Create attachment from the stream of the data - c#

I am trying to create SendGrid email attachment on-the-fly in C# on Azure. How can I correct the following code where someString is a variable holding the attachment xml content as directly retrieved from the DB?
using (var attachmentFileStream = new FileStream(#someString, FileMode.Open))
{
message.AddAttachment(attachmentFileStream, "someattachmentname.xml");
}
It does not seem to like it. I am getting the following errors:
Illegal characters in path. Access to the path
'D:\Windows\system32-1' is denied.

OK... i think I figured it out. When I pass the stream type into the method I need to strip the "using (var attachmentFileStream..." wrap and pass it directly into the myMessage.AddAttachment i.e.:
// convert to Stream type not MemoryStream!
byte[] byteArray = Encoding.UTF8.GetBytes(someString);
Stream theStream = new MemoryStream(byteArray);
myMessage.AddAttachment(theStream, "someattachmentname.xml");

Related

C# Binary string to Bytearray without conversion

I call an API to get a PDF file. The API returns it as a string with binary data.
Now I need to save it to a file without any conversion of the data.
How can I do this in C#?
I have been trying
string file = await service.GetDocumentsAsync(document.FileId); // Gets the filedata
byte[] byteArray = file.Select (c => (byte)c).ToArray ();
using (var stream = new FileStream($"c:\\temp\\{document.Id}.pdf", FileMode.Create))
{
stream.Write (byteArray,0,file.Length);
stream.Close ();
}
I do get the PDF, but it only has blank pages.
The beginning of the string when i look at it in the Debugger:
As suggested we had to change what the API returned. We use RestSharp and had to use Response.RawByte iso. Response.

Exception: Error getting value from 'Position' on 'Amazon.Runtime.Internal.Util.MD5Stream'

I am facing this exception
Error getting value from 'Position' on 'Amazon.Runtime.Internal.Util.MD5Stream'.
when trying to read file from aws s3 bucket.
Here is my c# code
try
{
var s3ObjectPath = $"users/{email.Id}/emailattachments/{item.AttachedFileName}";
var ifExists = await this.Exists(s3ObjectPath);
if (ifExists)
{
Stream attachment = await s3Client.GetObjectStreamAsync(attachmentS3BucketName, s3ObjectPath, dicData);
Attachment att = new Attachment(attachment, item.AttachedFileName);
attachments.Add(att);
}
}
catch (AmazonS3Exception ex)
{
}
However this is working sometimes. I searched everywhere but didn't find solution.
Thanks in advance!!
This is due to an issue with how Streams work. When you open a Stream you are not actually getting the content of the file, rather you are opening a connection enabling you to access the data.
The error you got is returned when your code is trying to access the stream but doesn't have the ability to do so (a connection being lost / no appropriate credentials in the code accessing the stream or any other reason).
The solution is either to solve the underlaying issue and make sure your code still as access to the Stream or to just read from the stream and return a string rather than a stream
The code addition would look something like this:
...
Stream attachment = await s3Client.GetObjectStreamAsync(attachmentS3BucketName, s3ObjectPath, dicData);
StreamReader reader = new StreamReader(attachment);
string attachmentText = reader.ReadToEnd();
Attachment att = new Attachment(attachmentText, item.AttachedFileName);
attachments.Add(att);

Getting Json Output from Byte Array

I just started a new project on WCF and to be honest I'm very new at this with limited knowledge.
So what I'm trying to do is open a file that is stored in my computer (e.g. word, pdf, etc.) and display the contents in the webpage in JSon format. I converted the file in a byte array and tried to display the Stream. When I did that it asked me to open the file or save it. I don't want that - I just want the contents of the file to be displayed on my local host when i call the method.
Here's what I have:
public string GetRawFile()
{
string file = #"C:\.....\TestFile.pdf";
byte[] rawFile = File.ReadAllBytes(file);
//Stream stream = new MemoryStream(rawFile);
//DataContractJsonSerializer obj = newDataContractJsonSerializer(typeof(string));
//string result = obj.ReadObject(stream).ToString();
//Deserializing
MemoryStream stream = new MemoryStream();
BinaryFormatter binForm = new BinaryFormatter();
stream.Write(rawFile, 0, rawFile.Length);
stream.Seek(0, SeekOrigin.Begin);
Object obj = (Object) binForm.Deserialize(stream);
System.Web.Script.Serialization.JavaScriptSerializer xyz = new System.Web.Script.Serialization.JavaScriptSerializer();
string ejson = xyz.Serialize(obj);
WebOperationContext.Current.OutgoingRequest.ContentType = "text/json";
return ejson;
}
I'm trying to return a string and it's not working, but when I return just the stream it's popping up the "openwith" message.
Also should I use the GET or POST on my datacontract. I'm using REST in C#.
I'm assuming that your file actually contains json. If that is the case just do this;
string file = File.ReadAllText("C:\path\to\file.extension");
You're making the problem a lot more complicated than it needs to be. Just read the file and return it's data as a string. I think you want to use GET for the http method. Generally speaking, you all use post if you're adding new content. If for example the users request would cause the application to write some data to a file or data base then you would typically use POST for the http method. If they're just requesting data, you almost always use GET.

