I want to delete/empty the "Author" feature if you have any documents I have. This document can be in PDF format, it can be in Docx, it can be in any picture or video format. I did a run below but I'm getting an error. How can I fix this error? How can I find a different solution?
ShellObject tempFile = ShellObject.FromParsingName(filePath);
ShellPropertyWriter propertyWriter = tempFile.Properties.GetPropertyWriter();
propertyWriter.WriteProperty(SystemProperties.System.Author, new string[] { "Author" });
propertyWriter.Close();
The error I'm getting is this:
"System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt."
The framework I am using is net6.0,
Can you please help?
Related
This is a tricky question. I suspect it will require some advanced knowledge of file systems to answer.
I have a WPF application, "App1," targeting .NET framework 4.0. It has a Settings.settings file that generates a standard App1.exe.config file where default settings are stored. When the user modifies settings, the modifications go in AppData\Roaming\MyCompany\App1\X.X.0.0\user.config. This is all standard .NET behavior. However, on occasion, we've discovered that the user.config file on a customer's machine isn't what it's supposed to be, which causes the application to crash.
The problem looks like this: user.config is about the size it should be if it were filled with XML, but instead of XML it's just a bunch of NUL characters. It's character 0 repeated over and over again. We have no information about what had occurred leading up to this file modification.
We can fix that problem on a customer's device if we just delete user.config because the Common Language Runtime will just generate a new one. They'll lose the changes they've made to the settings, but the changes can be made again.
However, I've encountered this problem in another WPF application, "App2," with another XML file, info.xml. This time it's different because the file is generated by my own code rather than by the CLR. The common themes are that both are C# WPF applications, both are XML files, and in both cases we are completely unable to reproduce the problem in our testing. Could this have something to do with the way C# applications interact with XML files or files in general?
Not only can we not reproduce the problem in our current applications, but I can't even reproduce the problem by writing custom code that generates errors on purpose. I can't find a single XML serialization error or file access error that results in a file that's filled with nulls. So what could be going on?
App1 accesses user.config by calling Upgrade() and Save() and by getting and setting the properties. For example:
if (Settings.Default.UpgradeRequired)
{
Settings.Default.Upgrade();
Settings.Default.UpgradeRequired = false;
Settings.Default.Save();
}
App2 accesses info.xml by serializing and deserializing the XML:
public Info Deserialize(string xmlFile)
{
if (File.Exists(xmlFile) == false)
{
return null;
}
XmlSerializer xmlReadSerializer = new XmlSerializer(typeof(Info));
Info overview = null;
using (StreamReader file = new StreamReader(xmlFile))
{
overview = (Info)xmlReadSerializer.Deserialize(file);
file.Close();
}
return overview;
}
public void Serialize(Info infoObject, string fileName)
{
XmlSerializer writer = new XmlSerializer(typeof(Info));
using (StreamWriter fileWrite = new StreamWriter(fileName))
{
writer.Serialize(fileWrite, infoObject);
fileWrite.Close();
}
}
We've encountered the problem on both Windows 7 and Windows 10. When researching the problem, I came across this post where the same XML problem was encountered in Windows 8.1: Saved files sometime only contains NUL-characters
Is there something I could change in my code to prevent this, or is the problem too deep within the behavior of .NET?
It seems to me that there are three possibilities:
The CLR is writing null characters to the XML files.
The file's memory address pointer gets switched to another location without moving the file contents.
The file system attempts to move the file to another memory address and the file contents get moved but the pointer doesn't get updated.
I feel like 2 and 3 are more likely than 1. This is why I said it may require advanced knowledge of file systems.
I would greatly appreciate any information that might help me reproduce, fix, or work around the problem. Thank you!
It's well known that this can happen if there is power loss. This occurs after a cached write that extends a file (it can be a new or existing file), and power loss occurs shortly thereafter. In this scenario the file has 3 expected possible states when the machine comes back up:
1) The file doesn't exist at all or has its original length, as if the write never happened.
2) The file has the expected length as if the write happened, but the data is zeros.
3) The file has the expected length and the correct data that was written.
State 2 is what you are describing. It occurs because when you do the cached write, NTFS initially just extends the file size accordingly but leaves VDL (valid data length) untouched. Data beyond VDL always reads back as zeros. The data you were intending to write is sitting in memory in the file cache. It will eventually get written to disk, usually within a few seconds, and following that VDL will get advanced on disk to reflect the data written. If power loss occurs before the data is written or before VDL gets increased, you will end up in state 2.
This is fairly easy to repro, for example by copying a file (the copy engine uses cached writes), and then immediately pulling the power plug on your computer.
I had a similar problem and I was able to trace my problem to corrupted HDD.
Description of my problem (all related informations):
Disk attached to mainboard (SATA):
SSD (system),
3 * HDD.
