Android refresh image in viewpager -
i developing application show images using viewpager
. in app, have 5 pages , each page showing 1 image. , have button
can refresh 5 pages (means images different). here code:
imageadapter.java
public class imageadapter extends pageradapter { private context context; private list<integer> todayimage; imageadapter(context context, list<integer> todayimage) { this.context = context; this.todayimage = todayimage; } public void setimage(list<integer> todayimage) { this.todayimage = todayimage; } @override public int getcount() { return todayimage.size(); } @override public boolean isviewfromobject(view view, object object) { return view == ((imageview) object); } @override public object instantiateitem(viewgroup container, int position) { imageview imageview = new imageview(context); file imgfile = new file("data/data/com.project.project/" + todayimage.get(position) + ".jpg"); bitmap shufflebit = bitmapfactory.decodefile(imgfile.getabsolutepath()); imageview.setimagebitmap(shufflebit); ((viewpager) container).addview(imageview, 0); return imageview; } @override public void destroyitem(viewgroup container, int position, object object) { ((viewpager) container).removeview((imageview) object); } @override public int getitemposition(object object) { return position_none; } @override public void destroyitem(view collection, int position, object view) { ((viewpager) collection).removeview((view) view); } }
this button
use renew images:
shuffle.setonclicklistener(new onclicklistener() { public void onclick(view v) { adapter.setimage(newimage); });
this logcat:
05-03 01:17:50.793: e/androidruntime(716): fatal exception: main 05-03 01:17:50.793: e/androidruntime(716): java.lang.nullpointerexception 05-03 01:17:50.793: e/androidruntime(716): @ com.example.project.main$1.onclick(main.java:201) 05-03 01:17:50.793: e/androidruntime(716): @ android.view.view.performclick(view.java:4084) 05-03 01:17:50.793: e/androidruntime(716): @ android.view.view$performclick.run(view.java:16966) 05-03 01:17:50.793: e/androidruntime(716): @ android.os.handler.handlecallback(handler.java:615) 05-03 01:17:50.793: e/androidruntime(716): @ android.os.handler.dispatchmessage(handler.java:92) 05-03 01:17:50.793: e/androidruntime(716): @ android.os.looper.loop(looper.java:137) 05-03 01:17:50.793: e/androidruntime(716): @ android.app.activitythread.main(activitythread.java:4745) 05-03 01:17:50.793: e/androidruntime(716): @ java.lang.reflect.method.invokenative(native method) 05-03 01:17:50.793: e/androidruntime(716): @ java.lang.reflect.method.invoke(method.java:511) 05-03 01:17:50.793: e/androidruntime(716): @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java:786) 05-03 01:17:50.793: e/androidruntime(716): @ com.android.internal.os.zygoteinit.main(zygoteinit.java:553) 05-03 01:17:50.793: e/androidruntime(716): @ dalvik.system.nativestart.main(native method)
the app crashes when press button, can me how fix it? found answer using settag()
, have no idea how it.
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