why wont XML read from string? (but will from .txt of same data)

this is the code in question:
using (var file = MemoryMappedFile.OpenExisting("AIDA64_SensorValues"))
{
using (var readerz = file.CreateViewAccessor(0, 0))
{
var bytes = new byte[567];
var encoding = Encoding.ASCII;
readerz.ReadArray<byte>(0, bytes, 0, bytes.Length);
File.WriteAllText("C:\\myFile.txt", encoding.GetString(bytes));
var readerSettings = new XmlReaderSettings { ConformanceLevel = ConformanceLevel.Fragment };
using (var reader = XmlReader.Create("C:\\myFile.txt", readerSettings))
{
This is what myfile.txt looks like:
<sys><id>SCPUCLK</id><label>CPU Clock</label><value>1598</value></sys><sys><id>SCPUFSB</id><label>CPU FSB</label><value>266</value></sys><sys><id>SMEMSPEED</id><label>Memory Speed</label><value>DDR2-667</value></sys><sys><id>SFREEMEM</id><label>Free Memory</label><value>415</value></sys><sys><id>SGPU1CLK</id><label>GPU Clock</label><value>562</value></sys><sys><id>SFREELVMEM</id><label>Free Local Video Memory</label><value>229</value></sys><temp><id>TCPU</id><label>CPU</label><value>42</value></temp><temp><id>TGPU1</id><label>GPU</label><value>58</value></temp>
if i write the data to a txt file on the hard drive with:
File.WriteAllText("C:\\myFile.txt", encoding.GetString(bytes));
then read that same text file with the fragment XmlReader:
XmlReader.Create("C:\\myFile.txt");
it reads it just fine, the program runs and completes like it supposed to, but then if i directly read with the fragment XmlReader like:
XmlReader.Create(encoding.GetString(bytes));
I get exception when run " illegal characters in path" on the XmlReader.Create line.
ive tried writing it to a separate string first and reading that with xmlreader, and it wouldn't help to try to print it to CMD to see what it looks like because CMD wouldnt show the invalid characters im dealing with right?
but oh well i did Console.WriteLine(encoding.GetString(bytes)); and it precisely matched the txt file.
so somehow writing it to the text file is removing some "illegal characters"? what do you guys think?
XmlReader.Create(encoding.GetString(bytes));
XmlReader.Create() interprets your string as the URI where it should read a file from. Instead encapsulate your bytes in a StringReader:
StringReader sr = new StringReader(encoding.GetString(bytes));
XmlReader.Create(sr);
Here:
XmlReader.Create(encoding.GetString(bytes));
you are simply invoking the following method which takes a string representing a filename. However you are passing the actual XML string to it which obviously is an invalid filename.
If you want to load the reader from a buffer you could use a stream:
byte[] bytes = ... represents the XML bytes
using (var stream = new MemoryStream(bytes))
using (var reader = XmlReader.Create(stream))
{
...
}
The method XmlReader.Create() with a single string as argument needs a URI passed and not the XML document as string, please refer to the MSDN. It tries to open a file named "<..." which is an invalid URI. You can pass a Stream instead.
You are passing the xml content in the place where it is expecting a path, as evidenced by the error - illegal characters in path
Use an appropriate overload, and pass a stream - http://msdn.microsoft.com/en-us/library/system.xml.xmlreader.create.aspx

FileStream with querystring in filename?

I have a need to be able to open a file on disk but pass in parameters to that file via a querystring. It's a .SWF file, so I'm passing in the parameter necessary to get it to load correctly.
The code I'm using to do so is:
FileStream fs = new FileStream(#"C:\test\file.swf?key=value", FileMode.Open, FileAccess.Read);
I'm getting an error opening the file: "Invalid characters in path" because of the "?" in the filename. Is there any way to load a file from disk into a FileStream object using a querystring in the filename?
I think you can't do what you're trying to do. When you load a file from disk the querystring does not exist as a concept. It will only return the bytes contained in the SWF file.
The querystring matters at the execution level.
So I solved this problem by putting my two SWF files on a web server and using the following code. Not exactly production ready code, but it illustrates the concept.
private static FileStream GetFileStream()
{
string url = #"http://www.someurl.com/shell.swf?Filename=actualfile.swf";
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
WebResponse response = request.GetResponse();
byte[] result = null;
int byteCount = Convert.ToInt32(response.ContentLength);
using (BinaryReader reader = new BinaryReader(response.GetResponseStream()))
result = reader.ReadBytes(byteCount);
return new FileStream(result);
}

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