Develop Reference

How to display the skype user photo from HTTP Response using UCWA API?

I am working on Universal Windows Applications, in my current project I used Unified Communications Web API (UCWA) to display the skype user status it's working fine but when I am trying to display the skype user photo at that time I got stuck.
I followed below link to display the photo
https://msdn.microsoft.com/en-us/skype/ucwa/getmyphoto
I got response code of 200 OK for my GET request but I don't know how to display the image from my response.
Please tell me how to resolve it.
-Pradeep

I got Result, After getting HTTP Response then I am converting those response content to stream type by using this below line.
var presenceJsonStr = await httpResponseMessage.Content.ReadAsStreamAsync();
This is the code to display the image
var photo = await AuthenticationHelper.Photo();
// Create a .NET memory stream.
var memStream = new MemoryStream();
// Convert the stream to the memory stream, because a memory stream supports seeking.
await photo.CopyToAsync(memStream);
// Set the start position.
memStream.Position = 0;
// Create a new bitmap image.
var bitmap = new BitmapImage();
// Set the bitmap source to the stream, which is converted to a IRandomAccessStream.
bitmap.SetSource(memStream.AsRandomAccessStream());
// Set the image control source to the bitmap.
imagePreivew.ImageSource = bitmap;

Assuming you put an Accept header specifying an image type, you should be able to look at the Content-Length header to determine if the user has an image set on the server. If the length is zero you should consider providing a default image to be displayed. If not, I would suggest taking a look at Convert a Bitmapimage into a Byte Array and Vice Versa in UWP Platform as you should treat the response body as a byte array with its length defined by the Content-Length header.
If for some reason no Accept header was provided, the response body is not an image/* type, and looks like a string then you might be dealing with a Base64 encoded image. This case should be much less likely to deal with, but if you need advice I would suggest looking at Reading and Writing Base64 in the Windows Runtime.

You can directly use the URL generated for the user photo resource. Just set the URL of the image as the source of the Image container. You application would load it automatically.

some special character is replace by '?' while generating pdf from html

I am trying to generate pdf from html file using itextsharp library, but I have one issue in that when I convert html into pdf, some special character of html file is replace by '?' sign. (ex €)
here is my code :
var elements = XMLWorkerHelper.ParseToElementList(html, null);
foreach (var element in elements)
{
document.Add(element);
}
XMLWorkerHelper is a class of itextsharp library.
I just want that my pdf is generate same as my html file.

If you use XMLWorkerHelper.ParseToElementList(String, String) (which you are) then iTextSharp is going to ask the .Net runtime to figure out the contents of the file by calling System.Text.Encoding.Default.GetBytes().
Per the docs, System.Text.Encoding.Default
Gets an encoding for the operating system's current ANSI code page
And further (emphasis mine):
Different computers can use different encodings as the default, and the default encoding can even change on a single computer. Therefore, data streamed from one computer to another or even retrieved at different times on the same computer might be translated incorrectly. In addition, the encoding returned by the Default property uses best-fit fallback to map unsupported characters to characters supported by the code page. For these two reasons, using the default encoding is generally not recommended. To ensure that encoded bytes are decoded properly, you should use a Unicode encoding, such as UTF8Encoding or UnicodeEncoding, with a preamble. Another option is to use a higher-level protocol to ensure that the same format is used for encoding and decoding.
So from the above you'll see that in the absence of any information in the file about how the raw bytes are intended to be interpreted, .Net will just use the local code page to interpret them. What's really fun is if you move your code 100% exactly as-is to another machine you might get different results because that machine might have a different code page set.
The best solution is to avoid code pages completely. To do this, just save the file as Unicode compatible format such as UTF8 and include a BOM to explicitly declare your intentions. The BOM is optional (and frowned upon by some people) but it is also the most explicit way in the absence of other information (such as HTTP headers or post-it notes).
The second option is to just re-implement XMLWorkerHelper.ParseToElementList() with your appropriate encoding. SourceForge is apparently down right now so here's the body of that method:
/**
* Parses an HTML string and a string containing CSS into a list of Element objects.
* The FontProvider will be obtained from iText's FontFactory object.
*
* #param html a String containing an XHTML snippet
* #param css a String containing CSS
* #return an ElementList instance
*/
public static ElementList ParseToElementList(String html, String css) {
// CSS
ICSSResolver cssResolver = new StyleAttrCSSResolver();
if (css != null) {
ICssFile cssFile = XMLWorkerHelper.GetCSS(new MemoryStream(Encoding.Default.GetBytes(css)));
cssResolver.AddCss(cssFile);
}
// HTML
CssAppliers cssAppliers = new CssAppliersImpl(FontFactory.FontImp);
HtmlPipelineContext htmlContext = new HtmlPipelineContext(cssAppliers);
htmlContext.SetTagFactory(Tags.GetHtmlTagProcessorFactory());
htmlContext.AutoBookmark(false);
// Pipelines
ElementList elements = new ElementList();
ElementHandlerPipeline end = new ElementHandlerPipeline(elements, null);
HtmlPipeline htmlPipeline = new HtmlPipeline(htmlContext, end);
CssResolverPipeline cssPipeline = new CssResolverPipeline(cssResolver, htmlPipeline);
// XML Worker
XMLWorker worker = new XMLWorker(cssPipeline, true);
XMLParser p = new XMLParser(worker);
p.Parse(new MemoryStream(Encoding.Default.GetBytes(html)));
return elements;
}
The second to last line of code that starts p.Parse is what you'd want to change. Since we don't know what the bytes of your file are (and neither does your computer, apparently) we can't tell you what to switch the encoder over to.
Just to wrap up, this actually isn't an iTextSharp problem at all, this is actually the default behavior of the .Net runtime. iTextSharp is just using system default in the absence of information.

