c# - bitmap not saving image to memory stream -

need little here. have app creating mergies 2 pictures together. issue when trying convert bitmap bitmpaimage display result on screen. can tell, image not being save memory stream @ "nwimg.save(memory,imageformat.jpeg);" ideas??

 //the code        //bitmap bitmapimage conversion             using (memorystream memory = new memorystream())             {//nwimg type bitmap, , @ point checked properties , values did copy on merging                 nwimg.save(memory, imageformat.jpeg);//here image nwimg.save suppose transfer memory                 memory.position = 0;                 nwbi.streamsource = memory;//memory stream showing null                 nwbi.cacheoption = bitmapcacheoption.onload;              } 

i don't know if matter nwimg represents bitmap created merging png image on top of jpeg. didn't read said matter figured through in there.

/// here code requested david //main c#

using system; using system.collections.generic; using system.linq; using system.text; using system.windows; using system.windows.controls; using system.windows.data; using system.windows.documents; using system.windows.input; using system.windows.media; using system.windows.media.imaging; using system.windows.navigation; using system.windows.shapes; using system.drawing; using system.io; using system.drawing.imaging;   namespace picmerger2 {     /// <summary>     /// interaction logic mainwindow.xaml     /// </summary>     public partial class mainwindow : window     {         pic currentpic = new pic();         bitmapimage bi = new bitmapimage(new uri("\\original photo.jpg"));         bitmapimage nwbi = new bitmapimage();         public mainwindow()         {             initializecomponent();              originalphoto.source = bi;             resultphoto.source = nwbi;          }          private void apply_click(object sender, routedeventargs e)         {             bitmap nwimg;             //bitmapimage bitmap conversion             using (memorystream outstream = new memorystream())             {                 bitmapencoder enc = new bmpbitmapencoder();                 enc.frames.add(bitmapframe.create(bi));                 enc.save(outstream);                 system.drawing.bitmap markthispic = new system.drawing.bitmap(outstream);                  // return bitmap; <-- leads problems, stream closed/closing ...                 nwimg = new bitmap(markthispic);             }             nwimg = currentpic.mergerthesetwo(nwimg);               //bitmap bitmapimage conversion             using (memorystream memory = new memorystream())             {                 nwimg.save(memory, imageformat.jpeg);                 memory.position = 0;                 nwbi.streamsource = memory;                 nwbi.cacheoption = bitmapcacheoption.onload;              }             resultphoto.source = nwbi;         }     } } 

//main xaml

<window x:class="picmerger2.mainwindow"         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"         title="mainwindow" height="350" width="525">     <grid horizontalalignment="center">         <stackpanel orientation="horizontal">             <stackpanel>                 <image x:name="originalphoto" height="200" stretch="uniformtofill" source="{binding}"></image>                 <label>original images</label>             </stackpanel>             <button x:name="apply" click="apply_click" height="25" >apply watermark</button>             <stackpanel>                 <image x:name="resultphoto" height="200" stretch="uniformtofill" source="{binding}"></image>                 <label>watermarked image</label>             </stackpanel>         </stackpanel>     </grid> </window> 

// pic class

using system; using system.collections.generic; using system.linq; using system.text; using system.drawing; using system.drawing.drawing2d;  namespace picmerger2 {     class pic     {         bitmap watermark = new bitmap(picmerger2.properties.resources._watermark);           public bitmap mergerthesetwo(bitmap bottomimage)         {             try             {                 using (var canvas = graphics.fromimage(bottomimage))                 {                     canvas.interpolationmode = interpolationmode.highqualitybicubic;                     //       canvas.drawimage(bottomimage, new rectangle(0, 0, bottomimage.width, bottomimage.height), new rectangle(0, 0, bottomimage.width, bottomimage.height), graphicsunit.pixel);                     canvas.drawimage(watermark, 0, 0);                     canvas.save();                      //save current picture                     bitmap newimage = new bitmap(bottomimage.width, bottomimage.height, canvas);                     return newimage;                 }             }             catch (exception)             {                  throw;             }         }     } } 

you need change couple of things code can work.

1. use following code bitmap bitmapimage conversion.

   using (memorystream memory = new memorystream()) {     nwimg.save(memory, imageformat.jpeg);     memory.position = 0;     nwbi = new bitmapimage();     nwbi.begininit();     nwbi.streamsource = memory;     nwbi.cacheoption = bitmapcacheoption.onload;     nwbi.endinit(); } 

2. inside pic class, replace these lines

   //save current picture bitmap newimage = new bitmap(bottomimage.width, bottomimage.height, canvas); return newimage; 

   to this

   return bottomimage; 

   since overload of bitmap class using, doesn't create new bitmap based on graphics object resolution (this results empty image). so, since draw onto bottomimage bitmap, need return image.