How do I cancel recent prints with printDocument.print() in C#? - c#

I have a C# application that prints simple texts correctly with printDocument Class.
The problem is that I want to cancel recent print jobs or Remove them or Purge print queue, before call a new .print() function!
I don't know what I have to do that, it seems PrintDocument doesn't push print jobs onto printer queue! because I dont see any job there.
thanks for help to "clear recent print jobs created with printDocumnet.print()"
Ali.

You should be able to with WMI as long as you have the rights
http://sandit27.wordpress.com/2008/05/12/how-to-cancel-printing-in-c/

I did a lot of work with printers a while back and the way that I achieved most of the functionality I wanted was through PInvoke.
As the answer from #Tsukasa states you "can" use WMI but that's another nightmare that's very difficult to deal with if you plan on actually deploying your solution anywhere other than your own machine.
As I'd mentioned: my suggestion would be to look into PInvoke. Keep in mind though that it has been a number of years/.NET Framework versions since I've worked in the print industry so Microsoft may have released a more elegant, easy-to-use solution that is native to .NET.
Here is a list of Print Spooler functions from the MSDN
Basically what you're going to want to do if you go this route is this:
Find the named handle to the print device in the Registry. This can be done with the registry classes available in the .NET framework. The name of the printer to windows will start with a "#" (or two) followed by some garbled junk and then a GUID. The key where all your printers are installed in the registry is here:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Print\Printers
Call OpenPrinter with the printer name.
Call EnumJobs with the handle retrieved from OpenPrinter.
Call SetJob passing the Job Id retrieved from EnumJobs for the job you want to cancel. Be sure to pass the JOB_CONTROL_DELETE Flag to cancel the job.
Call ClosePrinter, passing the handle retrieved from OpenPrinter. Don't forget this step. Windows/The print spooler gets very cranky if you do.
Again I can't stress enough that there is most-likely a better, more .NET way to do this. I suggest exhausting your options there first.
Good luck.

Related

Using photoshop files from web application

I want to interact with a Photoshop file and create images using its actions and smart objects.
Is there any php or C# API to can do it?
First of all, I would like you to reflect on the legality of such a thing. Would Adobe let you practically just proxy their application to the web? I see they have a lot of licenses so maybe one of them actually grants you permission to do this (however, there could still be caveats so I suggest you read up on that). As that's not the question, I won't talk about this anymore, I just wanted to to mention it as it should be relevant.
Now, for the actual question - if you look at Microsoft Office Interop, Microsoft states that it is unsupported in a server-side environment. Go to this Microsoft page and read Problems using server-side Automation of Office in the More information section.
There are several issues if you decide to run a regular client application server-side, as stated on the mentioned page, but one of the most significant issues is the following:
Interactivity with the desktop:
Office applications assume that they are being run under an interactive desktop. In some circumstances, applications may need to be made visible for certain Automation functions to work correctly. If an unexpected error occurs, or if an unspecified parameter is needed to complete a function, Office is designed to prompt the user with a modal dialog box that asks the user what the user wants to do. A modal dialog box on a non-interactive desktop cannot be dismissed. Therefore, that thread stops responding (hangs) indefinitely. Although certain coding practices can help reduce the likelihood of this issue, these practices cannot prevent the issue entirely. This fact alone makes running Office Applications from a server-side environment risky and unsupported.
While this is written by Microsoft for their product, these are more or less applicable to any regular client application. And even if you still decided to go with this approach, as Neville K already suggested, it would be a very resource-hungry task.
Considering the above, I would maybe ask a different question, along the lines of "What library or server-side app to use for doing whatever you need to do with images".
Based on this link, you can do this things with Photoshop SDK:
"With the Photoshop SDK, you can enable your apps to drive and/or communicate with Photoshop CS6 (version 13.0.0 or later) via a TCP connection. It’s now possible to create an eBook of Photoshop tutorials that allows users to drive actions in Photoshop CS6 from within the eBook"
This sound like hard but some companies seems to make it work. Xee can read PSD too (and has an epic comment about this format in the source code).
But to quote someone over at HN:
PSD was never intended to be a data interchange format: it is the
serialization format of a single program that has more individual
unrelated features that actual people rely on than almost any other
piece of software and has maintained striking amounts of backwards
compatibility and almost unbroken forwards compatibility during its
over two decades of existence. This product's "file format" needs to
be critiqued in this context, along with similar mega-programs like
Office. I am thereby having a difficult time fathoming why anyone
would think that a PSD file is thereby going to be some well-organized
file format that they should easily be able to parse from their own
application is just naively wishful thinking: even other products
from Adobe have limitations while opening these files; to truly
manipulate these files you really need to be highly-compatible with
Photoshop's particular editing model (hence the conceptual
difference between these two classes of file format).
I would recommand to look at Xee for a server side utility.
Good luck.
You can use the scripting interface to kick off "Shell" tasks from any web language if you really want to.
However, I'd seriously worry about this approach - the memory requirements for Photoshop are such that you could only support a couple of users, and you'd need a fairly complex polling mechanism to check for the results of the "shell" task. Photoshop was simply not designed to power web sites in this way.
Consider using graphics libraries instead - I've used ImageMagick with great effect in the past.
Heed the warnings that you really can't process more than 1 or 2 images at a time with photoshop without crashing your server, so just putting it on your webserver is a non-starter. A lighter weight image library is much better for most tasks.
But you could queue up jobs from your web application and then process them on another computer, or limit it to just one at a time.
Adobe has macros and a full action/javascript based scripting environment that you could kick off from commandline or com.
Adobe Scripting Guide
http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/devnet/photoshop/pdfs/photoshop_cs5_scripting_guide.pdf
For older versions of photoshop you can use the macro functionality to Record an action. Then, create a droplet from the action. Call the droplet from the command line with an image file as the sole parameter. The path to the image file probably needs to be an absolute one.

