Silverlight import App.xaml from dynamically xap loaded - silverlight

Is there any way to access app.xaml resources of an imported XAP file (from host silverlight app) ???
Or better, import guest app.xaml into Host app.xaml
Problem is that in the imported Silverlight application, I lost all app.xaml resources, and I just see host resources... I would like to merge them...
It's possible?
I load XAP in this way
private void wc_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)
{
var manifestStream = Application.GetResourceStream(
new StreamResourceInfo(e.Result, null),
new Uri("AppManifest.xaml", UriKind.Relative));
string appManifest = new StreamReader(manifestStream.Stream).ReadToEnd();
string assemblyName =m_rootAssembly + ".dll";
XmlReader reader = XmlReader.Create(new StringReader(appManifest));
Assembly asm = null;
while (reader.Read())
{
if (reader.IsStartElement("AssemblyPart"))
{
reader.MoveToAttribute("Source");
reader.ReadAttributeValue();
if (reader.Value == assemblyName)
{
var assemblyStream = new StreamResourceInfo(e.Result, "application/binary");
var si = Application.GetResourceStream(assemblyStream, new Uri(reader.Value, UriKind.Relative));
AssemblyPart p = new AssemblyPart();
asm = p.Load(si.Stream);
break;
}
}
}
if (asm == null)
throw new InvalidOperationException("Could not find specified assembly.");
var o = asm.CreateInstance(m_typeName);
if (o == null)
throw new InvalidOperationException("Could not create instance of requested type.");
RaiseXapLoadedEvent(o);
}

if you know the uri of the resource file, like:
"/COMPONENTNAME;component/resourcepath.xaml",
you can simply add this resource dictionary to your application by writing codes like:
Application.Current.Resources.MergedDictionaries.Add("*resourceuri*");
the "Application.Current" always points to the runtime application instance (host application), no matter where it is used.

Related

loading ResourceDictionary from baml using Baml2006Reader

How do can I read through a baml stream that contains a ResourceDictionaory using the Baml2006Reader and without acually instantiating the the ResourceDictionary?
I can ready through regular baml that just contains a UserControl just fine and I can examine the XAML tree using Baml2006Reader.NodeType etc.
But once the reader hits a ResourceDictionary, Baml2006Reader.Member.Name is "DeferrableContent" and Baml2006Reader.Value contains a MemoryStream that can not be parsed by another instance of Baml2006Reader. I can't event instantiate the reader:
System.IO.EndOfStreamException occurred HResult=-2147024858
Message=Unable to read beyond the end of the stream. Source=mscorlib
StackTrace:
at System.IO.MemoryStream.InternalReadInt32()
at System.Windows.Baml2006.Baml2006Reader.Process_Header()
at WpfApplication10.AssemblyExtensions.Read(Stream stream, List`1 result) in d:\Documents\Visual Studio
2012\Projects\WpfApplication10\WpfApplication10\AssemblyExtensions.cs:line
84 InnerException:
It seems that whenever the Baml2006Reader encounters an element where Baml2006Reader.Member.Name is "DeferrableContent" it is followed by another node where BamlReader.Value is a MemoryStream. It seems that this stream only contains a baml fragment and does not have a header (that's why System.Windows.Baml2006.Baml2006Reader.Process_Header() fails.)
So we need to tell the baml reader to read a baml fragment. This can be done be giving the reader an instance of System.Windows.Baml2006.Baml2006ReaderSettings where the IsBamlFragment property istrue.
Unfortunately both the Baml2006ReaderSettings class and the appropriate constructor of Baml2006Reader are internal. So we need to resort to reflection:
private static string PresentationFrameworkAssemblyName = "PresentationFramework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35";
private static Baml2006Reader CreateBamlFragmentReader(MemoryStream substream, XamlSchemaContext schemaContext)
{
var bamlSettingsType =
Type.GetType(
"System.Windows.Baml2006.Baml2006ReaderSettings, " + PresentationFrameworkAssemblyName);
var settingsCtor =
bamlSettingsType.GetConstructor(Type.EmptyTypes);
var bamlSettings = settingsCtor.Invoke(null);
var isBamlFragmentProp = bamlSettingsType.GetProperty("IsBamlFragment",
BindingFlags.NonPublic |
BindingFlags.Instance);
isBamlFragmentProp.SetValue(bamlSettings, true, null);
var ctor = typeof (Baml2006Reader).GetConstructor(
BindingFlags.Instance | BindingFlags.NonPublic,
null,
new[]
{
typeof (Stream),
Type.GetType(
"System.Windows.Baml2006.Baml2006SchemaContext, " + PresentationFrameworkAssemblyName),
bamlSettingsType
},
null);
return (Baml2006Reader)ctor.Invoke(new[] { substream, schemaContext, bamlSettings });
}
usage:
var substream = reader.Value as MemoryStream;
if (substream != null)
{
using (var subReader = CreateBamlFragmentReader(substream, reader.SchemaContext))
{
// continue reading with subReader
}
}
I know this is rather fragile code and very hackish, but what the heck - it works (for me, currently)!

