iOS UITableViewCells rows recycled and tag not working

问题

I would like to seek some help in setting tag for buttons in cells. This is a question with a link to the previous I posted : iOS Using NSDictionary to load data into section and rows

However, though I could pass in data dynamically now, my renewal button on each of the rows could not seem to get the data and would only detect the same book title of each section when any of the rows in the section is selected.

Based on what I've read so far, it's because the button is being recycled hence, unable to detect which book is being selected properly. I've tried to set tag:

cell.renewButton.tag = indexPath.row;

How my code looks like now:

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

static NSString *CellIdentifier = @"Cell";
UserCustomCell *cell = (UserCustomCell *) [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
cell.bookTitle.frame = CGRectMake(12, 0, 550, 40);

if (cell == nil) {
    [[NSBundle mainBundle] loadNibNamed:@"UserCustomCell" owner:self options:nil];
    cell = userCustomCell;
    self.userCustomCell = nil;
    cell.renewButton.tag = indexPath.row;
}

if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad) {
    cell.bookTitle.frame = CGRectMake(12, 0, 550, 40);
    cell.renewButton.frame = CGRectMake(600, 14, 68, 24);
}
[cell.renewButton useBlackActionSheetStyle];

//########## EDIT STARTS HERE dataSource = [[NSMutableDictionary alloc] init]; // This would need to be an ivar

for (NSDictionary *rawItem in myArray) {
    NSString *date = [rawItem objectForKey:@"date"]; // Store in the dictionary using the data as the key

    NSMutableArray *section = [dataSource objectForKey:date]; // Grab the section that corresponds to the date

    if (!section) { // If there is no section then create one and add it to the dataSource
        section = [[NSMutableArray alloc] init];
        [dataSource setObject:section forKey:date];
    }

    [section addObject:rawItem]; // add your object
}
self.dataSource = dataSource;
//NSLog(@"Data Source Dictionary: %@", dataSource); 

NSArray *sections =[[dataSource allKeys] sortedArrayUsingSelector:@selector(caseInsensitiveCompare:)];
NSString *sectionTitle = [sections objectAtIndex:indexPath.section];

NSArray *items = [dataSource objectForKey:sectionTitle];

NSDictionary *dict = [items objectAtIndex:indexPath.row];
cell.bookTitle.text = [dict objectForKey:@"name"];
cell.detail.text = [NSString stringWithFormat:@"Due Date: %@ Due Time: %@", 
                    [dict objectForKey:@"date"], [dict objectForKey:@"time"]];


cell.renewButton.tag = indexPath.row;
return cell;

}

but it doesn't work at all. Would be sooooo grateful for any suggestions :) Thank you!!

P.S: My copy of xcode is not updated, only till version4. Saw some people mentioning storing of tag status in DataModel but it's only available in newer versions. :)

回答1:

I could not see your cell.renewButton being assigned a selector method (the method that should be triggered on tapping the button).

[cell.renewButton addTarget:self action:@selector(renewButtonPressed:) forControlEvents:UIControlEventTouchUpInside];

Also, I would specify a tag number with an offset, as tag of 0 is almost like not tagging at all. First row of tableView will give indexPath.row = 0.

Above your code,

#define OFFSET 100 /* Or any number greater than 0 */

In cellForRowAtIndexPath,

...
[cell.renewButton addTarget:self action:@selector(renewButtonPressed:) forControlEvents:UIControlEventTouchUpInside];
cell.renewbutton.tag = indexPath.row + OFFSET;
...

In the renewButtonPressed method,

-(void)renewButtonPressed:(id)sender
{
    tappedNum = [sender tag] - OFFSET;
    /* do your stuff */
}

tappedNum will give you the row that the button is tapped, starting with 0.

回答2:

You cannot use the button tags, as these will be the same as those of the cells they have been recycled from. Instead, use the indexPath to determine on which row you are and use that directly. No need to go through the button tag.

来源：https://stackoverflow.com/questions/11700121/ios-uitableviewcells-rows-recycled-and-tag-not-working

标签

ios

ios4

dynamic

uitableview