Is it possible to trace file operations with .NET?

Is it possible when a file operation is called somehow - like open or close - that I can handle it before the request proceeds by the operating system and if possible cancel it by .NET? If .NET has no abilities like that, how can I do this?
What your asking to do can be done. Virus Scanners, for example, do it all the time. You can easily monitor file activity with Process Monitor. You can also do it programmically in C# using the FileSystemWatcher Class. But trying to prevent a program from opening up or trying to stop a program from accessing the file can not be done in C#. You will need to use either C or C++. You need to create a File System Filter Driver. It is a complex thing to build but its exactly what you need. To quote MSDN:
A file system filter driver intercepts requests targeted at a file system or another file system filter driver. By intercepting the request before it reaches its intended target, the filter driver can extend or replace functionality provided by the original target of the request. Examples of file system filter drivers include anti-virus filters, backup agents, and encryption products.
You can hook the Windows API if you want to. Check out this way to do that in .NET/C#:
EasyHook Windows API
Sysinternals offers a free tool called Process Monitor, one function of which is to attach to arbitrary Windows processes (including .NET applications) and capture system calls, including file open, close, read, etc.
You can download it at the Process Monitor Download Page.
EDIT
As I re-read your question, I see that you're asking about intercepting and possibly cancelling such operations. I believe the FileSystemWatcher class will be your best bet, although I don't think it can cancel file operations unilaterally - you'd need to build some kind of cooperative mechanism to signal the caller to abort its operation.
I'm pretty sure you've got to get into the kernel on that kind of operation and I'm pretty sure that means you'll need to code in C. Look at File System Drivers.
UPDATE: this SO link may help.
UPDATE: added a google search for Windows File System Drivers
ALSO What is a good resource to get started with Windows file system driver development?

How can i get the Printer details from server using c#

I need to create a C# application that will run in server in that i need to get the printer details like printer status, number of pages printed.The system which is requested for the print that systems username and system name.
If the system connected in the network requested for printing then i need to get the system details in my application
how can i do this?.
sorry for my bad English.
The classes in the .NET 3.0 System.Printing namespace are your starting point. Beware that the amount of functionality available is pretty limited. You can't get an event out of them that tells you that a new print job got started. Something as simple and obvious as counting printed pages is not possible.
This is a core architectural limitation, Windows leaves a lot of the printing management up to a the printer driver. And every printer manufacturer makes their own. Which explains that counting pages isn't supported for example, the driver sends some kind of proprietary control command to the printer to tell it to generate copies of a document rather than Windows spooling the same document repeatedly. That's efficient but not easily observed. These manufacturers also usually have their own printing management software, you probably ought to look at that first.