How can I use encrypted xml file as application resources for xaml data binding?

I want to use encrypted xml file as application resource for easy xaml data binding. Xml file are encrypted in different application. I can use unencrypted xml for data binding. I cant use the same method for encrypted xml because the file is encrypted when it is loaded. I have to decrypt it first before it can be use. Problem is, where do I put decryption algorithm?
Here how i create the encrypted files(code for decrypt and verifying decrypted data are omitted)
RijndaelManaged algorithm = null;
algorithm = new RijndaelManaged();
string passwordBytes = "password"; //password here
byte[] saltBytes = Encoding.UTF8.GetBytes("salt"); // salt here (another string)
var p = new Rfc2898DeriveBytes(passwordBytes, saltBytes);
algorithm.IV = p.GetBytes(algorithm.BlockSize / 8);
algorithm.Key = p.GetBytes(algorithm.KeySize / 8);
var xmlDoc = new XmlDocument();
xmlDoc.PreserveWhitespace = true;
xmlDoc.Load("Bands.xml");
// Encrypt the "Bands" element.
Encrypt(xmlDoc, "Bands", algorithm);
xmlDoc.Save("encryptedBands.xml");
To decrypt, i just call these(assuming xmlDoc and algorithm are same as above.
Decrypt(xmlDoc, algorithm);
Here are encrypt and decrypt algorithm based on msdn(nothing special).
public static void Encrypt(XmlDocument Doc, string ElementName, SymmetricAlgorithm Key)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullException("Doc");
if (ElementName == null)
throw new ArgumentNullException("ElementToEncrypt");
if (Key == null)
throw new ArgumentNullException("Alg");
var elementToEncrypt = Doc.GetElementsByTagName(ElementName)[0] as XmlElement;
// Throw an XmlException if the element was not found.
if (elementToEncrypt == null)
{
throw new XmlException("The specified element was not found");
}
var eXml = new EncryptedXml();
byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, Key, false);
var edElement = new EncryptedData();
edElement.Type = EncryptedXml.XmlEncElementUrl;
string encryptionMethod = null;
if (Key is TripleDES)
{
encryptionMethod = EncryptedXml.XmlEncTripleDESUrl;
}
else if (Key is DES)
{
encryptionMethod = EncryptedXml.XmlEncDESUrl;
}
if (Key is Rijndael)
{
switch (Key.KeySize)
{
case 128:
encryptionMethod = EncryptedXml.XmlEncAES128Url;
break;
case 192:
encryptionMethod = EncryptedXml.XmlEncAES192Url;
break;
case 256:
encryptionMethod = EncryptedXml.XmlEncAES256Url;
break;
}
}
else
{
// Throw an exception if the transform is not in the previous categories
throw new CryptographicException("The specified algorithm is not supported for XML Encryption.");
}
edElement.EncryptionMethod = new EncryptionMethod(encryptionMethod);
