WPF WebBrowser free up the viewing process - c#

Have a problem when i want to pass another file (pdf) to view in WebBrowser, before if exists try to delete it, but it is impossible. The error is: "System.IO.IOException: The process cannot access the file 'C: \ Users ...".
I tried to use Dispose() and create a new web browser (i can't see again the file), set Source = null, Navigate("about:blank") but nothing.
I need to delete the file beacause i can put another file in WebBrowser.
Thanks!
if (File.Exists(file))
{
File.Delete(file);
}
file= System.IO.Path.GetTempPath() + "file.pdf";
}
if (!string.IsNullOrEmpty(file)) this.webBrowser.Navigate("file:\\" + file);

Related

Embedding Text File in Resources C#

I'm attempting to do two things. I want to embed a text file into my project so that I can utilise it and modify it, but at the same time I don't want to have to package it when I send the project out to users (I.E included in the exe file).
I've had a look around and there's been multiple questions already but I just cant seem to get any to work. Here's the steps I've taken so far;
Added the text file to my "Resources Folder"
Build action to "Content" and output directory to "Do not copy"
I then try to access the file in my code;
if (File.Exists(Properties.Resources.company_map_template))
{
MessageBox.Show("Test");
var objReader = new StreamReader(Properties.Resources.company_map_template);
string line = "";
line = objReader.ReadToEnd();
objReader.Close();
line = line.Replace("[latlong]", latitude + ", " + longitude);
mapWebBrowser.NavigateToString(line);
}
The MessageBox never appears which to me means that it cannot find the file and somewhere somehow I've done something wrong. How can I add the file into my project so I don't need to distribute with an exe whilst being able to access it in code?
I would use the following:
BuildAction to None (not needed)
and add your file to Resources.resx under files (using DragAndDrop from SolutionExplorer to opened Resources.resx)
Access to your Text:
using YOURNAMESPACE.Configuration.Properties;
string fileContent = Resources.company_map_template;
Then you're done. You don't need to access through StreamReader

Replacing PDF fails. Even with File.Delete() success when opened in Edge-Browser

The goal is to replace a PDF-File which is currently saved on disk.
I am deleting the current PDF file from disk, then recreating a new one. This works fine unless the PDF is currently opened in the Microsoft Edge Browser.
// Try delete PDF-File (which is opened in Edge Browser)
var info = new FileInfo(pathToPdf);
if (info.Exists)
{
try
{
info.Delete();
// Same thing with the File.Delete call
//File.Delete(path);
Console.WriteLine("Success.");
}
catch (Exception)
{
Console.WriteLine("Failed.");
return;
}
}
We get a "Success" print out even though the file is opened in Edge. If it were opened in Adobe Reader it would throw an exception (File in use).
Let's create a new file. (For demonstration purposes a text file with a .pdf ending)
try
{
using (var writer = File.CreateText(pathToPdf))
{
writer.Write("Foo");
writer.Flush();
Console.WriteLine("Success.");
}
}
catch (Exception e)
{
Console.WriteLine("Failed.");
return;
}
I expected to be able to create a new file, since the Delete() didn't fail. Yet I get an UnauthorizedAccessException: "Access to the path 'XYZ' is denied."
As a workaround I can recheck if the file exists after deleting it.
var newInfo = new FileInfo(pathToPdf);
if (newInfo.Exists)
// Delete failed
But why would I need to do this? Shouldn't FileInfo.Delete() or File.Delete(path) fail in the first place?
Notes:
Tested on Windows 10 Pro with .Net Framework 4.5.1
The file is still visible in the File-Explorer with its original filesize after it was deleted by code (while opened in Edge).
When closing the Edge Browser after deleting the file by code, the file vanishes from the File-Explorer and I can create a new file programatically.
This problem occurs only with PDFs being opened in Edge. When using a Text-File instead the Text-File gets deleted properly.
Any clarification and help is appreciated.
Best Chris
If the file does not exist, FileInfo.Delete() does nothing.
From msdn
WinNt4Family
Delete does not delete a file that is open for normal I/O or a file that is memory-mapped.
You get an UnauthorizedAccessException when the path is a directory.
If FILE_SHARE_DELETE is set on the handle by Edge, then File.delete() can be called with success by another process even when the handle exists. The file is then marked for deletion and deleted after the handle is closed. Until then, it is still visible in the Explorer, but not accessible anymore.
For a more detailed explanation, see this SO post:
Odd behaviour when deleting Files with Files.delete()

C# OpenFileDialog open zip folder containing single file?

