I'm having trouble deserializing my XML file from a MemoryStream. I have a generated MyXmlFile class and a MemoryStream containing an XML file which I want to deserialize into an object of type MyXmlFile.
public static class XmlSerializeObject
{
public static T FromStream<T>(Stream s)
{
var serializer = new XmlSerializer(typeof(T));
return (T) serializer.Deserialize(s);
}
}
I have a MemoryStream ms which contains an xml file. If I try to deserialize that stream into an object of type MyXmlFile I get an exception "There is an error in XML document (0,0)"
MyXmlFile test = XmlSerializeObject.FromStream<MyXmlFile>(ms);
However I verified that my MemoryStream is correct. If I first write my stream into a file on my disc and than read that file again it works fine.
FileStream outStream = File.OpenWrite("D:\\p.xml");
outStream.Write(((MemoryStream)ms).ToArray(), 0, ((MemoryStream)ms).ToArray().Length);
outStream.Flush();
outStream.Close();
MyXmlFile test= XmlSerializeObject.FromStream<MyXmlFile>(File.OpenRead("D:\\p.xml"));
I was not able to find a solution myself that is why I decided to post my question. Maybe someone had the same problem before and is able to help me out.
Thanks in advance. If anything is unclear please ask.
If you instantiated your memory stream prior to your call to deserialize (say, to load the XML into the memory stream in the first place) it may be that it's at the wrong index. Try
ms.Seek(0, SeekOrigin.Begin)
To go back to the beginning of the stream.
You must set position of MemoryStream to the 0.
((MemoryStream)ms).Position = 0;
MyXmlFile test = XmlSerializeObject.FromStream<MyXmlFile>(ms);
Related
I have one scenario with class like this.
Class Document
{
public string Name {get;set;}
public byte[] Contents {get;set;}
}
Now I am trying to implement the import export functionality where I keep the document in binary so the document will be in json file with other fields and the document will be something in this format.
UEsDBBQABgAIAAAAIQCitGbRsgEAALEHAAATAAgCW0NvbnRlbnRfVHlwZXNdLnhtbCCiBAIooAACAAAAAAA==
Now when I upload this file back, I get this file as a string and I get the same data but when I try to convert this in binary bytes[] the file become corrupt.
How can I achieve this ?
I use something like this to convert
var ss = sr.ReadToEnd();
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream);
writer.Write(ss);
writer.Flush();
stream.Position = 0;
var bytes = default(byte[]);
bytes = stream.ToArray();
This looks like base 64. Use:
System.Convert.ToBase64String(b)
https://msdn.microsoft.com/en-us/library/dhx0d524%28v=vs.110%29.aspx
And
System.Convert.FromBase64String(s)
https://msdn.microsoft.com/en-us/library/system.convert.frombase64string%28v=vs.110%29.aspx
You need to de-code it from base64, like this:
Assuming you've read the file into ss as a string.
var bytes = Convert.FromBase64String(ss);
There are several things going on here. You need to know the encoding for the default StreamWriter, if it is not specified it defaults to UTF-8 encoding. However, .NET strings are always either UNICODE or UTF-16.
MemoryStream from string - confusion about Encoding to use
I would suggest using System.Convert.ToBase64String(someByteArray) and its counterpart System.Convert.FromBase64String(someString) to handle this for you.
I have big big data in form of bytes around 5GB.
I need to store this data in a file ServerData.xml. This data should be first converted into string and then should be saved to file so that we can perform operation on the file.
I used below code to convert stream of bytes to string and then to save the same in a file.
private const string fileName = "ServerData.xml";
public void ProcessBuffer(byte[] receiveBuffer, int bytes)
{
if (!File.Exists(fileName))
{
using (File.Create(fileName)) { };
}
TextWriter tw = new StreamWriter(fileName, true);
tw.Write(Encoding.UTF8.GetString(receiveBuffer).TrimEnd((Char)0));
tw.Close();
}
Is it the right way ?
or please suggest better way so that there should not be any memory issue if any in future ?
The code in your question can only work if ProcessBuffer is always called with a UTF-8 encoded text that is broken on code point boundaries. That seems pretty unlikely to me, so I would expect that you encounter errors when decoding to text.
However, decoding to text and then writing, is rather pointless and indeed counter-productive. The bytes are already UTF-8 encoded. Write them directly to file as they arrive from the socket. Don't perform any processing of them. When you come to read the XML using XmlReader, the parser will read the encoding as UTF-8 from the document's XML declaration, and be able to decode the rest of the document. I am assuming that the document's XML declaration specifies UTF-8 but that seems highly likely. You should check.