// Add the encrypted element data to the
// EncryptedData object.
edElement.CipherData.CipherValue = encryptedElement;
EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);
}
public static void Decrypt(XmlDocument Doc, SymmetricAlgorithm Alg)
{
// Check the arguments.
if (Doc == null)
throw new ArgumentNullException("Doc");
if (Alg == null)
throw new ArgumentNullException("Alg");
// Find the EncryptedData element in the XmlDocument.
var encryptedElement = Doc.GetElementsByTagName("EncryptedData")[0] as XmlElement;
// If the EncryptedData element was not found, throw an exception.
if (encryptedElement == null)
{
throw new XmlException("The EncryptedData element was not found.");
}
// Create an EncryptedData object and populate it.
var edElement = new EncryptedData();
edElement.LoadXml(encryptedElement);
// Create a new EncryptedXml object.
var exml = new EncryptedXml();
// Decrypt the element using the symmetric key.
byte[] rgbOutput = exml.DecryptData(edElement, Alg);
// Replace the encryptedData element with the plaintext XML element.
exml.ReplaceData(encryptedElement, rgbOutput);
}
I want to use the encrypted xml data as data source for easy data binding in xaml. I declare xml data at application level for application wide access. Here's how I declared it in App.xaml.
<Application.Resources>
<ResourceDictionary>
<XmlDataProvider x:Key="encryptedBandsDataSource" Source="/RemoteConfigurator;component/encryptedBands.xml" d:IsDataSource="True"/>
</ResourceDictionary>
</Application.Resources>
Problem is, I need to decrypt the xml file before App.xaml is even loaded. Is it possible to do that. How do I do that. Where do I decrypt the xml file?
In short, how can I use encrypted xml file as application resources?
Two options, a quick one and a clean one...
Option 1 (quick): Decrypt file before loading the app
If you decrypt your file, before base.OnStartup(e) is called in app.xaml.cs, it should work...
using System.Windows;
namespace MainApplication
{
/// <summary>
/// Interaction logic for App.xaml
/// </summary>
public partial class App
{
protected override void OnStartup(StartupEventArgs e)
{
DecryptXml();
base.OnStartup(e);
MainBootstrapper bootstrapper = new MainBootstrapper();
bootstrapper.Run();
}
}
}
Option 2 (clean): Custom XmlDataProvider to handle encrypted XML files
Another option is to write a custom XmlDataProvider, say EncryptedXmlDataProvider, which holds an EncryptedSource property and some other properties to specify how to decrypt the file. EncryptedXmlDataProvider can decrypt the file, when EncryptedSource property is set. This way, the Data is blendable and you have a reusable type. A bit more work but much cleaner than the solution proposed above.

