java - Built-in Navigation Drawer Activity (on click event) -

i decided make application uses navigation drawer. created app. using built-in navigation drawer activity ( android studio ) make idea of contains, launched on phone.it works smooth but, want new activity show when press on item drawer panel. how do that?

this mainactivity.java

import android.app.activity; import android.app.actionbar; import android.app.fragment; import android.app.fragmentmanager; import android.content.context; import android.os.build; import android.os.bundle; import android.view.gravity; import android.view.layoutinflater; import android.view.menu; import android.view.menuitem; import android.view.view; import android.view.viewgroup; import android.support.v4.widget.drawerlayout; import android.widget.arrayadapter; import android.widget.textview;   public class mainactivity extends activity         implements navigationdrawerfragment.navigationdrawercallbacks {      /**      * fragment managing behaviors, interactions , presentation of navigation drawer.      */     private navigationdrawerfragment mnavigationdrawerfragment;      /**      * used store last screen title. use in {@link #restoreactionbar()}.      */     private charsequence mtitle;      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);          mnavigationdrawerfragment = (navigationdrawerfragment)                 getfragmentmanager().findfragmentbyid(r.id.navigation_drawer);         mtitle = gettitle();          // set drawer.         mnavigationdrawerfragment.setup(                 r.id.navigation_drawer,                 (drawerlayout) findviewbyid(r.id.drawer_layout));     }      @override     public void onnavigationdraweritemselected(int position) {         // update main content replacing fragments         fragmentmanager fragmentmanager = getfragmentmanager();         fragmentmanager.begintransaction()                 .replace(r.id.container, placeholderfragment.newinstance(position + 1))                 .commit();     }      public void onsectionattached(int number) {         switch (number) {             case 1:                 mtitle = getstring(r.string.title_section1);                 break;             case 2:                 mtitle = getstring(r.string.title_section2);                 break;             case 3:                 mtitle = getstring(r.string.title_section3);                 break;             case 4:                 mtitle = getstring(r.string.title_section4);                 break;         }     }      public void restoreactionbar() {         actionbar actionbar = getactionbar();         actionbar.setnavigationmode(actionbar.navigation_mode_standard);         actionbar.setdisplayshowtitleenabled(true);         actionbar.settitle(mtitle);     }       @override     public boolean oncreateoptionsmenu(menu menu) {         if (!mnavigationdrawerfragment.isdraweropen()) {             // show items in action bar relevant screen             // if drawer not showing. otherwise, let drawer             // decide show in action bar.             getmenuinflater().inflate(r.menu.main, menu);             restoreactionbar();             return true;         }         return super.oncreateoptionsmenu(menu);     }      @override     public boolean onoptionsitemselected(menuitem item) {         // handle action bar item clicks here. action bar         // automatically handle clicks on home/up button, long         // specify parent activity in androidmanifest.xml.         int id = item.getitemid();          //noinspection simplifiableifstatement         if (id == r.id.action_settings) {             return true;         }          return super.onoptionsitemselected(item);     }      /**      * placeholder fragment containing simple view.      */     public static class placeholderfragment extends fragment {         /**          * fragment argument representing section number          * fragment.          */         private static final string arg_section_number = "section_number";          /**          * returns new instance of fragment given section          * number.          */         public static placeholderfragment newinstance(int sectionnumber) {             placeholderfragment fragment = new placeholderfragment();             bundle args = new bundle();             args.putint(arg_section_number, sectionnumber);             fragment.setarguments(args);             return fragment;         }          public placeholderfragment() {         }          @override         public view oncreateview(layoutinflater inflater, viewgroup container,                                  bundle savedinstancestate) {             view rootview = inflater.inflate(r.layout.fragment_main, container, false);             return rootview;         }          @override         public void onattach(activity activity) {             super.onattach(activity);             ((mainactivity) activity).onsectionattached(                     getarguments().getint(arg_section_number));         }     }  } 

here's navigationdrawerfragment.java:

