android - updating and deleting row in listview -

i know question not new, other examples found here didnt work. thats why writing you.

i created book application, can save bookdata googlebooks , can save data sqlite db. bookdata displayed in listview. if click on row, data of row displayed in edittexts in activity - looks detailed book view. example pictures: listview ; detailed bookview

now want give possibility user edit these bookinfos. implemented code update , delte info , info logcat, db created when go listview no data updated or deleted.

i used video called "android studio tutorial - 37 - update database" youtube convert solution

maybe can me.

following code book info:

protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_book_info);         bookdbhelper = new bookdbhelper(this);         typeface mytypeface = typeface.createfromasset(getassets(), "lobster.ttf");         textview mytextview = (textview) findviewbyid(r.id.yourbookinfo);         mytextview.settypeface(mytypeface);          btn_update = (button) findviewbyid(r.id.button_update);          intent intent = getintent();          string secret_title = intent.getstringextra(bookdatalistactivity.extra_msg1);         secret_edittext_title = (edittext) findviewbyid(r.id.secret_edittext_title);         secret_edittext_title.settext(secret_title);          string book_title = intent.getstringextra(bookdatalistactivity.extra_msg1);         passedbooktitle = (edittext) findviewbyid(r.id.passed_booktitle);         passedbooktitle.settext(book_title);          string book_author = intent.getstringextra(bookdatalistactivity.extra_msg2);         passedbookauthor = (edittext) findviewbyid(r.id.passed_bookauthor);         passedbookauthor.settext(book_author);          string book_date = intent.getstringextra(bookdatalistactivity.extra_msg3);         passedbookdate = (edittext) findviewbyid(r.id.passed_bookdate);         passedbookdate.settext(book_date);          string book_rating = intent.getstringextra(bookdatalistactivity.extra_msg4);         passedbookrating = (edittext) findviewbyid(r.id.passed_bookrating);         passedbookrating.settext(book_rating);          string book_shelf = intent.getstringextra(bookdatalistactivity.extra_msg5);         passedbookshelf = (edittext) findviewbyid(r.id.passed_bookshelf);         passedbookshelf.settext(book_shelf);      }       public void updatebookinfo(view view){         bookdbhelper = new bookdbhelper(getapplicationcontext());         sqlitedatabasebooks = bookdbhelper.getwritabledatabase();          secret_edittext_titel = secret_edittext_title.gettext().tostring();          string booktitle, bookauthor, bookdate, bookrating, bookshelf;         booktitle = passedbooktitle.gettext().tostring();         bookauthor = passedbookauthor.gettext().tostring();         bookdate = passedbookdate.gettext().tostring();         bookrating = passedbookrating.gettext().tostring();         bookshelf = passedbookshelf.gettext().tostring();         int count = bookdbhelper.updateeditedbookinfo(secret_edittext_titel,                 booktitle,bookauthor, bookdate, bookrating, bookshelf, sqlitedatabasebooks);         toast.maketext(getapplicationcontext(), count+" book updated", toast.length_long).show();         finish();      }      public void deletebook(view view){         bookdbhelper = new bookdbhelper(getapplicationcontext());         sqlitedatabasebooks = bookdbhelper.getwritabledatabase();         bookdbhelper.deletebookinformation(secret_edittext_titel, sqlitedatabasebooks);         toast.maketext(getbasecontext(), "book deleted", toast.length_long).show();     } 

and bookdbhelper:

public int updateeditedbookinfo(string old_title, string new_title, string new_author,                                      string new_date, string new_rating,                                      string new_shelf, sqlitedatabase sqlitedatabase){         contentvalues contentvalues = new contentvalues();         contentvalues.put(bookcontent.newbookinfo.book_title, new_title);         contentvalues.put(bookcontent.newbookinfo.book_author, new_author);         contentvalues.put(bookcontent.newbookinfo.book_date, new_date);         contentvalues.put(bookcontent.newbookinfo.book_rating, new_rating);         contentvalues.put(bookcontent.newbookinfo.book_shelf, new_shelf);          string selection = bookcontent.newbookinfo.book_title + " = ?";         string [] selection_args = {old_title};         int count =  sqlitedatabase.update(bookcontent.newbookinfo.table_name_books, contentvalues, selection, selection_args);         return count;     }      public void deletebookinformation(string book_title,sqlitedatabase sqlitedatabase){     string selection = bookcontent.newbookinfo.book_title+ "  =?";     string [] selection_args = {book_title};     sqlitedatabase.delete(bookcontent.newbookinfo.table_name_books, selection, selection_args); } 

