Develop Reference

Get all metadata from an existing PDF using iText7

How can I retrieve all metadata stored in a PDF with iText7?
using (var pdfReader = new iText.Kernel.Pdf.PdfReader("path-to-a-pdf-file"))
{
var pdfDocument = new iText.Kernel.Pdf.PdfDocument(pdfReader);
var pdfDocumentInfo = pdfDocument.GetDocumentInfo();
// Getting basic metadata
var author = pdfDocumentInfo.GetAuthor();
var title = pdfDocumentInfo.GetTitle();
// Getting everything else
var someMetadata = pdfDocumentInfo.GetMoreInfo("need-a-key-here");
// How to get all metadata ?
}
I was using this with iTextSharp but I can't figure how to do it with the new iText7.
using (var pdfReader = new iTextSharp.text.pdf.PdfReader("path-to-a-pdf-file"))
{
// Getting basic metadata
var author = pdfReader.Info.ContainsKey("Author") ? pdfReader.Info["Author"] : null;
var title = pdfReader.Info.ContainsKey("Title") ? pdfReader.Info["Title"] : null;
// Getting everything else
var metadata = pdfReader.Info;
metadata.Remove("Author");
metadata.Remove("Title");
// Print metadata
Console.WriteLine($"Author: {author}");
Console.WriteLine($"Title: {title}");
foreach (var line in metadata)
{
Console.WriteLine($"{line.Key}: {line.Value}");
}
}
I am using version 7.1.1 of iText7.

In iText 7 the PdfDocumentInfo class unfortunately does not expose a method to retrieve the keys in the underlying dictionary.
But you can simply retrieve the Info dictionary contents by immediately accessing that dictionary from the trailer dictionary. E.g. for a PdfDocument pdfDocument:
PdfDictionary infoDictionary = pdfDocument.GetTrailer().GetAsDictionary(PdfName.Info);
foreach (PdfName key in infoDictionary.KeySet())
Console.WriteLine($"{key}: {infoDictionary.GetAsString(key)}");

There is problem with "UnicodeBig", "UTF-8" or "PDF" encoded strings.
For example, if PDF is created with Microsoft Word, then "/Creator" is unreadable encoded and needs to be converted:
.
iText7 has own function for that convert:
...ToUnicodeString().
But it is a Method of the PdfString object and PdfDictionary value (PdfObject) hast to be first casted to this PdfString type.
Complete solution as async, "unbreakable" and auto-disposed function:
public static async Task<(Dictionary<string, string> MetaInfo, string Error)> GetMetaInfoAsync(string path)
{
try
{
var metaInfo = await Task.Run(() =>
{
var metaInfoDict = new Dictionary<string, string>();
using (var pdfReader = new PdfReader(path))
using (var pdfDocument = new PdfDocument(pdfReader))
{
metaInfoDict["PDF.PageCount"] = $"{pdfDocument.GetNumberOfPages():D}";
metaInfoDict["PDF.Version"] = $"{pdfDocument.GetPdfVersion()}";
var pdfTrailer = pdfDocument.GetTrailer();
var pdfDictInfo = pdfTrailer.GetAsDictionary(PdfName.Info);
foreach (var pdfEntryPair in pdfDictInfo.EntrySet())
{
var key = "PDF." + pdfEntryPair.Key.ToString().Substring(1);
string value;
switch (pdfEntryPair.Value)
{
case PdfString pdfString:
value = pdfString.ToUnicodeString();
break;
default:
value = pdfEntryPair.Value.ToString();
break;
}
metaInfoDict[key] = value;
}
return metaInfoDict;
}
});
return (metaInfo, null);
}
catch (Exception ex)
{
if (Debugger.IsAttached) Debugger.Break();
return (null, ex.Message);
}
}

NAudio code holds lock on input file

My code below holds a lock on the input file preventing me from working with it later:
public static void ToWave_WMF(string source, string destination)
{
using (var reader = new MediaFoundationReader(source))
using (var rateSampler = new MediaFoundationResampler(reader, new WaveFormat(DefaultEncoding.SampleRate, reader.WaveFormat.Channels)))
using (var channelSampler = new MediaFoundationResampler(rateSampler, new WaveFormat(rateSampler.WaveFormat.SampleRate, DefaultEncoding.Channels)))
{
WaveFileWriter.CreateWaveFile(destination, channelSampler);
}
}
public static string BuildWavFile(string userFileLocation)
{
var sampleList = new List<ISampleProvider>();
try
{
// Add input file
var waveFile = AudioHelpers.ToWave_WMF(userFileLocation);
sampleList.Add(new AudioFileReader(waveFile));
WaveFileWriter.CreateWaveFile16(sirenWaveFile, new ConcatenatingSampleProvider(sampleList));
}
finally
{
foreach (var sample in sampleList)
{
((AudioFileReader)sample).Dispose();
}
}
return sirenWaveFile;
}
Am I using resources wrong? Why is this lock being held? If I delete the file after toWave_WMF() there is no issue. If I use sampleList.Add(new AudioFileReader(userFileLocation)); I also dont have any issues deleting the userFile.