I have an application which currently provides the user with the ability to view a PDF file inside the application by using File->Open, browsing to the location of the PDF file using a Microsoft.Win32.OpenFileDialog, and then displaying that PDF file in a System.Windows.Controls.WebBrowser in the GUI.
I am creating the OpenFileDialog and setting the file extensions it can open using:
/*Create Open File dialog */
Microsoft.Win32.OpenFileDialog OFDlg = new Microsoft.Win32.OpenFileDialog();
/*Set filter for file extension and default file extension */
OFDlg.DefaultExt = ".pdf";
OFDlg.Filter = "PDF Documents (.pdf)|*.pdf";
I now want to extend this, so that the user can open a ZIP folder containing a single PDF document, and display that PDF document in the same way that I am above.
I tried changing the filter to allow .zip files, i.e.
OFDlg.DefaultExt = ".pdf|.zip";
OFDlg.Filter = "PDF Documents (.pdf)|*.pdf|ZIP|*.zip";
but when I browse to the location of the .zip file in the OpenFileDialog, the .zip folder is not displayed there- only normal folders and PDF documents (other documents in that directory, such as .doc & .xls are not displayed in the OpenFileDialog).
My reason for wanting to be able to open the contents of a .zip file directly from the .zip, rather than navigating to that file itself, is so that I can add public/private key encryption to the .zip, so that its contents can only be read securely.
I know that there could in theory be problems if the .zip contains more than one file, but I intend to send each encrypted file in its own zip folder, so it can be assumed that any zip file that the user is trying to open contains a single .pdf, and nothing else.
So my questions are:
How can I make .zip folders visible from the OpenFileDialog?
How can I make the selection of that .zip folder automatically open and display its contents (a single PDF file) in the System.Window.Controls.WebBrowser that I am currently using to display PDFs in my GUI?
Edit 1
I tried changing my OpenFile() method to the following code:
/*Set filter for file extension and default file extension */
OFDlg.DefaultExt = ".pdf";
OFDlg.DefaultExt = ".zip";
OFDlg.Filter = "PDF Documents (.pdf)|*.pdf";
OFDlg.Filter = "ZIP Folders (.ZIP)|*.zip";
but when I now run my application, and browse to the same location, although the .zip folder is now shown in the OpenFileDialog, the .pdf files no longer are... and if I double click the .zip folder, my application breaks, and I get a runtime error on the line
PdfPanel.OpenFile(docFP);
which says:
An unhandled exception of type 'System.AccessViolationException' occurred in MoonPdfLib.dll
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
I guess that's to do with the MoonPDF library that I'm using to read the PDFs being unable to handle the .zip extension?
How would I resolve this to be able to open the PDF inside the ZIP?
Edit 2
Ok, so I've resolved the issue about only being able to see either the PDF files or the .ZIP folders (not both at the same time), by moving the functionality into two separate methods- one to display the PDF direct from the PDF's filepath, and another to display the PDF from the path of the .ZIP folder holding it.
The method for displaying the PDFs directly currently works (it is essentially the code in the first bit of code I've quoted). However the method for displaying the PDFs from the ZIP currently doesn't work...
I understand the reason for this- it's because I am passing a .zip folder to the OpenFile method... The code for this method currently looks like this:
private void openZipMenuItem_click(object sender, RoutedEventArgs e)
{
Microsoft.Win32.OpenFileDialog OZipDlg = new Microsoft.Win32.OpenFileDialog();
OZipDlg.DefaultExt = ".zip";
OZipDlg.Filter = "ZIP Folder (.zip)|*.zip";
Nullable<bool> result = OZipDlg.ShowDialog();
if (result == true)
{
/*Open document */
string filename = OZipDlg.FileName;
//fnTextBox.Text = filename;
zipFP = OZipDlg.FileName;
/*browser.Navigate(docFP); ERF (27/05/2016 # 0935) Comment this line- I want to use PdfPanel to open docFP, not browser */
Console.WriteLine("Panel height: " + PdfPanel.ActualHeight);
PdfPanel.OpenFile(zipFP);
}
}
When I try to call this function to open a .zip, I get a runtime exception which says:
AccessViolationException was unhandled
