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  1. using System;
  2. using System.Drawing;
  3. using System.Drawing.Drawing2D;
  4. using System.Drawing.Imaging;
  5. using System.IO;
  6.  
  7. class Program
  8. {
  9.     static void Main(string[] args)
  10.     {
  11.         byte[] bytes;
  12.         using (var td = new Bitmap(500, 500))
  13.         using (var lgb = new LinearGradientBrush(new Point(0, 0), new Point(td.Width, td.Height), Color.Red, Color.Green))
  14.         using (var g = Graphics.FromImage(td))
  15.         {
  16.             g.FillRectangle(lgb, 0, 0, td.Width, td.Height);
  17.  
  18.             using (var ms = new MemoryStream())
  19.             {
  20.                 td.Save(ms, ImageFormat.Jpeg);
  21.                 bytes = ms.ToArray();
  22.             }
  23.         }
  24.  
  25.         Image img;
  26.         using (var s = new TestStream(bytes))
  27.         {
  28.             img = Image.FromStream(s);
  29.             Console.WriteLine("Image.FromStream");
  30.         }
  31.         img.Save("a.jpg");
  32.         Console.WriteLine("Image.Save");
  33.  
  34.         Console.ReadKey();
  35.     }
  36. }
  37.  
  38. internal class TestStream : Stream
  39. {
  40.     private readonly byte[] _Data;
  41.     private int _Position;
  42.  
  43.     internal TestStream(byte[] array)
  44.     {
  45.         _Data = array;
  46.     }
  47.  
  48.     public override bool CanRead
  49.     {
  50.         get
  51.         {
  52.             return true;
  53.         }
  54.     }
  55.  
  56.     public override bool CanSeek
  57.     {
  58.         get
  59.         {
  60.             return true;
  61.         }
  62.     }
  63.  
  64.     public override bool CanWrite
  65.     {
  66.         get
  67.         {
  68.             return false;
  69.         }
  70.     }
  71.  
  72.     public override void Flush()
  73.     {
  74.     }
  75.  
  76.     public override long Length
  77.     {
  78.         get
  79.         {
  80.             return _Data.Length;
  81.         }
  82.     }
  83.  
  84.     public override long Position
  85.     {
  86.         get
  87.         {
  88.             return _Position;
  89.         }
  90.         set
  91.         {
  92.             _Position = Math.Min(Math.Max(0, (int)value), _Data.Length);
  93.         }
  94.     }
  95.  
  96.     public override int Read(byte[] buffer, int offset, int count)
  97.     {
  98.         var l = Math.Min(count, _Data.Length - _Position);
  99.         if (l <= 0)
  100.         {
  101.             return 0;
  102.         }
  103.  
  104.         Console.WriteLine("Stream.Read {0}, {1}", _Position, l);
  105.  
  106.         Array.Copy(_Data, _Position, buffer, offset, l);
  107.         _Position += l;
  108.         return l;
  109.     }
  110.  
  111.     public override long Seek(long offset, SeekOrigin origin)
  112.     {
  113.         switch (origin)
  114.         {
  115.             case SeekOrigin.Begin:
  116.                 Position = offset;
  117.                 break;
  118.             case SeekOrigin.Current:
  119.                 Position += offset;
  120.                 break;
  121.             case SeekOrigin.End:
  122.                 Position = _Data.Length + offset;
  123.                 break;
  124.         }
  125.         return Position;
  126.     }
  127.  
  128.     public override void SetLength(long value)
  129.     {
  130.         throw new NotSupportedException();
  131.     }
  132.  
  133.     public override void Write(byte[] buffer, int offset, int count)
  134.     {
  135.         throw new NotSupportedException();
  136.     }
  137. }
  138.  
  139.  
Runtime error #stdin #stdout 0.11s 47072KB
comments (?)
stdin
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Standard input is empty
stdout
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Stream.Read 0, 44
Stream.Read 44, 5768
Image.FromStream
https://ideone.com/9PWfWv
language:
C# (gmcs 5.20.1)
created:
11 years ago
visibility:
secret

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