C# PrintQueue AddJob printingHandle throws null exception - c#

I'm trying to print a file with C#. I have made some headway in listing off all the printers and then wrote some simple logic to select the correct printer:
var server = new PrintServer();
var queues = server.GetPrintQueues(new[] { EnumeratedPrintQueueTypes.Local, EnumeratedPrintQueueTypes.Connections }).ToList();
int count = 0;
foreach (var q in queues)
{
Console.WriteLine(count++ + " " + q.Name);
}
int iSelection = 0;
while (true)
{
Console.Write("Select printer: ");
string selection = Console.ReadLine();
if (int.TryParse(selection, out iSelection) && iSelection >= 0 && iSelection < queues.Count())
{
break;
}
else
{
Console.WriteLine("Bad selection, try again.");
}
}
The next step, as for the posts I've seen on this site, is that you need to select the specific queue, and then add a job, grab the job stream, and write to the stream (at least that's how I want to try to do it, unless it's wrong?)
var queue = queues[iSelection];
var job = queue.AddJob(#".\Test.txt");
var stream = job.JobStream;
var file = File.ReadBytes(#".\Test.txt");
stream.Write(file, 0, file.Length);
When I do this, the program crashes at the line with AddJob. Specifically,
System.ArgumentNullException: 'Value cannot be null, Parameter name: printingHandler'
Now, I think I understand what the issue is. I had been playing with System.Drawing.Printing.PrintDocument yesterday, but I am trying to find a solution that allows me to print files, rather than manually draw them out and them print them. Ultimately, the goal in the future is to be able to print out text and PDF files (I was hoping that this solution would allow me to open a PDF file and dump the bytes into this stream, but I don't know if that's the correct way to this?)
Anyway, the exception I got I think is something similar to PrintDocument's PrintPageEventHandler, I need to add a callback to the PrintQueue somehow that tells it the font, color, font size, etc. Problem is that I see nothing for PrintQueue that allows me to add a handle for it to fix this issue.
What can I do to fix this exception?

I was having this issue as well. Eventually I found out that we need to call into Refresh() of the selected PrintQueue instance and before calling AddJob().

Related

How can I get an incoming email's message in C#?

The code I am using at the moment is
try
{
//using MailKit.Net.Pop3;
string pathLog = System.Environment.GetFolderPath(System.Environment.SpecialFolder.LocalApplicationData);
string fileNameLog = Path.Combine(pathLog, "pop3.txt");
using (var client = new Pop3Client(new ProtocolLogger(fileNameLog)))
//using (var client = new Pop3Client(new ProtocolLogger("pop3.log")))
{
strProgress = strProgress + "c";
client.Connect("outlook.office365.com", 995, SecureSocketOptions.SslOnConnect); //POP3 port is 995
strProgress = strProgress + "d";
client.Authenticate("xxx", "yyy");
strProgress = strProgress + "e";
for (int i = 0; i < client.Count; i++)
{
strProgress = strProgress + "f";
var message = client.GetMessage(i);
strProgress = strProgress + "g";
//Write the message to a file
message.WriteTo(string.Format("{0}.msg", i)); //<<<<<<<<<error here
numCountEmailsDownloaded = numCountEmailsDownloaded + 1;
}
client.Disconnect(true);
}
}
catch (Exception ex)
{
Toast.MakeText(this, ex.Message + "\n\nStopped after " + strProgress, ToastLength.Long).Show();
}
I get an error message which says 'Access to the path "/0.msg" is denied. Stopped after abcdefg (I use strProgress to mark where the error is).
I've tried getting the email body as a string but the error message says 'Do not use string to serialize ...use WriteTo instead', except that it doesn't tell me what to do with it even if it worked.
The idea of receiving emails and then wanting to know what they say must be a common one, but many other questions and answers on the web seem to think it isn't worth actually spelling out.
How can I extract the email body text from the above? Thank you.
You are trying to write the message to a file in the current working directory. This will most likely be the application's path.
Applications are generally installed under the Program Files folder. Regular users do not have permission to write to that folder.
You will need to use a different path to store your files. For example, somewhere under the LocalApplicationData folder which you're using for your log files.
Where should I store my data?
I've tried getting the email body as a string
If that's what you really want, maybe replace the line with this:
string messageBody = message.GetTextBody(MimeKit.Text.TextFormat.Plain);
as per the docs for the MimeMessage type. See more options for the TextFormat here:
http://www.mimekit.net/docs/html/T_MimeKit_Text_TextFormat.htm
This may also work:
string messageBody = message.TextBody;
In both cases this is looking for the Text option within a MIME message. It's somewhat common these days to find messages where the text format doesn't exist, and the message only includes an HTML content body. In that situation you need to know how to check both the text and fallback to HTML (or vice versa).
Otherwise, answers and comments suggesting file permissions sound right on the mark.