import android.app.activity; import android.app.actionbar; import android.app.fragment; import android.support.v4.app.actionbardrawertoggle; import android.support.v4.view.gravitycompat; import android.support.v4.widget.drawerlayout; import android.content.sharedpreferences; import android.content.res.configuration; import android.os.bundle; import android.preference.preferencemanager; import android.view.layoutinflater; import android.view.menu; import android.view.menuinflater; import android.view.menuitem; import android.view.view; import android.view.viewgroup; import android.widget.adapterview; import android.widget.arrayadapter; import android.widget.listview; import android.widget.toast;  /**  * fragment used managing interactions , presentation of navigation drawer.  * see <a href="https://developer.android.com/design/patterns/navigation-drawer.html#interaction">  * design guidelines</a> complete explanation of behaviors implemented here.  */ public class navigationdrawerfragment extends fragment {      /**      * remember position of selected item.      */     private static final string state_selected_position = "selected_navigation_drawer_position";      /**      * per design guidelines, should show drawer on launch until user manually      * expands it. shared preference tracks this.      */     private static final string pref_user_learned_drawer = "navigation_drawer_learned";      /**      * pointer current callbacks instance (the activity).      */     private navigationdrawercallbacks mcallbacks;      /**      * helper component ties action bar navigation drawer.      */     private actionbardrawertoggle mdrawertoggle;      private drawerlayout mdrawerlayout;     private listview mdrawerlistview;     private view mfragmentcontainerview;      private int mcurrentselectedposition = 0;     private boolean mfromsavedinstancestate;     private boolean muserlearneddrawer;      public navigationdrawerfragment() {     }      @override     public void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          // read in flag indicating whether or not user has demonstrated awareness of         // drawer. see pref_user_learned_drawer details.         sharedpreferences sp = preferencemanager.getdefaultsharedpreferences(getactivity());         muserlearneddrawer = sp.getboolean(pref_user_learned_drawer, false);          if (savedinstancestate != null) {             mcurrentselectedposition = savedinstancestate.getint(state_selected_position);             mfromsavedinstancestate = true;         }          // select either default item (0) or last selected item.         selectitem(mcurrentselectedposition);     }      @override     public void onactivitycreated(bundle savedinstancestate) {         super.onactivitycreated(savedinstancestate);         // indicate fragment influence set of actions in action bar.         sethasoptionsmenu(true);     }      @override     public view oncreateview(layoutinflater inflater, viewgroup container,                              bundle savedinstancestate) {         mdrawerlistview = (listview) inflater.inflate(                 r.layout.fragment_navigation_drawer, container, false);         mdrawerlistview.setonitemclicklistener(new adapterview.onitemclicklistener() {             @override             public void onitemclick(adapterview<?> parent, view view, int position, long id) {                 selectitem(position);             }         });         mdrawerlistview.setadapter(new arrayadapter<string>(                 getactionbar().getthemedcontext(),                 android.r.layout.simple_list_item_activated_1,                 android.r.id.text1,                 new string[]{                         getstring(r.string.title_section1),                         getstring(r.string.title_section2),                         getstring(r.string.title_section3),                         getstring(r.string.title_section4),                 }));         mdrawerlistview.setitemchecked(mcurrentselectedposition, true);         return mdrawerlistview;     }      public boolean isdraweropen() {         return mdrawerlayout != null && mdrawerlayout.isdraweropen(mfragmentcontainerview);     }      /**      * users of fragment must call method set navigation drawer interactions.      *      * @param fragmentid   android:id of fragment in activity's layout.      * @param drawerlayout drawerlayout containing fragment's ui.      */     public void setup(int fragmentid, drawerlayout drawerlayout) {         mfragmentcontainerview = getactivity().findviewbyid(fragmentid);         mdrawerlayout = drawerlayout;          // set custom shadow overlays main content when drawer opens         mdrawerlayout.setdrawershadow(r.drawable.drawer_shadow, gravitycompat.start);         // set drawer's list view items , click listener          actionbar actionbar = getactionbar();         actionbar.setdisplayhomeasupenabled(true);         actionbar.sethomebuttonenabled(true);          // actionbardrawertoggle ties the proper interactions         // between navigation drawer , action bar app icon.         mdrawertoggle = new actionbardrawertoggle(                 getactivity(),                    /* host activity */                 mdrawerlayout,                    /* drawerlayout object */                 r.drawable.ic_drawer,             /* nav drawer image replace 'up' caret */                 r.string.navigation_drawer_open,  /* "open drawer" description accessibility */                 r.string.navigation_drawer_close  /* "close drawer" description accessibility */         ) {             @override             public void ondrawerclosed(view drawerview) {                 super.ondrawerclosed(drawerview);                 if (!isadded()) {                     return;                 }                  getactivity().invalidateoptionsmenu(); // calls onprepareoptionsmenu()             }              @override             public void ondraweropened(view drawerview) {                 super.ondraweropened(drawerview);                 if (!isadded()) {                     return;                 }                  if (!muserlearneddrawer) {                     // user manually opened drawer; store flag prevent auto-showing                     // navigation drawer automatically in future.                     muserlearneddrawer = true;                     sharedpreferences sp = preferencemanager                             .getdefaultsharedpreferences(getactivity());                     sp.edit().putboolean(pref_user_learned_drawer, true).apply();                 }                  getactivity().invalidateoptionsmenu(); // calls onprepareoptionsmenu()             }         };          // if user hasn't 'learned' drawer, open introduce them drawer,         // per navigation drawer design guidelines.         if (!muserlearneddrawer && !mfromsavedinstancestate) {             mdrawerlayout.opendrawer(mfragmentcontainerview);         }          // defer code dependent on restoration of previous instance state.         mdrawerlayout.post(new runnable() {             @override             public void run() {                 mdrawertoggle.syncstate();             }         });          mdrawerlayout.setdrawerlistener(mdrawertoggle);     }      private void selectitem(int position) {         mcurrentselectedposition = position;         if (mdrawerlistview != null) {             mdrawerlistview.setitemchecked(position, true);         }         if (mdrawerlayout != null) {             mdrawerlayout.closedrawer(mfragmentcontainerview);         }         if (mcallbacks != null) {             mcallbacks.onnavigationdraweritemselected(position);         }     }      @override     public void onattach(activity activity) {         super.onattach(activity);         try {             mcallbacks = (navigationdrawercallbacks) activity;         } catch (classcastexception e) {             throw new classcastexception("activity must implement navigationdrawercallbacks.");         }     }      @override     public void ondetach() {         super.ondetach();         mcallbacks = null;     }      @override     public void onsaveinstancestate(bundle outstate) {         super.onsaveinstancestate(outstate);         outstate.putint(state_selected_position, mcurrentselectedposition);     }      @override     public void onconfigurationchanged(configuration newconfig) {         super.onconfigurationchanged(newconfig);         // forward new configuration drawer toggle component.         mdrawertoggle.onconfigurationchanged(newconfig);     }      @override     public void oncreateoptionsmenu(menu menu, menuinflater inflater) {         // if drawer open, show global app actions in action bar. see         // showglobalcontextactionbar, controls top-left area of action bar.         if (mdrawerlayout != null && isdraweropen()) {             inflater.inflate(r.menu.global, menu);             showglobalcontextactionbar();         }         super.oncreateoptionsmenu(menu, inflater);     }      @override     public boolean onoptionsitemselected(menuitem item) {         if (mdrawertoggle.onoptionsitemselected(item)) {             return true;         }          if (item.getitemid() == r.id.action_example) {             toast.maketext(getactivity(), "example action.", toast.length_short).show();             return true;         }          return super.onoptionsitemselected(item);     }      /**      * per navigation drawer design guidelines, updates action bar show global app      * 'context', rather what's in current screen.      */     private void showglobalcontextactionbar() {         actionbar actionbar = getactionbar();         actionbar.setdisplayshowtitleenabled(true);         actionbar.setnavigationmode(actionbar.navigation_mode_standard);         actionbar.settitle(r.string.app_name);     }      private actionbar getactionbar() {         return getactivity().getactionbar();     }      /**      * callbacks interface activities using fragment must implement.      */     public static interface navigationdrawercallbacks {         /**          * called when item in navigation drawer selected.          */         void onnavigationdraweritemselected(int position);     } } 