UWP Event on content changed

I want to observe on a folder. Like i want a Event When the content is changed.
I found this
var options = new Windows.Storage.Search.QueryOptions
{
FolderDepth = Windows.Storage.Search.FolderDepth.Deep
};
var query = Folder.CreateFileQueryWithOptions(options);
query.ContentsChanged += QueryContentsChanged;
var files = await query.GetFilesAsync();
private void QueryContentsChanged(IStorageQueryResultBase sender, object args)
{
//Code here
}
But the problem with this is I can't find which file caused the event and i even can't know what caused the Event (Like Modify , Create , Delete or Rename of file) How to get these details?
I used this code
public async void MonitorFolder()
{
var options = new Windows.Storage.Search.QueryOptions
{
FolderDepth = Windows.Storage.Search.FolderDepth.Deep
};
var query = Folder1.CreateFileQueryWithOptions(options);
query.ContentsChanged += QueryContentsChanged;
var files = await query.GetFilesAsync();
await addtoOld(Folder1, Old);
}
private async void addtoOld(StorageFolder folder1, List<FDate> old)
{
var files = await folder1.GetFilesAsync();
foreach (var file in files)
{
BasicProperties basicProperties = await file.GetBasicPropertiesAsync();
FDate f = new FDate
{
Path = file.Path,
Id = file.FolderRelativeId,
Modified = basicProperties.DateModified,
Change = ChangeType.NoChange,
FileType = Type.File
};
old.Add(f);
}
var folders = await folder1.GetFoldersAsync();
foreach (var folder in folders)
{
BasicProperties basicProperties = await folder.GetBasicPropertiesAsync();
FDate f = new FDate
{
Path = folder.Path,
Id = folder.FolderRelativeId,
Modified = basicProperties.DateModified,
Change = ChangeType.NoChange,
FileType = Type.Folder
};
old.Add(f);
addtoOld(folder, old);
}
return;
}
private async void QueryContentsChanged(IStorageQueryResultBase sender, object args)
{
New.Clear();
List<FDate> changed = new List<FDate>();
await addtoOld(Folder1, New);
foreach(var f in New)
{
var f1 = getFile(f);
if (f1 != null)
{
if (f1.Modified < f.Modified)
{
f1.Change = ChangeType.Modified;
changed.Add(f1);
}
Old.Remove(f1);
}
else
{
f.Change = ChangeType.Created;
changed.Add(f);
}
}
foreach (var f in Old)
{
f.Change = ChangeType.Deleted;
changed.Add(f);
}
Old = New;
foreach (var f in changed)
{
if(f.FileType== Type.File)
{
if (f.Change == ChangeType.Modified)
{
//code here
}
if(f.Change == ChangeType.Created)
{
//Created code here
}
if(f.Change == ChangeType.Deleted)
{
//Deleted code here
}
}
else
{
if (f.Change == ChangeType.Created)
{
//Created code here
}
if(f.Change == ChangeType.Deleted)
{
//Deleted code here
}
}
}
private FDate getFile(FDate f)
{
foreach(var fi in Old)
{
if (f.Name == fi.Name)
return fi;
}
return null;
}
This code is not working properly I looks like it is because the addtoOld is async The code can't be substituted because it is recursive. and the function can't be made sync it has many await how do i solve this?
Note:OLD and New are Lists ChangeType and Type are enums

According to the following blog post, there is unfortunately no way to identify the reason of the event and there is also no information about affected items.
File system change notifications in WinRT: http://lunarfrog.com/blog/filesystem-change-notifications
So I guess you will have to go through all files and check their Properties property to determine when each file was last modified, created etc.: https://learn.microsoft.com/en-us/uwp/api/windows.storage.storagefile

Determine if a Database is "Equal" to a DacPackage

Is there a way to use the SQL Server 2012 Microsoft.SqlServer.Dac Namespace to determine if a database has an identical schema to that described by a DacPackage object? I've looked at the API docs for DacPackage as well as DacServices, but not having any luck; am I missing something?