Patch an application

I need to create a patching routine for my application,
it's really small but I need to update it daily or weekly
how does the xdelta and the others work?
i've read around about those but I didn't understand much of it
the user shouldn't be prompted at all
Ok this post got flagged on meta for the answers given, so I'm going to weigh in on this.
xdelta is a binary difference program that, rather than providing you with a full image, only gives you what has changed and where. An example of a text diff will have + and - signs before lines of text showing you that these have been added or removed in the new version.
There are two ways to update a binary image: replace it using your own program or replace it using some form of package management. For example, Linux Systems use rpm etc to push out updates to packages. In a windows environment your options are limited by what is installed if you're not on a corporate network. If you are, try WSUS and MSI packaging. That'll give you an easier life, or ClickOnce as someone has mentioned.
If you're not however, you will need to bear in mind the following:
You need to be an administrator to update anything in certain folders as others have said. I would strongly encourage you to accept this behaviour.
If the user is an administrator, you can offer to check for updates. Then, you can do one of two things. You can download a whole new version of your application and write it over the image on the hard disk (i.e. the file - remember images are loaded into memory so you can re-write your own program file). You then need to tell the user the update has succeeded and reload the program as the new image will be different.
Or, you can apply a diff if bandwidth is a concern. Probably not in your case but you will need to know from the client program the two versions to diff between so that the update server gives you the correct patch. Otherwise, the diff might not succeed.
I don't think for your purposes xdelta is going to give you much gain anyway. Just replace the entire image.
Edit if the user must not be prompted at all, just reload the app. However, I would strongly encourage informing the user you are talking on their network and ask permission to do so / enable a manual update mode, otherwise people like me will block it.
What kind of application is this ? Perhaps you could use clickonce to deploy your application. Clickonce very easily allows you to push updates to your users.
The short story is, Clickonce creates an installation that allows your users to install the application from a web server or a file share, you enable automatic updates, and whenever you place a new version of the app on the server the app will automatically(or ask the user wether to) update the app. The clickonce framework takes care of the rest - fetching the update , figure out which files have changed and need to be downloaded again and performs the update. You can also check/perform the update programatically.
That said, clickonce leaves you with little control over the actual installation procedure, and you have nowhere close to the freedom of building your own .msi.
I wouldn't go with a patching solution, since it really complicates things when you have a lot of revisions. How will the patching solution handle different versions asking to be updated? What if user A is 10 revisions behind the current revision? Or 100 revisions, etc? It would probably be best to just download the latest exe(s) and dll(s) and replace them.
That said, I think this SO question on silent updates might help you.
There is a solution for efficient patching - it works on all platforms and can run in completely silent mode, without the user noticing anything. On .NET, it provides seamless integration of the update process using a custom UserControl declaratively bound to events from your own UI.
It's called wyUpdate.
While the updating client (wyUpdate) is open source, a paid for wybuild tool is used to build and publish the patches.
Depending on the size of your application, you'd probably have it split up into several dll's, an exe, and other files.
What you could do is have the main program check for updates. If updates are available, the main program would close and the update program would take over - updating old files, creating new ones, and deleting current files as specified by the instructions sent along with a patch file (probably a compressed format such as .zip) downloaded by the updater.
If your application is small (say, a single exe) it would suffice to simply have the updater replace that one exe.
Edit:
Another way to do this would be to (upon compilation of the new exe), compare the new one to the old one, and just send the differences over to the updater. It would then make the appropriate adjustments.
You can make your function reside in a separate DLL. So you can just replace the DLL instead of patching the whole program. (Assuming Windows as the target platform for a C# program.)

Windows clipboard CRLF/LF passing wrong for one user

We have a pair of applications. One is written in C# and uses something like:
string s = "alpha\r\nbeta\r\ngamma\r\ndelta";
// Actually there's wrapper code here to make sure this works.
System.Windows.Forms.Clipboard.SetDataObject(s, true);
To put a list of items onto the clipboard. Another application (in WinBatch) then picks up the list using a ClipGet() function. (We use the clipboard functions to give people the option of editing the list in notepad or something, without having to actually cut-and-paste every time.)
In this particular environment, we have many users on one system via Citrix. Many using these pairs of programs.
Just one user is having the problem where the line delimiters in the text are getting switched from CRLF to LF somewhere between the SetDataObject() and the CLipGet(). I could explain this in a mixed Unix/Windows environment, but there is no Unix here. No unix-y utilities anywhere near this system either. Other users on the same server, no problems at all. It's like something in Windows/Citrix is being "helpful" when we really don't want it, but just for this one guy.
Ideas?
Have you tried clearing their profile on Citrix? That seems to be the solution to many many user specific Citrix problems.
Does Environment.NewLine behave differently on Citrix environments? If so, it may give you a good option that works for all users instead of \r\n.

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