c# - Image processing from the client through TCP socket failed -

i developing application viewing client screen on tcp socket. server application in c# , client application in c++. send image server without error. @ server end, while converting buffer length getting big number , causes 'overflow exception' while making image buffer size. following code have tried.

server code

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public static void startlistening() {     // data buffer incoming data.     byte[] bytes = new byte[1024];      // establish local endpoint socket.     // dns name of computer     // running listener "host.contoso.com".     iphostentry iphostinfo = dns.gethostentry("127.0.0.1");     ipaddress ipaddress = iphostinfo.addresslist[0];     ipendpoint localendpoint = new ipendpoint(ipaddress.parse("127.0.0.1"), 11000);      // create tcp/ip socket.     socket listener = new socket(addressfamily.internetwork,         sockettype.stream, protocoltype.tcp);      // bind socket local endpoint , listen incoming connections.     try     {         listener.bind(localendpoint);         listener.listen(100);          while (true)         {             // set event nonsignaled state.             alldone.reset();              // start asynchronous socket listen connections.             console.writeline("waiting connection...");             listener.beginaccept(                 new asynccallback(acceptcallback),                 listener);              // wait until connection made before continuing.             alldone.waitone();         }      }     catch (exception e)     {         console.writeline(e.tostring());     }      console.writeline("\npress enter continue...");     console.read();  }  public static void acceptcallback(iasyncresult ar) {     // signal main thread continue.     alldone.set();      // socket handles client request.     socket listener = (socket)ar.asyncstate;     socket handler = listener.endaccept(ar);      // create state object.     stateobject state = new stateobject();     state.worksocket = handler;     handler.beginreceive(state.buffer, 0, stateobject.buffersize, 0,         new asynccallback(readheadercallback), state); }  public static void readheadercallback(iasyncresult ar) {     // retrieve state object , handler socket     // asynchronous state object.     stateobject state = (stateobject)ar.asyncstate;     socket handler = state.worksocket;      // read data client socket.      int bytesread = handler.endreceive(ar);      //we need add error handler here...but later     state.imagesize = bitconverter.toint32(state.buffer, 0);     _imagebuff = new byte[state.imagesize];     _totbytesread = 0;     handler.beginreceive(state.buffer, 0, stateobject.buffersize, 0,        new asynccallback(readcallback), state); }  public static void readcallback(iasyncresult ar) {     string content = string.empty;      // retrieve state object , handler socket     // asynchronous state object.     stateobject state = (stateobject)ar.asyncstate;     socket handler = state.worksocket;      // read data client socket.      int bytesread = handler.endreceive(ar);       if (bytesread > 0)     {         // there  might more data, store data received far.         buffer.blockcopy(state.buffer, 0, _imagebuff, _totbytesread, bytesread);          _totbytesread += bytesread;          if (_totbytesread < state.imagesize)         {             // not data received. more.             handler.beginreceive(state.buffer, 0, stateobject.buffersize, 0,             new asynccallback(readcallback), state);         }         else         {             file.writeallbytes(@"c:\temp\incoming\untitled.bmp", _imagebuff);         }     } } public static int main(string[] args) {     startlistening();     return 0; } 