Trouble with transfer function in WIA C#

I have a problem with the below code. I want to scan a document by clicking a button in a WinForms C# application.
I use WIA, Visual studio and the scanner Fujitsu N7100A working with Windows 8. I am following a tutorial online for using WIA.
But the program doesn't run as expected. It seems to break down at the Transfer method.
// Create a DeviceManager instance
var deviceManager = new DeviceManager();
// Create an empty variable to store the scanner instance
DeviceInfo firstScannerAvailable = null;
// Loop through the list of devices to choose the first available
AddLogs(deviceManager.DeviceInfos.Count.ToString(), filename);
foreach (DeviceInfo d in deviceManager.DeviceInfos)
{
if (d.Type == WiaDeviceType.ScannerDeviceType)
{
firstScannerAvailable = d;
}
}
// Connect to the first available scanner
var device = firstScannerAvailable.Connect();
// Select the scanner
var scannerItem = device.Items[0];
// Retrieve a image in JPEG format and store it into a variable
var imageFile = (ImageFile)scannerItem.Transfer(FormatID.wiaFormatPNG);
//Save the image in some path with filename
var path = #"C:\Documents\scan.png";
if (File.Exists(path))
{
File.Delete(path);
}
// Save image !
imageFile.SaveFile(path);
I just have to remove the addition of lines in the file of log.
This is much more of a workaround since i have no idea about your scanner.
I would assume that all scanners has a drive where they store their scanned documents, like mine, So i would suggest that you read all available drives loop through them check for DriveType and VolumeLabel and then read it's files and copy the document where you want
Something like this :
foreach (var item in DriveInfo.GetDrives())
{
//VolumeLabel differs from a scanner to another
if (item.VolumeLabel == "Photo scan" && item.DriveType == DriveType.Removable)
{
foreach (var obj in Directory.GetFiles(item.Name))
{
File.Copy(obj, "[YOUR NEW PATH]");
break;
}
break;
}
}
Finaly a TWAIN application work with this scanner. I will work with that. I don't said why do that work with TWAIN and not with WIA but that the reality. Sorry for this waste of time. Thank you for the answers. Have a nice day.
I am currently solving this very problem. It seems the N7100A driver sets the Pages property of the device to 0, which should mean continous scanning, but the transfer method is unable to handle this value. You must set that property to 1:
var pages = 1;
// Not all devices have this property, but Fujitsu N7100A has.
device.Properties["Pages"]?.set_Value(ref pages);
I think the problem is here
var scannerItem = device.Items[0];
as WIA indexes are NOT zero based so it should be 1 instead
var scannerItem = device.Items[1];

Got stuck thinking in an idea that i got

First of all, sorry that I was unable to give a proper title.
I got stuck with an idea that's been with me today almost the whole day after searching and searching and searching, till it came to a point that I decided to ask it on Stackoverflow!
So here's where I am stuck:
(I am making an auto-installer currently coded in C# and it is Dutch. It works really awesome but I just need one thing to finish my base. For example:
You have 'multiple' objects selected in a checklistbox, those are read from the checklistbox itself, they get trimmed and they get launched after that.
Now that's all working, I wanted to add a waiting method, for example we got:
Malwarebytes & CCleaner as installation 'example'.
Now when both are checked, and I click start, it starts both of the programs.
What I want to do is: to tell the program to start one program, do your thing, once its finished (closed) it should go to the next.
But... There is a problem, my programs are started in an array, so it basically works if there are multiple objects checked, than it will start all of the checked objects. And I really have no idea how to reach the same thing which is basically :
If there are multiple objects selected, start the object(s), do your thing(auto-clicking etc.),once its closed and confirmed its closed, move on to the next object and do the same thing until its been completed. I would like to make it work with a progressbar, but never really looked into a progress bar as they seem confusing.
I have a piece of code that finds the Process ID so maybe I can do something with that, but the Process ID is never the same on the applications that I start, so when they start in an array I got kinda of an issue.
Could someone help me please figuring out what & how to code / do this?
here's the code i use to make this work :
string pad = Application.StartupPath;
foreach (string checkedItem in checkedListBox1.CheckedItems)
{
if (checkedItem.Contains("."))
{
string str = checkedItem;
if (str.Contains("."))
{
int index = str.IndexOf('.');
string folder = str.Substring(0, index);
try
{
bool started = false;
var process = new Process();
process.StartInfo.FileName = pad + "/data/" + folder + "/" + checkedItem;
started = process.Start();
var processID = process.Id;
var processNAAM = process.ProcessName;
textBox1.Text += "Gevonden - ID: " + processID + " NAAM: " + processNAAM + Environment.NewLine;
textBox1.Text += DateTime.Now.ToString("HH:mm:ss", System.Globalization.DateTimeFormatInfo.InvariantInfo) + " - " + "Installatie Keuze wordt opgestart." + Environment.NewLine;
process.WaitForExit();
}
catch (Exception)
{
}
}
}
}
First of all, you can make the code simpler and shorter by using the CheckedListBox's CheckedItems property. Secondly, there's no point to all your copying of strings from one to another. Strings are immutable in .NET - they never change. You can keep just one copy and cut from there.
Next, you can use the methods in System.IO.Path to cut the filename without the extension, or to build a full path without worrying about having too many or too few "/"'s.
Third, for your original question - just call WaitForExit on your Process object to make it wait before moving on with the list of processes.
Thirdly
foreach (string checkedItem in checkedListBox1.CheckedItems)
{
if (checkedItem.Contains("."))
{
string baseName = Path.GetFileNameWithoutExtension(checkedItem);
string processPath = Path.Combine(pad, "data", baseName, checkedItem);
Process process = Process.Start(processPath);
process.WaitForExit();
}
}
After the line where you start the process (process.Start()), simply add the following:
process.WaitForExit()
This will pause the containing thread until the target process has exited.