p.parse(new StringReader(html));
this worked for me

Using FileReader.readAsDataUrl to upload image to Web Api service

I am trying to use the FileReader to obtain the base-64 representation of an image and submit that to a .net WebApi service for image uploading.
My problem is that the contents of fileReader.result are not valid as a base-64 encoded image, at least according to .net.
I am just using a very simple method, and testing with fiddler to post to the service. If I post the complete result string from filereader.result, I get an error "Invalid length for a Base-64 char array or string" when I try and read the string using FromBase64String.
public void Post([FromBody]string imgString)
{
var myString = imgString.Split(new char[]{','});
byte[] bytes = Convert.FromBase64String(myString[1]);
using (MemoryStream ms = new MemoryStream(bytes))
{
Image image = Image.FromStream(ms);
image.Save("myBlargyImage.jpg");
}
}
Is cut+paste into fiddler doing something to the string that I need to account for here, or is there something else I am not doing correctly? This seems like it should be straightforward: Encode the image as a string, send the string, decode the string, save the image.
For example, using filereader to display a preview of the image on the client, I get the following in filereader.result:
src="data:image/jpeg;base64,/9j/4AAQSkZJRgABAgEAyADIAAD/...oBUA00AqYL/AMCg3//Z"
I have tried both sending the entire string ("data...Z"), and just the Base64 string. Currently, I am splitting the string server side to get the Base64 string. Doing this, I always get the invalid length error.
Alternatively, I have tried sending just the base64 string. Not knowing if the leading / was actually part of the string or not, I deleted it in the post body. Doing THIS, I can actually read the value into a byte array, but then I get an error using Image.FromStream that the array is not a valid image.
So, either I get an error that the entire string as provided by filereader is an invalid length, or, I hack it up and get an error that even if it is a valid length, it is not a valid image (when reading the bytearray). That is what makes me wonder if there is some issue of translation or formatting between the filereader.read, dev tools in chrome, then cutting and pasting into fiddler.
UPDATE:
I tried a more realistic implementation by just taking the filereader.result and putting it in a $.post() call, and it works as expected.
It appears I was right, that I, or notepad++, or fiddler, are doing something to the data when I touch it to cut and paste filereader.result into a service call.
If someone knows exactly what that might be, or how one can verify they are sending a valid base-64 encoding of an image to a service, it might help others who are attempting the same thing in the future.
Again, if in the browser filereader.result yielded 'data:image/jpeg;base64,somestring', I was simply copying that string from the developer tools panel, creating a fiddler call and in the request body including the copied string: "=data:image/jpeg;base64,somestring". Somehow, the base-64 'somestring' was getting munched in the cut+paste.
function readURL(input) {
if (input.files && input.files[0]) {
reader = new FileReader();
reader.onload = function (e) {
$('#imgPreview').attr('src', e.target.result);
$.post('/api/testy/t/4',
{'':e.target.result}
);
};
reader.readAsDataURL(input.files[0]);
reader.onloadend = function (e) {
console.log(e.target.result);
};
}
}
$("#imgUpload").change(function () {
readURL(this);
});

Don't forget to remove the 'noise' from a dataUrl,
For example in
data:image/png;base64,B64_DATA_HERE
you have to remove the data:image/png;base64, part before, so you process only the base 64 portion.
With js, it would be
var b64 = dataUrl.split("base64,")[1];
Hope this helps. Cheers