Yes there is, I have been using the following technique since 2012 without issue.
Calculate a fingerprint of the dacpac.
Store that fingerprint in the target database.
The .dacpac is just a zip file containing goodies like metadata, and
model information.
Here's a screen-grab of what you will find in the .dacpac:
The file model.xml has XML structured like the following
<DataSchemaModel>
<Header>
... developer specific stuff is in here
</Header>
<Model>
.. database model definition is in here
</Model>
</<DataSchemaModel>
What we need to do is extract the contents from <Model>...</Model>
and treat this as the fingerprint of the schema.
"But wait!" you say. "Origin.xml has the following nodes:"
<Checksums>
<Checksum Uri="/model.xml">EB1B87793DB57B3BB5D4D9826D5566B42FA956EDF711BB96F713D06BA3D309DE</Checksum>
</Checksums>
In my experience, this <Checksum> node changes regardless of a schema change in the model.
So let's get to it.
Calculate the fingerprint of the dacpac.
using System.IO;
using System.IO.Packaging;
using System.Security.Cryptography;
static string DacPacFingerprint(byte[] dacPacBytes)
{
using (var ms = new MemoryStream(dacPacBytes))
using (var package = ZipPackage.Open(ms))
{
var modelFile = package.GetPart(new Uri("/model.xml", UriKind.Relative));
using (var streamReader = new System.IO.StreamReader(modelFile.GetStream()))
{
var xmlDoc = new XmlDocument() { InnerXml = streamReader.ReadToEnd() };
foreach (XmlNode childNode in xmlDoc.DocumentElement.ChildNodes)
{
if (childNode.Name == "Header")
{
// skip the Header node as described
xmlDoc.DocumentElement.RemoveChild(childNode);
break;
}
}
using (var crypto = new SHA512CryptoServiceProvider())
{
byte[] retVal = crypto.ComputeHash(Encoding.UTF8.GetBytes(xmlDoc.InnerXml));
return BitConverter.ToString(retVal).Replace("-", "");// hex string
}
}
}
}
With this fingerprint now available, pseudo code for applying a dacpac can be:
void main()
{
var dacpacBytes = File.ReadAllBytes("<path-to-dacpac>");
var dacpacFingerPrint = DacPacFingerprint(dacpacBytes);// see above
var databaseFingerPrint = Database.GetFingerprint();//however you choose to do this
if(databaseFingerPrint != dacpacFingerPrint)
{
DeployDacpac(...);//however you choose to do this
Database.SetFingerprint(dacpacFingerPrint);//however you choose to do this
}
}

Here's what I've come up with, but I'm not really crazy about it. If anyone can point out any bugs, edge cases, or better approaches, I'd be much obliged.
...
DacServices dacSvc = new DacServices(connectionString);
string deployScript = dacSvc.GenerateDeployScript(myDacpac, #"aDb", deployOptions);
if (DatabaseEqualsDacPackage(deployScript))
{
Console.WriteLine("The database and the DacPackage are equal");
}
...
bool DatabaseEqualsDacPackage(string deployScript)
{
string equalStr = string.Format("GO{0}USE [$(DatabaseName)];{0}{0}{0}GO{0}PRINT N'Update complete.'{0}GO", Environment.NewLine);
return deployScript.Contains(equalStr);
}
...
What I really don't like about this approach is that it's entirely dependent upon the format of the generated deployment script, and therefore extremely brittle. Questions, comments and suggestions very welcome.

#Aaron Hudon answer does not account for post script changes. Sometimes you just add a new entry to a type table without changing the model. In our case we want this to count as new dacpac. Here is my modification of his code to account for that
private static string DacPacFingerprint(string path)
{
using (var stream = File.OpenRead(path))
using (var package = Package.Open(stream))
{
var extractors = new IDacPacDataExtractor [] {new ModelExtractor(), new PostScriptExtractor()};
string content = string.Join("_", extractors.Select(e =>
{
var modelFile = package.GetPart(new Uri($"/{e.Filename}", UriKind.Relative));
using (var streamReader = new StreamReader(modelFile.GetStream()))
{
return e.ExtractData(streamReader);
}
}));
using (var crypto = new MD5CryptoServiceProvider())
{
byte[] retVal = crypto.ComputeHash(Encoding.UTF8.GetBytes(content));
return BitConverter.ToString(retVal).Replace("-", "");// hex string
}
}
}
private class ModelExtractor : IDacPacDataExtractor
{
public string Filename { get; } = "model.xml";
public string ExtractData(StreamReader streamReader)
{
var xmlDoc = new XmlDocument() { InnerXml = streamReader.ReadToEnd() };
foreach (XmlNode childNode in xmlDoc.DocumentElement.ChildNodes)
{
if (childNode.Name == "Header")
{
// skip the Header node as described
xmlDoc.DocumentElement.RemoveChild(childNode);
break;
}
}
return xmlDoc.InnerXml;
}
}
private class PostScriptExtractor : IDacPacDataExtractor
{
public string Filename { get; } = "postdeploy.sql";
public string ExtractData(StreamReader stream)
{
return stream.ReadToEnd();
}
}
private interface IDacPacDataExtractor
{
string Filename { get; }
string ExtractData(StreamReader stream);
}