C# Problem Reading Console Output to string

i want to launch ffmpeg from my app and retrive all console output that ffmpeg produces. Thing seems obvious, i followed many forum threads/articles like this one but i have problem, though i follow all information included there I seem to end up in dead end.
String that should contain output from ffmpeg is always empty. I've tried to see where is the problem so i made simple c# console application that only lists all execution parameters that are passed to ffmpeg, just to check if problem is caused by ffmpeg itself. In that case everything work as expected.
I also did preview console window of my app. When i launch ffmpeg i see all the output in console but the function that should recieve that output for further processing reports that string was empty. When my param-listing app is launched the only thing I see is the expected report from function that gets output.
So my question is what to do to get ffmpeg output as i intended at first place.
Thanks in advance
MTH
This is a long shot, but have you tried redirecting StandardError too?
Here is a part of my ffmpeg wrapper class, in particular showing how to collect the output and errors from ffmpeg.
I have put the Process in the GetVideoDuration() function just so you can see everything in the one place.
Setup:
My ffmpeg is on the desktop, ffPath is used to point to it.
namespace ChildTools.Tools
{
public class FFMpegWrapper
{
//path to ffmpeg (I HATE!!! MS special folders)
string ffPath = System.Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "\\ffmpeg.exe";
//outputLines receives each line of output, only if they are not zero length
List<string> outputLines = new List<string>();
//In GetVideoDuration I only want the one line of output and in text form.
//To get the whole output just remove the filter I use (my search for 'Duration') and either return the List<>
//Or joint the strings from List<> (you could have used StringBuilder, but I find a List<> handier.
public string GetVideoDuration(FileInfo fi)
{
outputLines.Clear();
//I only use the information flag in this function
string strCommand = string.Concat(" -i \"", fi.FullName, "\"");
//Point ffPath to my ffmpeg
string ffPath = System.Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "\\ffmpeg.exe";
Process processFfmpeg = new Process();
processFfmpeg.StartInfo.Arguments = strCommand;
processFfmpeg.StartInfo.FileName = ffPath;
//I have to say that I struggled for a while with the order that I setup the process.
//But this order below I know to work
processFfmpeg.StartInfo.UseShellExecute = false;
processFfmpeg.StartInfo.RedirectStandardOutput = true;
processFfmpeg.StartInfo.RedirectStandardError = true;
processFfmpeg.StartInfo.CreateNoWindow = true;
processFfmpeg.ErrorDataReceived += processFfmpeg_OutData;
processFfmpeg.OutputDataReceived += processFfmpeg_OutData;
processFfmpeg.EnableRaisingEvents = true;
processFfmpeg.Start();
processFfmpeg.BeginOutputReadLine();
processFfmpeg.BeginErrorReadLine();
processFfmpeg.WaitForExit();
//I filter the lines because I only want 'Duration' this time
string oStr = "";
foreach (string str in outputLines)
{
if (str.Contains("Duration"))
{
oStr = str;
}
}
//return a single string with the duration line
return oStr;
}
private void processFfmpeg_OutData(object sender, DataReceivedEventArgs e)
{
//The data we want is in e.Data, you must be careful of null strings
string strMessage = e.Data;
if outputLines != null && strMessage != null && strMessage.Length > 0)
{
outputLines.Add(string.Concat( strMessage,"\n"));
//Try a Console output here to see all of the output. Particularly
//useful when you are examining the packets and working out timeframes
//Console.WriteLine(strMessage);
}
}
}
}