An unhandled exception of type 'System.AccessViolationException' occurred in MoonPdfLib.dll
Additional information: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
I understand that I can't display a Zip folder in the PdfPanel (which is a MoonPdfPanel that I am using from the MoonPdfLibrary), so I know that I will get an exception here.
How can I pass the contents of zipFP to the call to PdfPanel.OpenFile(), rather than passing zipFP itself to it?
Edit 3
Ok, so my code is currently extracting the PDF file successfully from the ZIP folder when I open it- I can see that it is copied to the directory I have specified. I am now trying to get the PDF to be displayed automatically in the PDF Panel on my application- I've done this by adding the following code:
try{
string extractPath = #"C:\Documents";
using(ZipArchivev zip = ZipFile.Open(zipFP, ZipArchiveMode.Read))
foreach(ZipArchiveEntry entry in zip.Entries){
try{
ZipFile.ExtractToDirectory(zipFP, extractPath);
Console.WriteLine("zipFP: " + zipFP);
}catch(System.IOException){
Console.WriteLine("File already exists...");
}
}
string ExtractedPDF = string.Concat(extractPath, zipFP);
PdfPanel.OpenFile(ExtractedPDF);
}catch(AccessViolationException ex){
Console.WriteLine("Can't display a zip in the PDF panel..." + ex.InnerException);
}
But when my code tries to execute the line PdfPanel.OpenFile(ExtracedPDF);, I get an exception that says:
FileNotFoundException was unhandled | An unhandled exception of type 'System.IO.FileNotFoundException' occurred in MoonPdfLib.dll'
I understand that this is happening because the variable I am trying to display in the PDFPanel, ExtractedPDF actually holds the path of the folder containing the PDF, and not the PDF itself- How do I give it the name of the PDF file, when I don't actually know what the PDF file will be called?
Here is something works similar to your requests, the logic behind the code is:
Only display zip and pdf files in the OpenFileDialog
If user selected a pdf file, show it in the panel
If user selected a zip file, change the directory of the OpenFileDialog to the zip file(treat it like a folder)
Example code (working code....):
OpenFileDialog ofd = new OpenFileDialog();
ofd.Filter = "PDF files (.pdf)|*.pdf;*.zip";
ofd.ShowDialog();
//reopen OpenFileDialog if it is zip file. this part can be improved.
if (ofd.FileName.EndsWith(".zip"))
{
ofd.InitialDirectory = ofd.FileName;
ofd.ShowDialog();
}
//if it's a PDF, note that you don't really need this check,
//as the only file can reache here will be a PDF,
//and it can be the temporary file that inside a zip.
if(ofd.FileName.EndsWith(".pdf"))
{
//show it in your PdfPanel
}
Edit, based on your new comments and added code. you need to change your code to the following as your current code is mistaken directory with the file:
try{
string extractPath = #"C:\Documents";
string ExtractedPDF ="";
using(ZipArchivev zip = ZipFile.Open(zipFP, ZipArchiveMode.Read))
foreach(ZipArchiveEntry entry in zip.Entries){
try{
ExtractedPDF= Path.Combine(extractPath, entry.FullName);
entry.ExtractToFile(ExtractedPDF,true);
}catch(System.IOException){
Console.WriteLine("error during extraction...");
}
}
if( System.IO.File.Exists(ExtractedPDF))
{
PdfPanel.OpenFile(ExtractedPDF);
}
}catch(AccessViolationException ex){
Console.WriteLine("Can't display a zip in the PDF panel..." + ex.InnerException);
}
If you want to support multiple file formats in an open file dialog, you need to add a third (or better first) option, that aggregates all supported file extensions:
OFDlg.Filter = "Supported file formats|*.pdf;*.zip|PDF Documents|*.pdf|ZIP files|*.zip";
First, regarding showing the files in the open file dialog. Your initial method for doing this was correct. Your updated code now first sets the filter to show PDFs, then replaces that filter with one that shows zip files. The standard file open dialog isn't designed to show different file types at the same time. The right way to handle that is to give the user the option for which file types they want to show.
Typically, an "All files" option is added as well (with . as the search pattern). This way if the file type the user wants to open isn't available in the list, they can see it regardless.
As for opening the PDF file that is in the zip file, you need to take are of extracting the PDF file yourself. This question has some options for how to do that.

