如何从所选行的NSArray访问int？

Question

Sorry if the title sounds confusing. But I'm trying to make an app that has a table view. Each row has its own button with its own set of points. I pretty much want the button to add the specific amount of points to a counter. However, I don't know how to access an int of an NSArray of the selected row. Here is the code:

@interface FBViewController ()

@end

@implementation FBViewController {

    NSArray *tablePoints;
    NSArray *tablePointLabel;
    int counter;

}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    //A table that displays the points on the buttons
    tablePointLabel = [NSArray arrayWithObjects:
                   @"10",
                   @"10",
                   @"10",
                   @"20",
                   @"20",
                   @"20",
                   @"30",
                   @"30",
                   @"50",
                   @"70",
                   @"100",
                   @"300",
                   @"300",
                   nil];

    //table of ints (points)
    tablePoints = [NSArray arrayWithObjects:
                   @10,
                   @10,
                   @10,
                   @20,
                   @20,
                   @20,
                   @30,
                   @30,
                   @50,
                   @70,
                   @100,
                   @300,
                   @300,
                   nil];

    counter = 0;

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {

    return [tableData count];
}

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

    static NSString *simpleTableIdentifier = @"FBCell";

    FBCell *cell = (FBCell *)[tableView dequeueReusableCellWithIdentifier:simpleTableIdentifier];

    if (cell == nil) {
        NSArray *nib = [[NSBundle mainBundle] loadNibNamed:@"FBCell" owner:self options:nil];
        cell = [nib objectAtIndex:0];
    }


    UIButton *pointButton = [UIButton buttonWithType:UIButtonTypeRoundedRect];
    pointButton.frame = CGRectMake(250.0f, 5.0f, 75.0f, 30.0f);
    [pointButton setBackgroundColor:[UIColor greenColor]];
    [pointButton setTitle:[tablePointLabel objectAtIndex:indexPath.row] forState:UIControlStateNormal];
    [cell addSubview:pointButton];
    [pointButton addTarget:self
                    action:@selector(addPoint:)
              forControlEvents:UIControlEventTouchUpInside];


    return cell;
}

-(IBAction)addPoint:(id)sender {


    counter + [tablePoints objectAtIndex:indexPath.row] = counter; 
    **//This is where I have an issue. indexPath.row does not work for int arrays. what do i do???**


}

Answer 1

A NSArray holds objects, not values. In your case it holds NSNumber objects which in turn holds the values.

Use the indexPath.row to get the NSNumber and then get the value.

NSNumber *numberObject = [tablePoints objectAtIndex:myIndex];
int myInt = [numberObject intValue]; // NSNumber covers a range of different types of values

One question is where you're obtaining your indexPath.row and is it valid at that point.

Answer 2

Lots of ways to improve this (including suggestions offered by rmaddy)

My recommendation is instead of instantiating a uibutton (that I'm guessing is equal to the height/width of each table row, is to implement

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
//increments counte
counter += [tablePoints[indexPath.row] intValue];
}

Moreover, for the row label, just stick in uilabel, and for (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath, set the label according to the array value. In fact, you don't even need to declare two identical arrays, just repurpose the same one.