在plist iphone中访问数组内的字符串

Question

I have a plist with root of type dictionary containing keys of type array, and each array has three items of type string.

I want to access the strings and pass them to a view controller.

This line is successful in my cellForRowAtIndexPath

NSLog(@"Strings from plist: %@", [[self.aDictionary objectForKey:(@"%@",[self.keys objectAtIndex:row])] objectAtIndex:0]);

When I put the same line in my didSelectRowAtIndexPath method I get a BAD_ACCESS error.

Any suggestions as to how to get at the strings would be helpful.

Here is my .plist

<dict>
    <key>Derivative</key>
    <array>
        <string>Derivative 1</string>
        <string>front.png</string>
        <string>back.png</string>
    </array>
    <key>Rolle&apos;s Theorem</key>
    <array>
        <string>Rolle&apos;s Theorem 1</string>
        <string>front.png</string>
        <string>3bk.png</string>
    </array>
    <key>Chain Rule</key>
    <array>
        <string>Chain Rule</string>
        <string>chainrule1.png</string>
        <string>chainrule1_bk.png</string>
    </array>
</dict>
</plist>

And here are the two methods:

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }


    NSUInteger row = [indexPath row];

    cell.backgroundColor = [UIColor purpleColor];
    cell.textLabel.textColor = [UIColor blackColor];

    cell.textLabel.text = [self.keys objectAtIndex:row];

    // Key output to NSLOG accessing elements from the plist
    NSLog(@"Strings from plist: %@", [[self.aDictionary objectForKey:(@"%@",[self.keys objectAtIndex:row])] objectAtIndex:0]);

    cell.textLabel.font = [UIFont fontWithName:@"Verdana-Bold" size:18.0];
    cell.textLabel.numberOfLines = 2;
    cell.selectedBackgroundView = [[[UIImageView alloc] initWithImage:[UIImage imageNamed:@"TableCell_BG.png"]] autorelease];

    return cell;
}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

    NSUInteger row = [indexPath row];
    NSLog(@"Row selected was: %i", row);

    // Key output to NSLOG accessing elements from the plist
    //NSLog(@"Strings from plist: %@", [[self.aDictionary objectForKey:(@"%@",[self.keys objectAtIndex:row])] objectAtIndex:0]);


/*
    NSString *selectedCard = [[aDictionary objectForKey:(@"%@",[keys objectAtIndex:row])] objectAtIndex:0];
    NSLog(@"Showing Flash Card: %@", selectedCard);
*/

    FlashCardViewController *flashVC = [[FlashCardViewController alloc] initWithNibName:@"FlashCardViewController" bundle:nil];

    id aKey = [keys objectAtIndex:row];

    flashVC.aSelectedCard = [[aDictionary objectForKey:aKey] objectAtIndex:0];

    [self.navigationController pushViewController:flashVC animated:YES];
    [flashVC release];

}

Answer 1

My guess is that you are not retaining aDictionary or keys , or you have another memory problem that is manifesting at that point in the code. But it's difficult to tell without the rest of the code.

Answer 2

Change this line to

flashVC.aSelectedCard = [[aDictionary objectForKey:[keys objectAtIndex:row]] objectAtIndex:0];

Where does the program crash, what line?