getItemAtPosition（）如何从ListView中的选定项获取可读数据

Question

I have a listView of contacts that I got from the Android ContactManager sample. This list is showing up fine, but I can't figure out how to get info from the selected item, like "name" and "phone number".

I can get the selected position, but the result of the mContactList.getItemAtPosition(position) is a ContentResolver$CursorWrapperInner and that doesn't really make any sense to me. I can't get heads or tails from that.

Anyone know how I can get the name/id/phone number from the selected item in the listView?

Here is my code.

@Override
public void onCreate(Bundle savedInstanceState)
{
    Log.v(TAG, "Activity State: onCreate()");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.choose_contact);

    // Obtain handles to UI objects
    mAddAccountButton = (Button) findViewById(R.id.addContactButton);
    mContactList = (ListView) findViewById(R.id.contactList);
    mShowInvisibleControl = (CheckBox) findViewById(R.id.showInvisible);

    // Initialize class properties
    mShowInvisible = false;
    mShowInvisibleControl.setChecked(mShowInvisible);
    mContactList.setOnItemClickListener(new OnItemClickListener()
    {
      public void onItemClick(AdapterView<?> parent, View view, int position, long id)
      {
       addContactAt(position);
      }
    });
    mShowInvisibleControl.setOnCheckedChangeListener(new OnCheckedChangeListener() {
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.d(TAG, "mShowInvisibleControl changed: " + isChecked);
            mShowInvisible = isChecked;
            populateContactList();
        }
    });

    // Populate the contact list
    populateContactList();

}

/**
 * Populate the contact list based on account currently selected in the account spinner.
 */
private SimpleCursorAdapter adapter;
private void populateContactList() {
    // Build adapter with contact entries
    Cursor cursor = getContacts();
    String[] fields = new String[] {
            ContactsContract.Data.DISPLAY_NAME
    };
    adapter = new SimpleCursorAdapter(this, R.layout.contact_entry, cursor,
            fields, new int[] {R.id.contactEntryText});
    mContactList.setAdapter(adapter);
}

/**
 * Obtains the contact list for the currently selected account.
 *
 * @return A cursor for for accessing the contact list.
 */
private Cursor getContacts()
{
    // Run query
    Uri uri = ContactsContract.Contacts.CONTENT_URI;
    String[] projection = new String[] {
            ContactsContract.Contacts._ID,
            ContactsContract.Contacts.DISPLAY_NAME
    };
    String selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '" +
            (mShowInvisible ? "0" : "1") + "'";
    String[] selectionArgs = null;
    String sortOrder = ContactsContract.Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC";

    return managedQuery(uri, projection, selection, selectionArgs, sortOrder);
}

private void addContactAt(int position)
{
 Object o = mContactList.getItemAtPosition(position);
}

}`

Answer 1

@Override
protected void onListItemClick(ListView l, View v, int position, long ida) {
   super.onListItemClick(l, v, position, ida);

   Cursor mycursor = (Cursor) getListView().getItemAtPosition(position);
   showToast("mycursor.getString(1) " + mycursor.getString(1) +"   ");

Answer 2

BOOM!I figured it out. Basically you get the position number from the click event, then in my addContatAt() you use that position to search within the cursor for the field you want. In my case I wanted the display name.

I'm used to doing things in Flex, so this Cursor business is different for me :)

Anyways, for others here is my code:

@Override
public void onCreate(Bundle savedInstanceState)
{
    Log.v(TAG, "Activity State: onCreate()");
    super.onCreate(savedInstanceState);
    setContentView(R.layout.choose_contact);

    // Obtain handles to UI objects
    mAddAccountButton = (Button) findViewById(R.id.addContactButton);
    mContactList = (ListView) findViewById(R.id.contactList);
    mShowInvisibleControl = (CheckBox) findViewById(R.id.showInvisible);

    // Initialize class properties
    mShowInvisible = false;
    mShowInvisibleControl.setChecked(mShowInvisible);
    mContactList.setOnItemClickListener(new OnItemClickListener()
    {
         public void onItemClick(AdapterView<?> parent, View view, int position, long id)
         {
             addContactAt(position);
         }
    });
    mShowInvisibleControl.setOnCheckedChangeListener(new OnCheckedChangeListener() {
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            Log.d(TAG, "mShowInvisibleControl changed: " + isChecked);
            mShowInvisible = isChecked;
            populateContactList();
        }
    });

    // Populate the contact list
    populateContactList();

}

/**
 * Populate the contact list based on account currently selected in the account spinner.
 */
private SimpleCursorAdapter adapter;
private void populateContactList() {
    // Build adapter with contact entries
    contactsCursor = getContacts();
    String[] fields = new String[] {
            ContactsContract.Data.DISPLAY_NAME
    };
    adapter = new SimpleCursorAdapter(this, R.layout.contact_entry, contactsCursor,
            fields, new int[] {R.id.contactEntryText});
    mContactList.setAdapter(adapter);
}

/**
 * Obtains the contact list for the currently selected account.
 *
 * @return A cursor for for accessing the contact list.
 */
private Cursor getContacts()
{
    // Run query
    Uri uri = ContactsContract.Contacts.CONTENT_URI;
    String[] projection = new String[] {
            ContactsContract.Contacts._ID,
            ContactsContract.Contacts.DISPLAY_NAME
    };
    String selection = ContactsContract.Contacts.IN_VISIBLE_GROUP + " = '" +
            (mShowInvisible ? "0" : "1") + "'";
    String[] selectionArgs = null;
    String sortOrder = ContactsContract.Contacts.DISPLAY_NAME + " COLLATE LOCALIZED ASC";

    return managedQuery(uri, projection, selection, selectionArgs, sortOrder);
}

private void addContactAt(int position)
{
    contactsCursor.moveToPosition(position);
    String name = contactsCursor.getString(
            contactsCursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME));
}
}

Answer 3

public void onItemClick(AdapterView<?> parent, View view,int position, long id) 
{
Map<String, Object> map = (Map<String, Object>)_productListView.getItemAtPosition(position); 
String _productCode = (String) map.get("ProductCode");
String _productName = (String) map.get("ProjectName");
Double _price = (Double) map.get("Price");
}

Answer 4

Hmm - you're messing with your AdapterView's cursor behind its back, which may not always be a good idea. The alternative is to call parent.getItemAtPosition(position) inside your onItemClick handler and cast the result to a Cursor; it will be pointing at the row corresponding to the item that was clicked on.

Answer 5

I used the following code as mentioned by Miki Habryn

    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
    Cursor client = (Cursor)parent.getItemAtPosition(position);
    String client_name = client.getString(2); // third column in db
    Toast.makeText(getBaseContext(), client_name, Toast.LENGTH_SHORT).show();
}