDefinition("NameOfTask", taskDefinition);
//get task:
var task = taskService.RootFolder.GetTasks().Where(a => a.Name == "NameOfTask").FirstOrDefault();
try
{
task.Run();
}
catch (Exception ex)
{
log.Error("Error starting task in TaskScheduler with message: " + ex.Message);
}
}
If you mean by development server the web server that is launched by Visual Studio, than this gives you a false test case since that server is launched by Visual Studio and uses your Windows account to run, while a standard configured IIS does not run under a "user" account but a very limited system account (luckily !!). Even if the user is logged in with a domain account in your website, the IIS process will not run under this account (that wouldn't make sense anyway). That is the reason why this code will not run in IIS and will run in your development server. Even if you get the exe to launch, it will run using the system account of IIS since you didn't supply any account, which is a limited account which will again run the exe different than you expected.
You will have to use impersonation, if you really want to go this way, but you will have to launch that process "impersonating" the user that is logged in in the website, asuuming that user account used to login even makes sense at that point. E.g. if it is a domain account, this might work, but if you use some other kind of authentication, like forms authentication, this has no meaning on OS level and thus you cannot use those credentials for impersonation in IIS.
In my experience, and I have done this a few times, impersonation in IIS is always a bad thing and is always creating issues, the same goes for launching command line process by the way.Luckily there is always a better/alternative solution when you think about it. Also the wait for a process to end in your code is not really a good practice. What if the process blocks? It will block website.
Luckily there is always a better/alternative solution when you think about it. A better/possible solution here is to use message queuing for example, where you just push a message to execute the task, and on the other end an application which processes the messages, which might use this command line tool then. That application can run under any user account you want, without you having to let IIS run under a different account. Later on you must of course come back to find the result of the operation, but that can be done using a callback in the background of your website. though this solution is a little bigger than what you are trying to do, it will have a better result on almost every field (responsiveness of your site, maintainability, scalability,..) the only thing where it is worse is the lines of code that you will need, but that is seldomly a valid factor to take into account
If you write the appplication for excel processing yourself, you can use a table in the DB as some kind of queue instead of using a message bus. Your web application then just needs to add rows with all necesarry info for the process in that table, the status and progress being one of them. Extend your processing application to monitor this table continuously and as soon as it detects a new record, it can then start to do the necessary task and update the db accordingly progress and status and end result). This avoids the messaging sub-system, will work equally good and will avoid you to have to launch a process with impersonation, which was the evil thing to start with.
You can modify the excel process to a windows service so that it runs continuously and starts with the system, but, if you don't want to, there are also tools to run any command line application as a windows service).
This technique would be much easier than the impersonation and allows your website to run in it's protected environment
I have a scheduled task set up to run Scan.aspx every 3 minutes in IE7. Scan.aspx reads data from 10 files in sequence. These files are constantly being updated. The values from the file are inserted into a database.
Sporadically, the value being read is truncated or distorted. For example, if the value in the file was "Hello World", random entries such as "Hello W", "Hel", etc. will be in the database. The timestamps on these entries appear completely random. Sometimes at 1:00 am, sometimes at 3:30 am. And some nights, this doesn't occur at all.
I'm unable to reproduce this issue when I debug the code. So I know under "normal" circumstances, the code executes correctly.
UPDATE:
Here is the aspx codebehind (in Page_Load) to read a text file (this is called for each of the 10 text files):
Dim filename As String = location
If File.Exists(filename) Then
Using MyParser As New FileIO.TextFieldParser(filename)
MyParser.TextFieldType = FileIO.FieldType.Delimited
MyParser.SetDelimiters("~")
Dim currentrow As String()
Dim valueA, valueB As String
While Not MyParser.EndOfData
Try
currentrow = MyParser.ReadFields()
valueA= currentrow(0).ToUpper
valueB = currentrow(1).ToUpper
//insert values as record into DB if does not exist already
Catch ex As Exception
End Try
End While
End Using
End If
Any ideas why this might cause issues when running multiple times throughout the day (via scheduled task)?
First implement a Logger such as Log4Net in your ASP.NET solution and Log method entry and exit points in your Scan.aspx as well as your method for updating the DB. There is a chance this may provide some hint of what is going on. You should also check the System Event Log to see if any other event is associated with your failed DB entries.
ASP.NET is not the best thing for this scenario especially when paired with a Windows scheduled task; this is not a robust design. A more robust system would run on a timer inside a Windows-Service-Application. Your code for reading the files and updating to the DB could be ported across. If you have access to the server and can install a Windows Service, make sure you also add Logging to the Windows Service too!
Make sure you read the How to Debug below
Windows Service Applications intro on MSDN: has further links to:
How to: Create Windows Services
How to: Install and Uninstall Services
How to: Start Services
How to: Debug Windows Service Applications]
Walkthrough: Creating a Windows Service
Application in the Component Designer
How to: Add Installers to Your Service Application
Regarding your follow up comment about the apparent random entries that sometimes occur at 1am and 3.30am: you should:
Investigate the IIS Log for the site when these occur and find out what hit(visited) the page at that time.
Check if there is an indexing service on the server which is visiting your aspx page.
Check if Anti-Virus software is installed and ascertain if this is visiting your aspx page or impacting the Asp.Net cache; this can cause compilation issues such as file-locks on the aspnet page in the aspnet cache; (a scenario for aspnet websites as opposed to aspnet web applications) which could give weird behavior.
Find out if the truncated entries coincide with the time that the files are updated: cross reference your db entries timestamp or logger timestamp with the time the files are updated.
Update your logger to log the entire contents of the file being read to verify you've not got a 'junk-in > junk-out' scenario. Be careful with diskspace on the server by running this for one night.
Find out when the App-Pool that your web app runs under is recycled and cross reference this with the time of your truncated entries; you can do this with web.config only via ASP.NET Health Monitoring.
Your code is written with a 'try catch' that will bury errors. If you are not going to do something useful with your caught error then do not catch it. Handle your edge cases in code, not a try catch.
See this try-catch question on this site.
I am working on web application , in my project there is some type of testing and task assignment to employees.
Now when an employee complete a task and assigned to a user the user automatically get the message on his page ( there is 3 user accessing application , one is admin , second is tester and third is verifier ...both of them works on different pages , now when admin assign a task the tester automatically get a notification " new message " ( for this i am using master page)..on whatever page the tester is on working... now if the tester is completes it 's task and assign to verifier , verifier must get notification "new message" ... and so on..)
for this a have put a button on master page ..and also i have make a windows service that runs on every minute , now my problem is how i sent the message from windows service to my master page button ( that i change text of button).
Is this idea working ?
Why do you need to window service to run in background? Is there any specific reason to have the windows service for these requirements?
As per your detailed description what I understood is that when the employee completes a task and assigned to a user the user automatically get the message on his page. So when the employee is working and completed means they will click on some button that their work is completed. Then while clicking on the button, you just write the code for sending the mail to the tester. like the same way, when the tester is completed their work and click on the testing completes, send a mail to the reviewer and so on..Then where is the need to have a window service for this to send the mails?
All the requirements can be achieved through the simple send mail code.
Let us know if you need any more help or if you don't understand the exact scenario or if anything is missing in the requirements.
Hope it will be helpful to you.
I don't think it is possible to send from a windows service informations to asp.page. You can create a button that can query a webservice about new tasks (but you are counting on the user to press it).
Another more "friendly" way is to have a timer in javascript that uses ajax requests to get new tasks.