A data uri is not a base64 encode string, it may contain a base64 encoded string at the end of it. In this case it does, so you need to only send the base64 encoded string part.
var imagestr = datauri.split(',')[1];
sendToWebService(imagestr);

Make sure fiddler is not truncating the Base 64 String

C# decoding "â„¢" to "TM"

on a web page there is following string
"Qualcomm Snapdragon™ S4"
when i get this string in my .net code the string convert to "Qualcomm Snapdragonâ„¢ S4"
the character "TM" change to â„¢
how can i decode "â„¢" back to "TM"
Update
follwoing is the code for downloaded string using webproxy
wc is webproxy
wc.Headers.Add("Accept-Charset", "ISO-8859-1,utf-8");
string html = Server.HtmlEncode(wc.DownloadString(url));

You should read the webpage in its proper encoding in the first place. In this case it seems you are reading with Encoding.Default (i.e. probably CP1252) and the page is really in UTF-8. This should be apparent either by reading the Content-Type header of the response or by looking for a <meta http-equiv="Content-Type" content='text/html; charset=utf-8'> in the content.
If you still need to do this after the fact, then use
var bytes = Encoding.Default.GetBytes(myString);
var correctString = Encoding.UTF8.GetString(bytes);
In any case you would need to know the exact encodings that were used on the page and for reading the malformed string in the first place. Furthermore I'd generally advise explicitly against using Encoding.Default because its value isn't fixed. It's just the legacy encoding on a Windows system for use in non-Unicode applications and also gets used as the default non-Unicode text file encoding. It should have no place whatsoever in handling external resources.

How do I get a C# WebBrowser control to show jpeg files (raw)?

Does anyone know in .Net 2.0 - .Net 3.5 how to load a jpeg into a System.Windows.Forms.WebControl as a byte-array and with the right mimetypes set so it will show?
Something like:
webBrowser1.DocumentStream = new MemoryStream(File.ReadAllBytes("mypic.jpg"));
webBrowser1.DocumentType = "application/jpeg";
The webBrowser1.DocumentType seems to be read only, so I do not know how to do this. In general I want to be able to load any kind of filesource with a mimetype defined into the browser to show it.
Solutions with writing temp files are not good ones. Currently I have solved it with having a little local webserver socket listener that delivers the jpeg I ask for with the right mimetype.
UPDATE: Since someone deleted a answer-my-own question where I had info that others could use, I will add it as an update instead. (to those who delete that way, please update the questions with the important info).
Sample solution in C# here that works perfectly: http://www.codeproject.com/KB/aspnet/AspxProtocol.aspx

You have to implement an async pluggable protocol, e.g. IClassFactory, IInternetProtocol... Then you use CoInternetGetSession to register your protocol. When IE calls your implementation, you can serve your image data from memory/provide mime type.
It's a bit tedious, but doable. Look at IInternetProtocol and pluggable protocols documentation on MSDN.

You cannot do it. You cannot stuff images into Microsoft's web-browser control.
The limitation comes from the IWebBrowser control itself, which .NET wraps up.

If you want a total hack, try having your stream be the HTML file that only shows your picture. You lose your image byte stream and will have to write the image to disk.

I do not know whether the WebBrowser .NET control supports this, but RFC2397 defines how to use inline images. Using this and a XHTML snippet created on-the-fly, you could possibly assign the image without the need to write it to a file.
Image someImage = Image.FromFile("mypic.jpg");
// Firstly, get the image as a base64 encoded string
ImageConverter imageConverter = new ImageConverter();
byte[] buffer = (byte[])imageConverter.ConvertTo(someImage, typeof(byte[]));
string base64 = Convert.ToBase64String(buffer, Base64FormattingOptions.InsertLineBreaks);
// Then, dynamically create some XHTML for this (as this is just a sample, minimalistic XHTML :D)
string html = "<img src=\"data:image/" . someImage.RawFormat.ToString() . ";base64, " . $base64 . "\">";
// And put it into some stream
using (StreamWriter streamWriter = new StreamWriter(new MemoryStream()))
{
streamWriter.Write(html);
streamWriter.Flush();
webBrowser.DocumentStream = streamWriter.BaseStream;
webBrowser.DocumentType = "text/html";
}
No idea whether this solution is elegant, but I guess it is not. My excuse for not being sure is that it is late at night. :)
References:
RFC2397
Image to base64 encoded string

IE only support 32KB for inline images in base64 encoding, so not a good solution.

Try the res: protocol.
I haven't tried it with a .net dll but this post says it should work. Even if it does require a C++ dll it's much simpler to use as far as coding goes.
I've created a post that show you how here that shows you how to create the resource script and use the res: protocol correctly.