android - Pass data from listview to main activity -

i have main activity included button , textview. when click button, display listview , fill data listview. in listview, click item, want send item data textview in main activity. however, has crash. have no idea find problem , log (does not show). @ code , provide me solution?

mainactivity

btnmanage = (button) findviewbyid(r.id.btnmanage); btnmanage.settext(managelabel); btnmanage.setonclicklistener(new view.onclicklistener() {     @override     public void onclick(final view v) {         intent intent = new intent(v.getcontext(), listviewactivity.class);         intent.putextra("list_data", "hello");         v.getcontext().startactivity(intent);      } }); 

in listviewactivity have

bundle bundle = getintent().getextras(); string data_string= bundle.getstring("list_data"); arraylist<string> data = new arraylist<string>(); data.add(data_string); listadapter = new arrayadapter<string>(this, r.layout.simplerow, data);     // set arrayadapter listview's adapter. mainlistview.setadapter( listadapter );  //click 1 item public void onitemclick(adapterview<?> parent, view view, int position,       long id) {  string  data_send    = (string) mainlistview.getitematposition(position); intent intent = new intent(this, mainactivity.class); intent.putextra("data_send", data_send); startactivity(intent);  } 

in oncreate function in mainactivity, have

bundle bundle = getintent().getextras(); string data_activity =bundle.getstring("data_send"); 

the manifest file

    <activity         android:name=".mainactivity"         android:label="@string/app_name">         <intent-filter>             <action android:name="android.intent.action.main" />             <category android:name="android.intent.category.launcher" />         </intent-filter>     </activity>     <activity         android:name=".listviewactivity"         android:label="@string/app_name"          android:screenorientation="portrait"     /> 

in listviewactivity trying start mainactivity started hence error.

you need finish listviewactivity acivity goes previous activity mainactivity , pass data

in listviewactivity finish activity , pass data this

intent intent = new intent(); intent.putextra("data_send", data_send); setresult(result_ok, intent); finish(); 

in mainactivity start listviewactivity this

intent = new intent(getapplicationcontext(), listviewactivity.class); i.putextra("list_data", "hello"); startactivityforresult(i, 1); 

also in mainactivity need data listviewactivity add

public void onactivityresult(int requestcode, int resultcode, intent data) {          if (requestcode == 1) {             if (resultcode == result_ok) {                 string data = data.getstringextra("data_send");                // whatever data string }}}; 

the if (requestcode == 1) { number id give when start activity startactivityforresult(i, 1);. if want same activity can startactivityforresult(i, 2); , data check id 2 if (requestcode == 2) { ...