RestSharp - Download / Use image in WPF/Silverlight

I'm trying to use RestSharp to download an image from a WCF/Rest service. The result should be saved in a file and displayed in a Image control an a WPF/SL page.
private void GetImage()
{
RestClient _Client = new RestClient(BASE_URI);
RestRequest request = new RestRequest("/api/img/{FileName}");
request.AddParameter("FileName", "dummy.jpg", ParameterType.UrlSegment);
_Client.ExecuteAsync<MemoryStream>(
request,
Response =>
{
if (Response != null)
{
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = Response.Data;
String fn = String.Format(#"c:\temp\{0}.jpg", Guid.NewGuid().ToString());
System.IO.File.WriteAllBytes(fn,Response.Data.ToArray());
bitmapImage.EndInit();
img.Source = bitmapImage;
}
});
}
When I look in fiddler the image got downloaded correctly BUT no image is saved and nothing is displayd. There is no exception thown. ANy suggestions ?
UPDATED
A part of the problem turns out that RestSharp is not returning the expected memorystream. Moving to another methed and accessing the raw data in byte[] format solves part of the problem, saving the picutere to disk.
private void GetImage()
{
RestClient _Client = new RestClient(BASE_URI);
RestRequest request = new RestRequest("/api/img/{FileName}");
request.AddParameter("FileName", "dummy.jpg", ParameterType.UrlSegment);
_Client.ExecuteAsync(
request,
Response =>
{
if (Response != null)
{
byte[] imageBytes = Response.RawBytes;
var bitmapImage = new BitmapImage();
bitmapImage.BeginInit();
bitmapImage.StreamSource = new MemoryStream(imageBytes);
bitmapImage.CreateOptions = BitmapCreateOptions.None;
bitmapImage.CacheOption = BitmapCacheOption.Default;
bitmapImage.EndInit();
JpegBitmapEncoder encoder = new JpegBitmapEncoder();
Guid photoID = System.Guid.NewGuid();
String photolocation = String.Format(#"c:\temp\{0}.jpg", Guid.NewGuid().ToString());
encoder.Frames.Add(BitmapFrame.Create(bitmapImage));
using (var filestream = new FileStream(photolocation, FileMode.Create))
encoder.Save(filestream);
this.Dispatcher.Invoke((Action)(() => { img.Source = bitmapImage; }));
;
}
});
}
Although calling this.dispatcher.Invoke I still get the error : The calling thread cannot acces this object because a different thread owns it.
As the BitmapImage is created in another thread than the UI thread, you also have to call Freeze to make it accessible in the UI thread.
Although not strictly necessary here, it is good practise to always dispose of any IDisposable objects, including MemoryStream. Therefore you will also have to set the BitmapImage.CacheOption property to OnLoad.
using (var memoryStream = new MemoryStream(imageBytes))
{
bitmapImage.BeginInit();
bitmapImage.CacheOption = BitmapCacheOption.OnLoad;
bitmapImage.StreamSource = memoryStream;
bitmapImage.EndInit();
bitmapImage.Freeze();
}
The frozen BitmapImage is accessible in the UI thread:
Dispatcher.Invoke((Action)(() => img.Source = bitmapImage));
Are you checking for exceptions using the debugger? If an exception is thrown on a background task, it won't be rethrown on the caller code unless you access Task.Result or use the await operator.
My guess is that you don't have access to the location of C: you are writing to. That block of code seems unnecessary anyway though, you should be able to directly set the source of the image to the stream you have without writing it to disk. Try commenting the writing to drive piece of code out and see if that solves the issue.