How to avoid using foreach loop to get the filelist for different reason

Here what am trying to do:
I have a remote server (e.g:svr01,svr02,svr03). Using GetFileList to read the directory get all the files and match with the file name I have then copy to my local drive.
If any files matched then am adding them to an XML file also.
I was trying to do like below
class Program
{
static void Main(string[] args)
{
var getfiles = new fileshare.Program();
string realname = "*main*";
string Location = "SVR01";
bool anymatch = false;
foreach (var file in getfiles.GetFileList(realname,Location))
{anymatch=true;}
if (anymatch == true)
{ baseMeta(); }
foreach (var file in getfiles.GetFileList(realname,Location))
{getfiles.copytolocal(file.FullName); }
}
private FileInfo[] GetFileList(string pattern,string Location)
{
try
{
switch (Location)
{
case "SVR01":
{
var di = new DirectoryInfo(#"\\SVR01\Dev");
return di.GetFiles(pattern);
}
case "SVR02":
{
var di = new DirectoryInfo(#"\\SVR02\Dev");
return di.GetFiles(pattern);
}
case "SVR03":
{
var di = new DirectoryInfo(#"\\SVR03\Prod");
return di.GetFiles(pattern);
}
default: throw new ArgumentOutOfRangeException();
}
}
catch(Exception ex)
{ Console.Write(ex.ToString());
return null;
}
}
private void copytolocal(string filename)
{
string nameonly = Path.GetFileName(filename);
File.Copy(filename,Path.Combine(#"c:\",nameonly),true);
}
private void baseMeta()
{
XmlWriter xmlWrite = XmlWriter.Create(#"c:\basexml");
xmlWrite.WriteStartElement("job");
xmlWrite.WriteElementString("Name", "test");
xmlWrite.WriteElementString("time", DateTime);
xmlWrite.Close();
}
}
but this piece of code worries me because am doing the same process two times, any one please guide me how to avoid this.
foreach (var file in getfiles.GetFileList(realname,Location))
{
anymatch=true;}
if (anymatch == true)
{
baseMeta();
}
foreach (var file in getfiles.GetFileList(realname,Location))
{
getfiles.copytolocal(file.FullName);
}
}
Even am trying to find out if it match anyfile then i quit the first foreach loop generate the basemeta() then goes to next foreach loop to do the rest of the process.

Using LINQ you should be able to easily change your posted code into:
var getfiles = new fileshare.Program();
string realname = "*main*";
string Location = "SVR01";
var fileList = getFiles.GetFileList(realname, Location);
var anymatch = fileList.Any();
if (anymatch) // Or possibly `if (fileList.Any())` if anymatch isn't
// really used anywhere else
baseMeta();
foreach (var file in getfiles.GetFileList(realname,Location))
getfiles.copytolocal(file.FullName);
You'll get the greatest benefit by replacing your GetFileList method with:
private IEnumerable<FileInfo> GetFileList(string pattern,string Location)
{
string directory = string.Empty;
switch (Location)
{
case "SVR01":
directory = #"\\SVR01\Dev";
break;
case "SVR02":
directory = #"\\SVR02\Dev";
break;
case "SVR03":
directory = #"\\SVR03\Prod");
break;
default:
throw new ArgumentOutOfRangeException();
}
DirectoryInfo di = null;
try
{
di = new DirectoryInfo(directory);
}
catch(Exception ex)
{
Console.WriteLine(ex.Message);
yield break;
}
foreach(var fi in di.EnumerateFiles(pattern))
yield return fi;
}

Use this
var files = getfiles.GetFileList(realname, Location);
if (files.Length > 0)
{
baseMeta();
foreach(var file in files)
{
getfiles.copytolocal(file.FullName);
}
}

Try this:
Create method to check the file existence and do all in single loop.
your statement is not much clear that when you will copy or not.. use
your condition on which you want to copy or create xml entry..
What is your AnyMatch?? If you want to check that Is there any file then use
var fileList = getfiles.GetFileList(realname,Location);
if( fileList.Count() > 0)
{
baseMeta();
}
foreach (var file in fileList)
{
// copy the file if match does not exist..
getfiles.copytolocal(file.FullName);
}
But Foreach loop through collection if it have any item. so you need not to care about the count of the files..
If you want to do entry on every copy as per your code then why you need to check anyMatch etc. It will create entry on every file copy.
foreach (var file in getfiles.GetFileList(realname,Location))
{
baseMeta();
// copy the file
getfiles.copytolocal(file.FullName);
}