One of the HDD's had a bad blocks and there were even problems reading the disk structure (directories and file listing).
Operation system: Windows 7 x64
file system (on all disks): NTFS
When the system tried to read or write to the corrupted disk (user request or automatic scan or any other reason) and the attempt failed, all write operations (to other disk's) were incorrect. The files created on system disk (mostly configuration files by another applications) were written and were valid (probably because the files were cashed in RAM) on direct check of file content.
Unfortunately, after a restart, all the files (written after the failed write/read access on corrupted drive) had the correct size, but the content of the files was 'zero byte' (exactly like in your case).
Try rule out hardware related problems. You can try to check 'copy' the file (after a change) to a different machine (upload to web/ftp). Or try to save specific content to a fixed file. When the check file on different will be correct, or when the fixed content file will be 'empty', the reason is probably on local machine. Try to change HW components, or reinstall the system.
There is no documented reason for this behavior, as this is happening to users but nobody can tell the origin of this odd conditions.
It might be CLR problem, although this is a very unlikely, the CLR doesn't just write null characters and XML document cannot contain null characters if there's no xsi:nil defined for the nodes.
Anyway, the only documented way to fix this is to delete the corrupted file using this line of code:
try
{
ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.PerUserRoamingAndLocal);
}
catch (ConfigurationErrorsException ex)
{
string filename = ex.Filename;
_logger.Error(ex, "Cannot open config file");
if (File.Exists(filename) == true)
{
_logger.Error("Config file {0} content:\n{1}", filename, File.ReadAllText(filename));
File.Delete(filename);
_logger.Error("Config file deleted");
Properties.Settings.Default.Upgrade();
// Properties.Settings.Default.Reload();
// you could optionally restart the app instead
}
else
{
_logger.Error("Config file {0} does not exist", filename);
}
}
It will restore the user.config using the Properties.Settings.Default.Upgrade();
again without null values.
I ran into a similar issue but it was on a server. The server restarted while a program was writing to a file which caused the file to contain all null characters and become unusable to the program writing/reading from it.
So the file looked like this:
The logs showed that the server restarted:
The corrupted file showed that it was last updated at the time of the restart:
I have the same problem, there is an extra "NUL" character at the end of serialized xml file:
I am using XMLWriter like this:
using (var stringWriter = new Utf8StringWriter())
{
using (var xmlWriter = XmlWriter.Create(stringWriter, new XmlWriterSettings { Indent = true, IndentChars = "\t", NewLineChars = "\r\n", NewLineHandling = NewLineHandling.Replace }))
{
xmlSerializer.Serialize(xmlWriter, data, nameSpaces);
xml = stringWriter.ToString();
var xmlDocument = new XmlDocument();
xmlDocument.LoadXml(xml);
if (removeEmptyNodes)
{
RemoveEmptyNodes(xmlDocument);
}
xml = xmlDocument.InnerXml;
}
}
I have an issue with a class library; I am preparing a library with an interface that represents a specific data storage signature. The purpose is to use the interface as a basis for implementing a number of specific classes storing configuration information in different formats (text files, xml files, etc.) while retaining the same usage profile to the application using it. I have a problem, though. In this case I am trying to embed an xml file as a resource - this file is one type of format to store configuration data. The file is located as an embedded resource in a subfolder to the project, as shown in the attached illustration.
In the following code snippet it is shown how I have implemented the functionality until now.
public ConfigInfoXmlSource()
{
if (!string.IsNullOrEmpty(Settings.Default.CurrentConfigFile))
FileNameAndPath = Settings.Default.CurrentConfigFile;
else
FileNameAndPath = DefaultConfigFileName + DefaultFileExtension;
// Prepare XML.
System.Reflection.Assembly a = Assembly.GetExecutingAssembly();
XmlDocument doc = new XmlDocument();
Stream manifestResourceStream =
a.GetManifestResourceStream("TestTool.Config.Config1.xml");
if (manifestResourceStream == null)
{
// ???
}
...
doc.Load(manifestResourceStream);
...
}
In the section marked "Prepare XML" I am trying to read a stream from the embedded resource. After the reading, it is tested whether a stream was indeed created. If the file is found, the manifestResourceStream will contain the xml data - so far so good. The problem arises if the file for some reason has been accidentally deleted - in that case I want to create a new file as an embedded resource to replace the deleted file. That is supposed to happen in the conditional in the part shown as "???".
I have tried everything I could think of, searched Google for answers, etc. - to no avail.
Does anyone have a clue to how this is accomplished? Any help will be greatly appreciated.
Thanks in advance.
Best regards.