Transfer file from Windows Mobile device to...anywhere

I can't seem to find a solution to this issue. I'm trying to get my Compact Framework application on Windows Mobile 6 to have the ability to move a file on its local filesystem to another system.
Here's the solutions I'm aware of:
FTP - Problem with that is most of
the APIs are way to expensive to use.
HTTP PUT - As far as I have been able to find, I can't use anonymous PUT with IIS7, and that's the web server the system is running. (An extreme workaround for this would be to use a different web server to PUT the file, and have that other system transfer it to the IIS system).
Windows share - I would need authentication on the shares, and I haven't seen that a way to pass this authentication through windows mobile.
The last resort would be to require that the devices be cradled to transfer these files, but I'd really like to be able to have these files be transferred wirelessly.
FTP: define "too expensive". Do you mean performance or byte overhead or dollar cost? Here's a free one with source.
HTTP: IIS7 certainly supports hosting web services or custom IHttpHandlers. You could use either for a data upload pretty easily.
A Windows Share simply requires that you to P/Invoke the WNet APIs to map the share, but it's not terribly complex.
I ended up just passing information to a web server via a PHP script.
The options provided above just didn't work out for my situation.
Here's the gist of it. I've got some code in there with progress bars and various checks and handlers unrelated to simply sending a file, but I'm sure you can pick through it. I've removed my authentication code from both the C# and the PHP, but it shouldn't be too hard to roll your own, if necessary.
in C#:
/*
* Here's the short+sweet about how I'm doing this
* 1) Copy the file from mobile device to web server by querying PHP script with paramaters for each line
* 2) PHP script checks 1) If we got the whole data file 2) If this is a duplicate data file
* 3) If it is a duplicate, or we didn't get the whole thing, it goes away. The mobile
* device will hang on to it's data file in the first case (if it's duplicate it deletes it)
* to be tried again later
* 4) The server will then process the data files using a scheduled task/cron job at an appropriate time
*/
private void process_attempts()
{
Uri CheckUrl = new Uri("http://path/to/php/script?action=check");
WebRequest checkReq = WebRequest.Create(CheckUrl);
try
{
WebResponse CheckResp = checkReq.GetResponse();
CheckResp.Close();
}
catch
{
MessageBox.Show("Error! Connection not available. Please make sure you are online.");
this.Invoke(new Close(closeme));
}
StreamReader dataReader = File.OpenText(datafile);
String line = null;
line = dataReader.ReadLine();
while (line != null)
{
Uri Url = new Uri("http://path/to/php/script?action=process&line=" + line);
WebRequest WebReq = WebRequest.Create(Url);
try
{
WebResponse Resp = WebReq.GetResponse();
Resp.Close();
}
catch
{
MessageBox.Show("Error! Connection not available. Please make sure you are online.");
this.Invoke(new Close(closeme));
return;
}
try
{
process_bar.Invoke(new SetInt(SetBarValue), new object[] { processed });
}
catch { }
process_num.Invoke(new SetString(SetNumValue), new object[] { processed + "/" + attempts });
processed++;
line = dataReader.ReadLine();
}
dataReader.Close();
Uri Url2 = new Uri("http://path/to/php/script?action=finalize&lines=" + attempts);
Boolean finalized = false;
WebRequest WebReq2 = WebRequest.Create(Url2);
try
{
WebResponse Resp = WebReq2.GetResponse();
Resp.Close();
finalized = true;
}
catch
{
MessageBox.Show("Error! Connection not available. Please make sure you are online.");
this.Invoke(new Close(closeme));
finalized = false;
}
MessageBox.Show("Done!");
this.Invoke(new Close(closeme));
}
In PHP (thoroughly commented for your benefit!):
<?php
//Get the GET'd values from the C#
//The current line being processed
$line = $_GET['line'];
//Which action we are doing
$action = $_GET['action'];
//# of lines in the source file
$totalLines = $_GET['lines'];
//If we are processing the line, open the data file, and append this new line and a newline.
if($action == "process"){
$dataFile = "tempdata/SOME_KIND_OF_UNIQUE_FILENAME.dat";
//open the file
$fh = fopen($dataFile, 'a');
//Write the line, and a newline to the file
fwrite($fh, $line."\r\n");
//Close the file
fclose($fh);
//Exit the script
exit();
}
//If we are done processing the original file from the C# application, make sure the number of lines in the new file matches that in the
//file we are transferring. An expansion of this could be to compare some kind of hash function value of both files...
if($action == "finalize"){
$dataFile = "tempdata/SOME_KIND_OF_UNIQUE_FILENAME.dat";
//Count the number of lines in the new file
$lines = count(file($dataFile));
//If the new file and the old file have the same number of lines...
if($lines == $totalLines){
//File has the matching number of lines, good enough for me over TCP.
//We should move or rename this file.
}else{
//File does NOT have the same number of lines as the source file.
}
exit();
}
if($action == "check"){
//If a file with this unique file name already exists, delete it.
$dataFile = "tempdata/SOME_KIND_OF_UNIQUE_FILENAME.dat";
if(file_exists($dataFile)){
unlink($dataFile);
}
}
?>

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