and activity_main.xml:

<android.support.v4.widget.drawerlayout     xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:id="@+id/drawer_layout"     android:layout_width="match_parent"     android:layout_height="match_parent"     tools:context=".mainactivity">       <framelayout         android:id="@+id/container"         android:layout_width="match_parent"         android:layout_height="match_parent" />       <fragment         android:id="@+id/navigation_drawer"         android:layout_width="@dimen/navigation_drawer_width"         android:layout_height="match_parent"         android:layout_gravity="start"         android:name="com.alec.drawertest.navigationdrawerfragment"         tools:layout="@layout/fragment_navigation_drawer" />  </android.support.v4.widget.drawerlayout> 

this code of yours listens click event:

mdrawerlistview.setonitemclicklistener(new adapterview.onitemclicklistener() {         @override         public void onitemclick(adapterview<?> parent, view view, int position, long id) {             selectitem(position);         }     }); 

position item no. of navigation drawer item clicked. can use switch case identify item clicked , call startactivity using

intent intent = new intent(this, displaymessageactivity.class); startactivity(intent); 

your selectitem should this:

private void selectitem(int position) { intent intent; switch (position) {     case 0:             intent = new intent(currentactivity, newactivity.class);             intent.addflags(intent.flag_activity_clear_top);             currentactivity.startactivity(intent);          break;     case 1: // etc.