我已经打了很长时间了，而且现在比以前好多了。我在WPF应用程序中有一段C＃代码，用于监视已知文件夹并在出现时打印该文件夹中的图像。文件夹结构如下：
这是一段代码：
namespace Something.InStoreExperience.SalesDeviceMonitor.Plugins
{
public class PrintImagesPlugin : MonitorPlugin
{
private readonly object _lock = new object();
protected override void DoWork(UpdateManager<DirectoryInfo> updateManager, ISalesDeviceMonitor salesDeviceMonitor)
{
if (!Enabled)
{
PrintLoggingSource.Log.Debug("PrintImagesPlugin disabled. Quitting.");
return;
}
//lock (_lock)
//{
try
{
List<string> printFolders;
lock (_lock)
{
//get all of our finished folders (that aren't already being printed) and try to print the images inside them.
printFolders = Directory.GetDirectories(updateManager.SomethingKnownFolders.PrintImages.Path)
.Where(d => !d.Contains("-InProgress") && !d.Contains("-Processing")).ToList();
if (!printFolders.Any())
return;
PrintLoggingSource.Log.Debug(string.Format("Found {0} 'not in progress' folders to print. Details: {1}{2}",
printFolders.Count().ToString(CultureInfo.InvariantCulture),
Environment.NewLine,
string.Join(" ", printFolders.Select(pf => (pf + Environment.NewLine)))));
printFolders.ForEach(pf => Directory.Move(pf, pf + "-Processing"));
printFolders = printFolders.Select(pf => pf + "-Processing").ToList();
}
foreach (var printFolder in printFolders)
{
PrintLoggingSource.Log.Debug(string.Format("Beginning processing of {0}.", printFolder));
var closurePrintFolder = printFolder;
var printImages = Directory.GetFiles(closurePrintFolder).Where(f => !f.EndsWith("Thumbs.db")).ToList();
if (!printImages.Any()) //if there are no images, log that fact and delete the folder
{
PrintLoggingSource.Log.Warn(string.Format("No files found to delete in {0}. Deleting folder.", closurePrintFolder));
LoggingSource.Log.Warn(string.Format("No files found to delete in {0}. Deleting folder.", closurePrintFolder));
_DeleteFolder(closurePrintFolder);
continue;
}
var totalPageCount = printImages.Count;
var currentPageIndex = 0;
PrintLoggingSource.Log.Debug(string.Format("Will attempt to print {0} pages.", totalPageCount.ToString(CultureInfo.InvariantCulture)));
using (var pd = new PrintDocument()) //using stmt is new
{
pd.DefaultPageSettings.PrinterSettings.PrinterName = SomethingApp.IseConfig.PrinterName;
pd.DefaultPageSettings.Margins = new Margins(0, 0, 0, 0);
pd.DefaultPageSettings.Color = false;
pd.PrintController = new StandardPrintController(); //new
PrintLoggingSource.Log.Debug(pd.PrintController.GetType().ToString());
pd.BeginPrint += (sender, args) => PrintLoggingSource.Log.Debug(string.Format("BeginPrint fired. Printing from folder: {0}", closurePrintFolder));
pd.EndPrint += (sender, args) => PrintLoggingSource.Log.Debug(string.Format("EndPrint fired. Printed from folder: {0}", closurePrintFolder));
pd.Disposed += (sender, args) => PrintLoggingSource.Log.Debug(string.Format("Disposed fired. Printed from folder: {0}", closurePrintFolder));
pd.QueryPageSettings += (sender, args) => PrintLoggingSource.Log.Debug(string.Format("QueryPageSettings fired. Are print settings valid: {0}", args.PageSettings.PrinterSettings.IsValid));
pd.PrintPage += (sender, args) =>
{
PrintLoggingSource.Log.Debug(string.Format("Starting to print page {0}", currentPageIndex.ToString(CultureInfo.InvariantCulture)));
PrintLoggingSource.Log.Debug("Using new using statement with the FileStream");
PrintLoggingSource.Log.Debug("FileName: " + printImages[currentPageIndex]);
using (var fs = new FileStream(printImages[currentPageIndex], FileMode.Open, FileAccess.ReadWrite))
{
using (var imageToPrint = Image.FromStream(fs, true, false))
{
//determine our scale and then make it a little smaller b/c there's still a small margin around the page
var scale = ((double)args.MarginBounds.Height / imageToPrint.Height) * .94;
args.Graphics.DrawImage(imageToPrint, 0, 0,
(int)Math.Floor(imageToPrint.Width * scale),
(int)Math.Floor(imageToPrint.Height * scale));
currentPageIndex++;
}
}
if (currentPageIndex < totalPageCount)
{
args.HasMorePages = true;
}
else
{
args.HasMorePages = false;
_DeleteFolder(closurePrintFolder);
}
};
if (pd.DefaultPageSettings.PrinterSettings.IsValid)
{
