image - Qt jpeg can't work on my friend's PC -

i finishing qt app, encounted problem. here it:

i use code load image qgraphicsscene:

qfile file(filename);         if(file.open(qfile::readonly)){             qbytearray data=file.readall ();             pixmapitem.loadfromdata (data,"jpeg");         } 

it works on computer, when give app friend, can't show image. googled , searched stack overflow issue, sounds need jpeg plugins.

so, this:

1. i copy qjpeg4.dll c:\qtsdk\qtcreator\bin\imageformats app root dir.---->failed.
2. i copy entire imageformats directory subdirectory of app toor dir. ---->also failed.

so, how can distribute app friends? works in computer, so, can work on others', can't it?

you have deploy qt dlls , plugin directories, see answer question qt dll deployment on windows.