android - Using the phone's camera -

i m making app uses camera send data surfaceholder . when call addcallback() app crashes. here code :

public class cam_view extends activity implements surfaceholder.callback{  private surfaceview camview; private surfaceholder camholder; private boolean previewrunning;  protected void oncreate(bundle savedinstancestate) { super.oncreate(savedinstancestate); setcontentview(r.layout.camera);  camview = (surfaceview)findviewbyid(r.id.sview); camholder = camview.getholder(); camholder.addcallback(this); camholder.settype(surfaceholder.surface_type_push_buffers); }} 

and unimplemented methods :

 @override   public void surfacechanged(surfaceholder holder, int format, int width,     int height) { if(previewrunning){     camera.stoppreview(); } camera.parameters camparams = camera.getparameters(); camparams.setpreviewformat(pixelformat.jpeg); camera.setparameters(camparams); try{     camera.setpreviewdisplay(holder);     camera.startpreview();     previewrunning=true; }catch(ioexception e){     e.printstacktrace(); }  }    public void surfacecreated(surfaceholder holder) { try{     camera=camera.open(); }catch(exception e){     e.printstacktrace();     toast.maketext(getapplicationcontext(),"error",toast.length_long).show();     finish(); }  }    @override   public void surfacedestroyed(surfaceholder holder) { camera.stoppreview(); camera.release(); camera=null;   } 

why app crash when call
camholder.addcallback(this); ? there other problems in code ?

i tried above code.its working fine on device. able launch camera successfully. dont think problem in camholder.addcallback(this);

problem in line

camparams.setpreviewformat(pixelformat.jpeg);

update with

camera.size size = camparams.getsupportedpreviewsizes().get(0); camparams.setpreviewsize(size.width, size.height);

your code work.

also make sure below things added.

1) sview named surfaceview exits in layout

2) add camera permission - "android.permission.camera"

if problem still occurs, please share logs.