DocumentViewer to RichTextBox Binding Error

I have an application with RichTextBox and DocumentViewer (placed in a TabControl), and I want to make something like "hot preview". I've binded DocumentViewer.Document property to RichTextBox.Document
Binding:
<DocumentViewer Document="{Binding Document, Converter={StaticResource FlowDocumentToPaginatorConverter}, ElementName=mainRTB, Mode=OneWay}" />
And this is Converter code:
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
FlowDocument d = value as FlowDocument;
DocumentPaginator pagin = ((IDocumentPaginatorSource)d).DocumentPaginator;
FixedDocumentSequence result = null;
Size s = new Size(793.700787402, 1122.519685039);
pagin.PageSize = s;
using (MemoryStream ms = new MemoryStream())
{
TextRange tr = new TextRange(d.ContentStart, d.ContentEnd);
tr.Save(ms, DataFormats.XamlPackage);
Package p = Package.Open(ms, FileMode.Create, FileAccess.ReadWrite);
Uri uri = new Uri(#"memorystream://doc.xps");
PackageStore.AddPackage(uri, p);
XpsDocument xpsDoc = new XpsDocument(p);
xpsDoc.Uri = uri;
XpsDocument.CreateXpsDocumentWriter(xpsDoc).Write(pagin);
result = xpsDoc.GetFixedDocumentSequence();
}
return result;
}
When I start this application everything is ok until I switch to tab with DocumentViewer. Application crushes and I get such Exception:
Cannot perform a read operation in write-only mode.
What I am doing wrong? Is it possible to make this binding?
The error message is indeed confusing and reason not immediately obvious. Basically you are closing the MemoryStream that holds XpsDocument too early and when the DocumentViewer attempts to read the document it cannot as it is write-only mode (because the stream was closed).
The solution is to not immediately close the MemoryStream until after you have finished viewing the document. To achieve this I wrote an XpsDocumentConverter that returns XpsReference.
Also, as you never been able to convert and display a single XpsDocument you won't have yet encountered the next issue of having multiple packages in the PackageStore with the same Uri. I have taken care of this in my implementation below.
public static XpsDocumentReference CreateXpsDocument(FlowDocument document)
{
// Do not close the memory stream as it still being used, it will be closed
// later when the XpsDocumentReference is Disposed.
MemoryStream ms = new MemoryStream();
// We store the package in the PackageStore
Uri uri = new Uri(String.Format("pack://temp_{0}.xps/", Guid.NewGuid().ToString("N")));
Package pkg = Package.Open(ms, FileMode.Create, FileAccess.ReadWrite);
PackageStore.AddPackage(uri, pkg);
XpsDocument xpsDocument = new XpsDocument(pkg, CompressionOption.Normal, uri.AbsoluteUri);
// Need to force render the FlowDocument before pagination.
// HACK: This is done by *briefly* showing the document.
DocumentHelper.ForceRenderFlowDocument(document);
XpsSerializationManager rsm = new XpsSerializationManager(new XpsPackagingPolicy(xpsDocument), false);
DocumentPaginator paginator = new FixedDocumentPaginator(document, A4PageDefinition.Default);
rsm.SaveAsXaml(paginator);
return new XpsDocumentReference(ms, xpsDocument);
}
public class XpsDocumentReference : IDisposable
{
private MemoryStream MemoryStream;
public XpsDocument XpsDocument { get; private set; }
public FixedDocument FixedDocument { get; private set; }
public XpsDocumentReference(MemoryStream ms, XpsDocument xpsDocument)
{
MemoryStream = ms;
XpsDocument = xpsDocument;
DocumentReference reference = xpsDocument.GetFixedDocumentSequence().References.FirstOrDefault();
if (reference != null)
FixedDocument = reference.GetDocument(false);
}
public void Dispose()
{
Package pkg = PackageStore.GetPackage(XpsDocument.Uri);
if (pkg != null)
{
pkg.Close();
PackageStore.RemovePackage(XpsDocument.Uri);
}
if (MemoryStream != null)
{
MemoryStream.Dispose();
MemoryStream = null;
}
}
}
XpsReference implements IDisposable so remember to call Dispose() on it.
Also, once you resolve the above error the next problem you are likely to encounter will be content not rendering as you would expect. This is caused by the fact you need to clone FlowDocument and it has not undergone a full measure and arrange layout pass. Read
Printing BlockUIContainer to XpsDocument/FixedDocument on how to solve this.

How can I write a folder of WPF image resources to disk?

I have a folder in my WPF app "Images" that has several .png files with their Build Action set to Resource. These are built into my binary since I can reference them in XAML.
I would like to write these to disk in the temp folder. How do I do this?
I have found several answers referring to Embedded Resources, but not just plain resources.
Answer!
public static void ExtractFileFromResources(String filename, String location)
{
StreamResourceInfo sri = System.Windows.Application.GetResourceStream(
new Uri("pack://application:,,,/Images/" + filename));
Stream resFilestream = sri.Stream;
if (resFilestream != null)
{
BinaryReader br = new BinaryReader(resFilestream);
FileStream fs = new FileStream(location, FileMode.Create);
BinaryWriter bw = new BinaryWriter(fs);
byte[] ba = new byte[resFilestream.Length];
resFilestream.Read(ba, 0, ba.Length);
bw.Write(ba);
br.Close();
bw.Close();
resFilestream.Close();
}
}

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