You should get rid of the text writer which is no use to you for writing bytes. Write the bytes directly to a file stream. And try to avoid opening and closing the file repeatedly. That's very inefficient. Open and close the file exactly once.
Why do you need to convert it to a string?
using System.IO;
public static void WriteBytes(byte[] bytes, string filename)
{
using (FileStream fs = new FileStream(filename, FileMode.OpenOrCreate))
using (BinaryWriter writer = new BinaryWriter(fs, Encoding.UTF8))
{
writer.Write(bytes);
}
}
You can simply write these bytes to a file using FileStream:
public void ProcessBuffer(byte[] receivedBuffer, int bytes)
{
using (var fileStream = new FileStream(fileName, FileMode.Create)) // overwrites file
{
fileStream.Write(receivedBuffer, 0, bytes);
}
}
Update: You won't be able to work with such a big XML document if you don't have enough resources. I would suggest reformatting this file. For example, I would parse this XML and insert data into a SQL database. Then, you can easily operate with such amounts of data.
I would prefer that I write all bytes to file. And when reading, convert it to string and then convert to XML using XDocument, XElement etc. By writing bytes in file you will save space, and it is efficient,
Instead of using FileStream, I will prefer File.WriteAllBytes method.
private const string fileName = "ServerData.xml";
public void ProcessBuffer(byte[] receiveBuffer, int bytes)
{
File.WriteAllBytes(filename, bytes);
// And when reading
var bytes = File.ReadAllBytes(filename);
var binaryReader = new BinaryReader(new MemoryStream(bytes));
// Parse strings and make xml,
binaryReader.ReadString();
}
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.
I have a list of events and I save it in a binary file using this code
using (FileStream fs = new FileStream(fileName, FileMode.CreateNew))
{
using (BinaryWriter w = new BinaryWriter(fs))
{
foreach (MacroEvent macroEvent in events)
{
w.Write(macroEvent.TimeSinceLastEvent);
}
}
}
but I'm confused to how I read and get it back again in a list?
The following recipe is a good guide on how to implement ISerializable for an object you want to serialize and deserialize with a BinaryFormatter:
http://www.switchonthecode.com/tutorials/csharp-tutorial-serialize-objects-to-a-file
Here is the NET 4.0 documentation on BinaryFormatter:
http://msdn.microsoft.com/en-us/library/system.runtime.serialization.formatters.binary.binaryformatter.aspx
and ISerializable:
http://msdn.microsoft.com/en-us/library/system.runtime.serialization.iserializable.aspx
Sequential file access File using serialization
Add
Using system.Io
Using system.Runtime.Serialzation.Formatters.Binary
Using System.Runtime.Serialization
Using Macro Events
name space created fileform : macroform
//Object For serializing RecordSerializables in binary format
Private Binary formatter = new binaryFormatter();
Private file stream output; //stream for writing to a file
Use method Deserialize to read data
Cast result of Deserialize to type serializeable to type serializeable this cast is necessary ,because Deserialize returns a refrence of type object and need to access properties that belong to class serializable. If an error during deserialization is thrown
a serialization is thrown and the file stream is closed
Private BinaryFormatter eader = new BinaryFormatter();
Private File stream input; // stream for reading from file
How do I deserialize a binary file to a string?
This is my sample code so far:
public function serialize()
{
FileStream fs = new FileStream("test.txt", FileMode.Append);
BinaryFormatter formatter = new BinaryFormatter();
formatter.Serialize(fs, textBox1.Text);
fs.Flush();
fs.Close();
}
public function deserialize()
{
FileStream fs = File.Open(openFileDialog1.FileName, FileMode.Open);
BinaryFormatter formatter = new BinaryFormatter();
richTextBox1.Text = formatter.Deserialize(mystream) as string;
fs.Flush();
fs.Close();
}
When I start to debug the application, it only shows the first string of the stream. The rest of the stream did not show up. How should I fix this?
Just use
System.IO.File.WriteAllText(fileName, textBox1.Text);
and
textBox1.Text = System.IO.File.ReadAllText(fileName);
The right way to do this is to put all of the values that you want to serialize into a serializable structure and then serialize that structure. On the other end you deserialize that structure and then put the values where they need to go.
Note that the binary serializer produces binary, not text output. If you want human readable serialized data you can use the XmlSerializer instead.
Binary serialization serializes object graphs; it doesn't just write strings.
It wouldn't make sense to combine object graphs.
You should read and write the file directly using the File class.