client code

void sendscreen() { hdc hdcscreen; hdc hdcwindow; hdc hdcmemdc = null; hbitmap hbmscreen = null; bitmap bmpscreen;  hwnd hwnd = getdesktopwindow();  // retrieve handle display device context client  // area of window.  hdcscreen = getdc(null); hdcwindow = getdc(hwnd);  // create compatible dc used in bitblt window dc hdcmemdc = createcompatibledc(hdcwindow);   if(!hdcmemdc) {     //messagebox(hwnd, l"createcompatibledc has failed",l"failed", mb_ok);     goto done; }  // client area size calculation rect rcclient; getclientrect(hwnd,&rcclient);  //this best stretch mode setstretchbltmode(hdcwindow,halftone);  //the source dc entire screen , destination dc current  window (hwnd) if(!stretchblt(hdcwindow,             0,0,             rcclient.right, rcclient.bottom,             hdcscreen,             0,0,            getsystemmetrics (sm_cxscreen),            getsystemmetrics (sm_cyscreen),            srccopy))     {     messagebox(hwnd, "stretchblt has failed","failed", mb_ok);     goto done; }  // create compatible bitmap window dc hbmscreen = createcompatiblebitmap(hdcwindow, rcclient.right-rcclient.left,  rcclient.bottom-rcclient.top);  if(!hbmscreen) {     messagebox(hwnd, "createcompatiblebitmap failed","failed", mb_ok);     goto done; }  // select compatible bitmap compatible memory dc. selectobject(hdcmemdc,hbmscreen);  // bit block transfer our compatible memory dc. if(!bitblt(hdcmemdc,             0,0,             rcclient.right-rcclient.left, rcclient.bottom-rcclient.top,             hdcwindow,             0,0,            srccopy))    {     messagebox(hwnd, "bitblt has failed", "failed", mb_ok);     goto done;    }  // bitmap hbitmap getobject(hbmscreen,sizeof(bitmap),&bmpscreen);  bitmapfileheader   bmfheader;     bitmapinfoheader   bi;  bi.bisize = sizeof(bitmapinfoheader);     bi.biwidth = bmpscreen.bmwidth;     bi.biheight = bmpscreen.bmheight;   bi.biplanes = 1;     bi.bibitcount = 32;     bi.bicompression = bi_rgb;     bi.bisizeimage = 0;   bi.bixpelspermeter = 0;     bi.biypelspermeter = 0;     bi.biclrused = 0;     bi.biclrimportant = 0;  dword dwbmpsize = ((bmpscreen.bmwidth  bi.bibitcount + 31) / 32)  4 *  bmpscreen.bmheight; handle hdib = globalalloc(ghnd,dwbmpsize);  char lpbitmap = (char )globallock(hdib);     getdibits(hdcwindow, hbmscreen, 0,     (uint)bmpscreen.bmheight,     lpbitmap,     (bitmapinfo *)&bi, dib_rgb_colors); handle hfile = createfile("capture.bmp",     generic_write,     0,     null,     create_always,     file_attribute_normal, null);     // add size of headers size of bitmap total file size dword dwsizeofdib = dwbmpsize + sizeof(bitmapfileheader) + sizeof(bitmapinfoheader);  //offset actual bitmap bits start. bmfheader.bfoffbits = (dword)sizeof(bitmapfileheader) + (dword)sizeof(bitmapinfoheader);   //size of file bmfheader.bfsize = dwsizeofdib;   //bftype must bm bitmaps bmfheader.bftype = 0x4d42; //bm       dword dwbyteswritten = 0; writefile(hfile, (lpstr)&bmfheader, sizeof(bitmapfileheader), &dwbyteswritten, null); writefile(hfile, (lpstr)&bi, sizeof(bitmapinfoheader), &dwbyteswritten, null); writefile(hfile, (lpstr)lpbitmap, dwbmpsize, &dwbyteswritten, null); sendingtosocketbfh(bmfheader); sendingtosocketbih(bi); sendingtosocket(lpbitmap,dwbmpsize);   //unlock , free dib heap globalunlock(hdib);     globalfree(hdib);  //close handle file created closehandle(hfile);  //clean done: deleteobject(hbmscreen); deleteobject(hdcmemdc); releasedc(null,hdcscreen); releasedc(hwnd,hdcwindow); }  void sendingtosocketbfh(bitmapfileheader bfinfo) { dword dwerr=0; int sent=0; sent = send((char*)&bfinfo,sizeof(bfinfo),0); dwerr = getlasterror(); }  void sendingtosocketbih(bitmapinfoheader binfo) { dword dwerr=0; int sent=0; sent = send((char*)&binfo,sizeof(binfo),0); dwerr = getlasterror(); }  void sendingtosocket(char* cpbuff,int ilen) { dword dwerr=0; int sent=0; sent = send(cpbuff,ilen,0); dwerr = getlasterror(); }