WebClient.FileDownlOad GIVIn error that the file a is accessed by another process

I am trying to download a file using webclient method DownloadFile But its giving me error that
The process cannot access the file '...\d915877c-cb7c-4eeb-97d8-41d49b75aa27.docx' because it is being used by another process.
But when I open the file by clicking it, it opening.
There are same question requesting same info but none are accepted answers.
any help will be appreciated
It may be oS that is not letting file go. Whatever it is but after searching a lot I am unable to find solution
Here is the code to create a file
Document d = new Document();
d.Save(HttpContext.Current.Server.MapPath(#"Invoice\" + iname + ".docx"));
I am using aspose word dll
and following way I am accessing it
using (var client = new System.Net.WebClient())
{
client.UseDefaultCredentials = true;
client.DownloadFile(Server.MapPath("invoice/" + Request.QueryString["id"].ToString() + ".docx"),Server.MapPath("invoice/" +Request.QueryString["id"].ToString() + ".docx"));
client.Dispose();
}
and BTW its giving same error even to files that are not creaated using code.
Give a different path where to save the download file which is different from the download source path. If you want to replace the file do it after disposing the webclient by using File.replace() method.
string downloadPath = "Your download path";
string destinationPath = "the path where the file should be saved";`//this should be different from "download path"
File.Download(downloadPath,destinationPath);

WebBrowser control in windows form application using C#

I am trying to create a form with webbrowser control. I am trying to open a local html file in the webbrowser control. I have the html file in Help_Print folder, so I am using the code below to specify the Url of the webbrowser.
wbPrint.Url = new Uri("file:///" + Application.StartupPath + "\\Help_Print\\help.html");
When the form shows the webbrowser control has an error "This program cannot display the webpage". I have checked the file and folder location.
But when I try this:
wbPrint.Url = new Uri("file:///" + Application.StartupPath + "/help.html");
after copying the html file to the application startup location it works properly.
Can anyone please explain why is this happening, as I want to keep all html file in a separate folder.
Don't use black-slashes in file urls. See the bizarre and unhappy story of file urls.
I found a solution to my problem even-though I am not sure why my previous code was not working. I changed two thing:
(i) I remove Uri, as I was suggested in answer to a different question of mine, that for local html files I am not required to use Uri. So here is the code that work.
String sitePath = null;
try
{
sitePath = Application.StartupPath + #"\Print_Help\help.html";
wbHelp.Navigate(sitePath);
}
catch (Exception exp)
{
MessageBox.Show(exp.ToString() + "\nSite Path: " + sitePath);
return false;
}
return true;
(ii) The other thing I did was to create the Print_Help folder manually. Previously it was created when I Build my Project as the html file was marked the property Copy to Output Directory as Copy Always.
I think the second change has more to do with my problem solution than the first. Please comment if you understand the logic.
use syntax: file://c:/xyz.html

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