PrintLoggingSource.Log.Debug("Settings are valid. Calling the print() function.");
LoggingSource.Log.Info("Settings are valid. Calling the print() function.");
pd.Print();
}
else
{
var printerName = SomethingApp.IseConfig.PrinterName;
PrintLoggingSource.Log.Warn(string.Format("Printer {0} failed to print because of incorrect configuration.", printerName));
LoggingSource.Log.Warn(string.Format("Printer {0} failed to print because of incorrect configuration.", printerName));
}
}
}
}
catch (Exception ex)
{
PrintLoggingSource.Log.Error(ex);
LoggingSource.Log.Error(ex, "Print image failed to print");
}
//}
}
private void _DeleteFolder(string folderPath)
{
PrintLoggingSource.Log.Debug(string.Format("Printing complete. Deleting {0} directory.", folderPath));
LoggingSource.Log.Info(string.Format("Printing complete. Deleting {0} directory.", folderPath));
var dInfo = new DirectoryInfo(folderPath);
dInfo.Delete(true); //delete recursively
}
}
}
在机器重启后，此代码完美无缺，除了。机器重启后，这就是日志文件的样子：
2015-10-16 11:39:37:9026 Type: Verbose Id: 1 Host: SomeMachineName Message: Found 1 'not in progress' folders to print. Details:
C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\197399ba-05d5-4ce9-b00a-97123ed6ff26
2015-10-16 11:39:37:9026 Type: Verbose Id: 1 Host: SomeMachineName Message: Beginning processing of C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\197399ba-05d5-4ce9-b00a-97123ed6ff26-Processing.
2015-10-16 11:39:37:9026 Type: Verbose Id: 1 Host: SomeMachineName Message: Will attempt to print 1 pages.
2015-10-16 11:39:37:9026 Type: Verbose Id: 1 Host: SomeMachineName Message: System.Drawing.Printing.StandardPrintController
2015-10-16 11:39:38:1053 Type: Verbose Id: 1 Host: SomeMachineName Message: Settings are valid. Calling the print() function.
2015-10-16 11:39:38:1365 Type: Verbose Id: 1 Host: SomeMachineName Message: BeginPrint fired. Printing from folder: C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\197399ba-05d5-4ce9-b00a-97123ed6ff26-Processing
即使一次打印尝试失败，打印也能正常工作。以下是日志中成功打印作业的内容：
2015-10-16 11:56:00:2530 Type: Verbose Id: 1 Host: SomeMachineName Message: Found 1 'not in progress' folders to print. Details:
C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70
2015-10-16 11:56:00:2530 Type: Verbose Id: 1 Host: SomeMachineName Message: Beginning processing of C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing.
2015-10-16 11:56:00:2530 Type: Verbose Id: 1 Host: SomeMachineName Message: Will attempt to print 1 pages.
2015-10-16 11:56:00:2530 Type: Verbose Id: 1 Host: SomeMachineName Message: System.Drawing.Printing.StandardPrintController
2015-10-16 11:56:00:3308 Type: Verbose Id: 1 Host: SomeMachineName Message: Settings are valid. Calling the print() function.
2015-10-16 11:56:00:3465 Type: Verbose Id: 1 Host: SomeMachineName Message: BeginPrint fired. Printing from folder: C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing
2015-10-16 11:56:00:6746 Type: Verbose Id: 1 Host: SomeMachineName Message: QueryPageSettings fired. Are print settings valid: True
2015-10-16 11:56:01:0183 Type: Verbose Id: 1 Host: SomeMachineName Message: Starting to print page 0
2015-10-16 11:56:01:0183 Type: Verbose Id: 1 Host: SomeMachineName Message: Using new using statement with the FileStream
2015-10-16 11:56:01:0183 Type: Verbose Id: 1 Host: SomeMachineName Message: FileName: C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing\635690182882039735.png
2015-10-16 11:56:01:1747 Type: Verbose Id: 1 Host: SomeMachineName Message: Printing complete. Deleting C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing directory.
2015-10-16 11:56:01:2216 Type: Verbose Id: 1 Host: SomeMachineName Message: EndPrint fired. Printed from folder: C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing
2015-10-16 11:56:01:2528 Type: Verbose Id: 1 Host: SomeMachineName Message: Disposed fired. Printed from folder: C:\Users\UserName\Documents\Something\Apps\Print\PrintImages\81fb90cd-31bb-4abf-a73f-f67f83865d70-Processing
到目前为止，我已经尝试过了：
PrintDocument和StandardDocumentPrintController的代码，希望在那里找到明显的东西（我不是很成功）。
请帮助我提出理论/想法，了解为什么打印过程可能会在重新启动后 失败，而不是其他时间。我觉得我必须错过一些明显的东西。