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POUsing listviews with a database
 

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  1. POUsing listviews with a database
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    <p>and good day. My project is having 2 activities, first one to insert data into the database which works well, but then I want to show a list view of the data within the database in another activity. </p> <p>I've tried local data eg fred, george in an array and the list view works great however, when I try to use the database. The activity crashes. It seems that I am unable to use "database.open"</p> <pre><code>public class MyListActivity extends Activity{ DatabaseAdapter database; //Creates item_details based on the ListItemDetails class ListItemDetails item_details; public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_list); //Uses the arraylist and set the result ArrayList&lt;ListItemDetails&gt; result = GetSearchResults(); ListView lv = (ListView)findViewById(R.id.listView1); lv.setAdapter(new CustomListAdapter(getApplicationContext(),result)); } private ArrayList&lt;ListItemDetails&gt; GetSearchResults() { ArrayList&lt;ListItemDetails&gt; results = new ArrayList&lt;ListItemDetails&gt;(); item_details = new ListItemDetails(); /* database.open(); Cursor c = database.getAllContacts(); if (c.moveToFirst()) { do { item_details.setFirstName(c.getString(1)); results.add(item_details); } while (c.moveToNext()); } */ return results; } } </code></pre> <p>Here is the main activity. The database opens fine when I use the buttonShow, so I tried buttonTest and storing them into the list but it got a bit confusing for me.</p> <pre><code>public class FamousPersonActivity extends Activity { EditText editFirstName, editLastName; Button buttonAdd, buttonShow, buttonTest; ListView lv; ListItemDetails item_details; DatabaseAdapter database; int request_Code = 1; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_famous_person); database = new DatabaseAdapter(this); lv = (ListView)findViewById(R.id.listView1); //ArrayList&lt;ListItemDetails&gt; result = GetSearchResults(); //lv.setAdapter(new CustomListAdapter(getApplicationContext(),result)); editFirstName = (EditText)findViewById(R.id.editFirstName); editLastName = (EditText)findViewById(R.id.editLastName); buttonAdd = (Button)findViewById(R.id.buttonAdd); buttonShow = (Button)findViewById(R.id.buttonShow); buttonTest = (Button)findViewById(R.id.buttonTest); buttonAdd.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { Toast.makeText(getApplicationContext(), "added to database", Toast.LENGTH_SHORT).show(); database.open(); long id = database.insertContact("Test Contact", "Test Email") ; database.close(); } }); buttonTest.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Intent i = new Intent("com.id11020260.exercise6part2.MyListActivity"); startActivityForResult(i, request_Code); } }); buttonShow.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View arg0) { try { String destPath = "/data/data/" + getPackageName() + "/databases"; File f = new File(destPath); if (!f.exists()) { f.mkdirs(); f.createNewFile(); //---copy the db from the assets folder into // the databases folder--- CopyDB(getBaseContext().getAssets().open("mydb"), new FileOutputStream(destPath + "/MyDB")); } } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } //---get all contacts--- database.open(); Cursor c = database.getAllContacts(); if (c.moveToFirst()) { do { DisplayContact(c); } while (c.moveToNext()); } database.close(); } }); } private ArrayList&lt;ListItemDetails&gt; GetSearchResults() { ArrayList&lt;ListItemDetails&gt; results = new ArrayList&lt;ListItemDetails&gt;(); item_details = new ListItemDetails(); database.open(); Cursor c = database.getAllContacts(); if (c.moveToFirst()) { do { item_details.setFirstName(c.getString(1)); results.add(item_details); } while (c.moveToNext()); database.close(); } return results; } public void CopyDB(InputStream inputStream, OutputStream outputStream) throws IOException { //---copy 1K bytes at a time--- byte[] buffer = new byte[1024]; int length; while ((length = inputStream.read(buffer)) &gt; 0) { outputStream.write(buffer, 0, length); } inputStream.close(); outputStream.close(); } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.famous_person, menu); return true; } public void DisplayContact(Cursor c) { Toast.makeText(this, "id: " + c.getString(0) + "\n" + "Name: " + c.getString(1) + "\n" + "Email: " + c.getString(2), Toast.LENGTH_LONG).show(); } } </code></pre> <p>This is the stack trace, I'm not sure if this is entirely correct</p> <p><img src="https://i.stack.imgur.com/hmJcC.png" alt="enter image description here"></p>
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USuser2663646
    1. USuser2663646
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    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
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      1. PTAnswer
    1. This table or related slice is empty.
    1. COGive stack trace too
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      1. POUsing listviews with a database
      1. USDavid Sainty
    2. COPlz post your database code.
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      1. POUsing listviews with a database
      1. USAsha Soman
    3. COpost logcat output please
      singulars
      1. POUsing listviews with a database
      1. USuser755
 

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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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