java - Zxing barcode scanner implementation intent -

i've been looking everywhere regarding implementing barcode scanner application/ i've included code which'll enable user scan if barcode scanner installed need prompt user download application if isn't installed? followed example me far.

here code

    package com.example.zxingscan;  import android.os.bundle; import android.app.activity; import android.content.intent; import android.view.view; import android.view.view.onclicklistener; import android.widget.textview;  public class main extends activity {   @override   public void oncreate(bundle savedinstancestate) {      super.oncreate(savedinstancestate);      setcontentview(r.layout.activity_main);      handleclick hc = new handleclick();      findviewbyid(r.id.butqr).setonclicklistener(hc);    }    private class handleclick implements onclicklistener{      public void onclick(view arg0) {        intent intent = new intent("com.google.zxing.client.android.scan");        switch(arg0.getid()){          case r.id.butqr:            intent.putextra("scan_mode", "qr_code_mode");          break;         }       startactivityforresult(intent, 0);    //barcode scanner scan     }   }   public void onactivityresult(int requestcode, int resultcode, intent intent) {     if (requestcode == 0) {       textview tvstatus=(textview)findviewbyid(r.id.tvstatus);       textview tvresult=(textview)findviewbyid(r.id.tvresult);       if (resultcode == result_ok) {         tvstatus.settext(intent.getstringextra("scan_result_format"));         tvresult.settext(intent.getstringextra("scan_result"));       } else if (resultcode == result_canceled) {         tvstatus.settext("press button start scan.");         tvresult.settext("scan cancelled.");       }     }   } } 

first of create dialog briefly explains situation , suggests install free zxing scanner app google play. add cancel , install button. i'm not going explain how here. take @ alertdialog.builder tutorial example.

upon user confirmation (install button click) need start following intent:

startactivity(new intent(intent.action_view,     uri.parse("market://details?id=com.google.zxing.client.android"))); 

market protocol uris can used open app detail pages google play market. see this android documentation page more information.