How do I generate a stream from a string

Question

I need to write a unit test for a method that takes a stream which comes from a text file  I would like to do do something like this   Stream s   GenerateStreamFromString  a b  n c d

User · Answer

A good combination of String extensions   public static byte   GetBytes this string str        byte   bytes   new byte str Length   sizeof char        System Buffer BlockCopy str ToCharArray    0  bytes  0  bytes Length       return bytes     public static Stream ToStream this string str        Stream StringStream   new MemoryStream        StringStream Read str GetBytes    0  str Length       return StringStream

User · Answer

public static Stream GenerateStreamFromString string s        var stream   new MemoryStream        var writer   new StreamWriter stream       writer Write s       writer Flush        stream Position   0      return stream      Don t forget to use Using   using  var stream   GenerateStreamFromString  a b  n c d                 Do stuff to stream       About the StreamWriter not being disposed  StreamWriter is just a wrapper around the base stream  and doesn t use any resources that need to be disposed  The Dispose method will close the underlying Stream that StreamWriter is writing to  In this case that is the MemoryStream we want to return   In  NET 4 5 there is now an overload for StreamWriter that keeps the underlying stream open after the writer is disposed of  but this code does the same thing and works with other versions of  NET too   See Is there any way to close a StreamWriter without closing its BaseStream

User · Answer

Here you go   private Stream GenerateStreamFromString String p        Byte   bytes   UTF8Encoding GetBytes p       MemoryStream strm   new MemoryStream        strm Write bytes  0  bytes Length       return strm

User · Answer

public Stream GenerateStreamFromString string s        return new MemoryStream Encoding UTF8 GetBytes s

User · Answer

I think you can benefit from using a MemoryStream  You can fill it with the string bytes that you obtain by using the GetBytes method of the Encoding class

User · Answer

If you need to change the encoding I vote for  ShaunBowe s solution  But every answer here copies the whole string in memory at least once  The answers with ToCharArray   BlockCopy combo do it twice   If that matters here is a simple Stream wrapper for the raw UTF-16 string  If used with a StreamReader select Encoding Unicode for it   public class StringStream   Stream       private readonly string str       public override bool CanRead   gt  true      public override bool CanSeek   gt  true      public override bool CanWrite   gt  false      public override long Length   gt  str Length   2      public override long Position   get  set       TODO  bounds check      public StringStream string s    gt  str   s    throw new ArgumentNullException nameof s         public override long Seek long offset  SeekOrigin origin                switch  origin                        case SeekOrigin Begin                  Position   offset                  break              case SeekOrigin Current                  Position    offset                  break              case SeekOrigin End                  Position   Length - offset                  break                     return Position             private byte this int i    gt   i  amp  1     0    byte  str i   2   amp  0xFF     byte  str i   2   gt  gt  8        public override int Read byte   buffer  int offset  int count                   TODO  bounds check         var len   Math Min count  Length - Position           for  int i   0  i  lt  len  i                buffer offset      this  int  Position              return  int len             public override int ReadByte     gt  Position  gt   Length   -1   this  int Position         public override void Flush           public override void SetLength long value    gt  throw new NotSupportedException        public override void Write byte   buffer  int offset  int count    gt  throw new NotSupportedException        public override string ToString     gt  str                 And here is a more complete solution with necessary bound checks  derived from MemoryStream so it has ToArray and WriteTo methods as well

User · Answer

We use the extension methods listed below  I think you should make the developer make a decision about the encoding  so there is less magic involved   public static class StringExtensions        public static Stream ToStream this string s            return s ToStream Encoding UTF8              public static Stream ToStream this string s  Encoding encoding            return new MemoryStream encoding GetBytes s

User · Answer

Use the MemoryStream class  calling Encoding GetBytes to turn your string into an array of bytes first   Do you subsequently need a TextReader on the stream  If so  you could supply a StringReader directly  and bypass the MemoryStream and Encoding steps

User · Answer

Add this to a static string utility class   public static Stream ToStream this string str        MemoryStream stream   new MemoryStream        StreamWriter writer   new StreamWriter stream       writer Write str       writer Flush        stream Position   0      return stream      This adds an extension function so you can simply   using  var stringStream    My string  ToStream             use stringStream

User · Answer

Another solution   public static MemoryStream GenerateStreamFromString string value        return new MemoryStream Encoding UTF8 GetBytes value

User · Answer

Modernized and slightly modified version of the extension methods for ToStream   public static Stream ToStream this string value    gt  ToStream value  Encoding UTF8    public static Stream ToStream this string value  Encoding encoding                               gt  new MemoryStream encoding GetBytes value    string Empty        Modification as suggested in  Palec s comment of  Shaun Bowe answer

User · Answer

I used a mix of answers like this   public static Stream ToStream this string str  Encoding enc   null        enc   enc    Encoding UTF8      return new MemoryStream enc GetBytes str              And then I use it like this   String someStr  This is a Test   Encoding enc   getEncodingFromSomeWhere    using  Stream stream   someStr ToStream enc            Do something with the stream

[c#] How do I generate a stream from a string?

Examples related to c#

Examples related to unit-testing

Examples related to string

Examples related to stream