If you have a embedded resource,it is built into your binaries.It is not an physical file,rather something which is present inside the built file(dll in this case).So,once it is included,I do not think it can ever be deleted. As per my knowledge embedded resource can only be set while building your project binaries and you can not explicitly do it at runtime as it is not needed due to reasons mentioned above.
Hey everyone just trying to make a program that browses video files and reads the title and description from the files metadata. I found some docs from microsoft here giving whats needed but how do I access these functions? what using namespaces are needed in c#? I would love any help that can be provided.
In that link you posted, scroll to the bottom and click "Shell Metadata Providers". There's more more information and some sample C++ code.
Here are some other relevant links:
Reading/Writing metadata of audio/video files
http://www.codeproject.com/Articles/14535/Accessing-WMF-metadata-with-C
https://social.msdn.microsoft.com/Forums/pt-BR/0f36a3b2-4d3d-4842-88a4-bea493bbbace/read-video-filemov-avi-mpg-etc-meta-data?forum=csharpgeneral
https://web.archive.org/web/20170225230114/https://stackoverflow.com/questions/7396265/c-sharp-to-read-properties-of-video-files
Sorry I can't give you anything more concrete, however it looks like some tag libraries (i.e. for reading MP3 metadata) may work as well, as the metadata for videos seems to be stored in a similar, if not identical, format. That being said, you can give TagLib# a shot.
https://www.nuget.org/packages/taglib/
I've made a simple C# code (portable to Unity, too) csatomreader. It's optimized for speed and can read the atoms over HTTP, too.
E.g. Get title:
using (FileStream stream = new FileStream(fileName, FileMode.Open))
{
var mp4Reader = new AtomReader(stream);
string value = mp4Reader.GetMetaAtomValue(AtomReader.TitleTypeName);
Console.WriteLine($"{atomTypeName}: {value}");
}
If you need to get more metadata values at once, then iterate over ParseAtoms(), e.g. see the GetMetaAtomValue() source.
I have created a button where it can upload all the pic files as well as the doc files and the PDF files in the system.
Here is the code for the following:
if (dlg.ShowDialog() == DialogResult.OK)
{
pictureBox2.Image = Image.FromFile(dlg.FileName);
pictureBox2.SizeMode = PictureBoxSizeMode.Zoom;
currentFileName = dlg.FileName;
button2.Enabled = true;
}
}
But i have a error poping out when i want upload a doc files. First of all is it possible to upload a doc file? if yes, then i have a issues showing out of memory in the following line of code
pictureBox2.Image = Image.FromFile(dlg.FileName);
PictureBox control is used only for showing images in a WinForm application (take a look at MSDN). To show .doc file contents in your application you have to use word or some workaround (like posted here)
The reason why you get that error is because a doc file is not a valid image format.
This is outlined in the documentation: http://msdn.microsoft.com/en-us/library/stf701f5.aspx
it is possible to upload a doc file but not in the context you want, i.e. using Image.FromFile and assign it to a picture box object.
http://msdn.microsoft.com/en-us/library/stf701f5.aspx
Out of Memory exception covered in that topic.
The FromFile method will throw an exception if the file type is invalid.
You should do necessary checks on the file type's compatibility first, not to mention wrap a try catch around this method to ensure you're coding as defensively as possible.
Please take reference at the link from MSDN. It will throw OutOfmemoryException when you loading a picture have not appropriate format.
To resolve your problem you should check format of the picture file more than loading directly as above.
Please reference at here to know how can you detect format of an image file.
To loading PDF or Word document you should take reference here.
currently i have been using the following code and i am using some dll files from pdfbox
FileInfo file = new FileInfo("c://aa.pdf");
PDDocument doc = PDDocument.load(file.FullName);
PDFTextStripper pdfStripper = new PDFTextStripper();
string text = pdfStripper.getText (doc);
richTextBox1.Text = qq;
using this code i can able to get text file but not in a correct format plz give me a some ideas
Extracting the text from a pdf file is anything but trivial.
To quote from th iTextSharp tutorial.
"The pdf format is just a canvas where
text and graphics are placed without
any structure information. As such
there aren't any 'iText-objects' in a
PDF file. In each page there will
probably be a number of 'Strings', but
you can't reconstruct a phrase or a
paragraph using these strings. There
are probably a number of lines drawn,
but you can't retrieve a Table-object
based on these lines. In short:
parsing the content of a PDF-file is
NOT POSSIBLE with iText."
There are several commercial applications which claim to be able to do it. Caveat Emptor.
There is also a free software library called Poppler http://poppler.freedesktop.org/ which is used by the pdf viewers of GNOME and KDE. It has a function called pdftotext() but I have no experience with it. It may be your best free option.
There is a blog article explaining the issues with PDF text extraction in general at http://pdf.jpedal.org/java-pdf-blog/bid/12670/PDF-text