在IBAction中获取indexPath.row？

Question

In my app there is a table view. When a row in the table view is selected a UIView appears and shows information. The row title comes from a plist file with strings in it. The plist file also includes strings with a phone number associated with the row title. In the custom UIView I have a button, when you click the button I want it to call the number which is declared in the plist file. The number which is associated with the row the user clicked.

How could I accomplish this?

The action is a ordinary IBAction:

- (IBAction)callNumber:(id)sender;

It is connected to the button in IB (in Xcode 4).

I would appreciate if someone had a solution to my problem, thanks.

Edit

For some clarity, I would like to get the phone number which is associated with the row you select in the table view. The string in the plist has a key, for the phone number name: "phone".

NSString *phone = [[tableList objectAtIndex:indexPath.row] objectForKey:@"phone"];

"tablelist" is a NSMutableArray. I would like to get the key "phone" and store it in the NSString *phone. All this in a IBAction. Would it help to post the whole class?

Answer 1

There is an elegant solution for this and it is when you setup the UITableViewCell . Set the tag of the UIButton to the index of the row:

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

    static NSString* CellIdentifier = @"Cell";

    YourCustomCell* cell = (YourCustomCell*)[tableView 
                              dequeueReusableCellWithIdentifier:CellIdentifier];

    //  All the code for loading a cell

    //  Other code you have for configuring the cell

    //  HERE'S THE IMPORTANT PART: SETTING THE
    //  BUTTON'S TAG TO THE INDEX OF THE ROW
    cell.phoneButton.tag = indexPath.row;

    return cell;    
}

Then, in the action code you can pull the index out of the tag:

- (IBAction)callNumber:(id)sender {
    UIButton* button = sender;
    int index = button.tag;
    NSString *phone = [[tableList objectAtIndex:indexPath.row] objectForKey:@"phone"];
    //  Make the phone call
}

Answer 2

You need to have a property on the "custom view" that indicates the index path of the row that was selected. You can put this in your custom view controller's header to declare this property:

@interface MyCustomViewController : UIViewController {
    ...
    NSIndexPath * indexPath;
}
@property (nonatomic, retain) NSIndexPath * indexPath;

Then, setup the implementation like this:

@implementation MyCustomViewController
@synthesize indexPath;
...
// only needed if not using ARC
- (void)dealloc {
    self.indexPath = nil;
    ...
    [super dealloc];
}
@end

Now, in the tableView:didSelectRowAtIndexPath: method, simply create the view controller as usual, but set the indexPath property on it so that it can be accessed in the future:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    MyCustomViewController * vc = [[MyCustomViewController alloc] initWithBundle:nil nibName:nil];
    [vc setIndexPath:indexPath];
    [self presentModalViewController:vc];
    // if not using ARC
    [vc release];
}

Then, anywhere in MyCustomViewController.m , simply write self.indexPath.row to get the row of the index path that was selected.

Answer 3

What you could do as a quick temporary workaround is the following:

Cell Selected Method: - save an NSUserDefault for what indexPath.row was selected

And in your next view: - read the NSUserDefault value for whichever row was read

This will then let the next view know which one was selected and allow you to get the proper data for it.

Answer 4

If you have controls in a UITableViewCell that perform actions where you need to know the index path there are a few methods you can use:

1. if you have a single section (or a known section for the cells with controls) and are not using the tag property for something else, store the row + 1 in the tag property. Then when the action is called, retrieve sender.tag - 1 and you've got your row index.

2. walk up the superview chain from your control until you get to the UITableViewCell . The call [tableView indexPathForCell:cell to get the indexPath.

3. create a subclass of your control and store the indexPath in the control.