edit asked activity_book_info.xml

<?xml version="1.0" encoding="utf-8"?>     <relativelayout xmlns:android="http://schemas.android.com/apk/res/android"     xmlns:tools="http://schemas.android.com/tools"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:paddingbottom="@dimen/activity_vertical_margin"     android:paddingleft="@dimen/activity_horizontal_margin"     android:paddingright="@dimen/activity_horizontal_margin"     android:paddingtop="@dimen/activity_vertical_margin"     tools:context="com.kasutwentyseven.gui4selfshelf.books.bookinfoactivity"     android:background="@color/background">      <textview         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:text="@string/yourbookinfo"         android:id="@+id/yourbookinfo"         android:textsize="25dp"         android:textcolor="@color/textcolor"         android:gravity="center_horizontal"         android:textstyle="bold"         />      <linearlayout         android:orientation="horizontal"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/yourbookinfo"         android:layout_alignparentstart="true"         android:id="@+id/linearlayout5">          <linearlayout             android:orientation="horizontal"             android:layout_width="match_parent"             android:layout_height="wrap_content">              <imageview                 android:layout_width="100dp"                 android:layout_height="match_parent"                 android:id="@+id/passed_bookimage" />              <linearlayout                 android:orientation="vertical"                 android:layout_width="match_parent"                 android:layout_height="match_parent">                  <edittext                     android:layout_width="match_parent"                     android:layout_height="wrap_content"                     android:id="@+id/passed_booktitle" />                  <edittext                     android:layout_width="match_parent"                     android:layout_height="wrap_content"                     android:id="@+id/passed_bookauthor" />                  <edittext                     android:layout_width="match_parent"                     android:layout_height="wrap_content"                     android:id="@+id/passed_bookdate" />                  <edittext                     android:layout_width="match_parent"                     android:layout_height="wrap_content"                     android:id="@+id/passed_bookrating" />                  <edittext                     android:layout_width="match_parent"                     android:layout_height="wrap_content"                     android:id="@+id/passed_bookshelf" />             </linearlayout>         </linearlayout>     </linearlayout>      <linearlayout         android:orientation="horizontal"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/linearlayout5"         android:layout_alignparentstart="true"         android:id="@+id/linearlayout6">          <button             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/btn_update"             android:id="@+id/button_update"             android:onclick="updatebookinfo"/>          <button             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:text="@string/btn_delete"             android:id="@+id/btn_delete_book"             android:onclick="deletebook"/>     </linearlayout>      <linearlayout         android:orientation="horizontal"         android:layout_width="match_parent"         android:layout_height="wrap_content"         android:layout_below="@+id/linearlayout6">          <edittext             android:layout_width="wrap_content"             android:layout_height="wrap_content"             android:id="@+id/secret_edittext_title" />     </linearlayout> </relativelayout> 

with of @0x0nosugar (thanks that) found solution:

to updatebookinfo: added:

intent intent = new intent(getapplicationcontext(), bookdatalistactivity.class); startactivity(intent); 

and deleting:

    public void deletedata(){     btn_delete_book.setonclicklistener(new view.onclicklistener() {         @override         public void onclick(view v) {             integer deletedrows = bookdbhelper.deletedate(passedbooktitle.gettext().tostring());             if (deletedrows > 0) {                 toast.maketext(getapplicationcontext(), " book deleted", toast.length_long).show();                 intent intent = new intent(getapplicationcontext(), bookdatalistactivity.class);                 startactivity(intent);                 finish();             } else {                 toast.maketext(getapplicationcontext(), " book not deleted", toast.length_long).show();             }         }      }); 

at bookdbhelper:

    public integer deletedate (string book_title){     sqlitedatabase sqlitedatabase = this.getwritabledatabase();     string selection = bookcontent.newbookinfo.book_title+ " = ?";     string[] selection_args = {book_title};     return sqlitedatabase.delete(bookcontent.newbookinfo.table_name_books,selection, selection_args); } 

method @ list activitiy:

    @override public void onresume(){     super.onresume();     booklistdataadapter.notifydatasetchanged();  }