UITableView 点击取消选择单元格

Question

I have a UITableViewCell that is selected when tapped. During this selected state, if the user taps the cell again, I want the cell to deselect.

I can't find any of the delegate calls being hit. Any ideas how to implement this? Is it really going to be a gesture recognizer?

Answer 1

You can actually do this using the delegate method willSelectRowAtIndexPath:

- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    if ([cell isSelected]) {
        // Deselect manually.
        [tableView.delegate tableView:tableView willDeselectRowAtIndexPath:indexPath];
        [tableView deselectRowAtIndexPath:indexPath animated:YES];
        [tableView.delegate tableView:tableView didDeselectRowAtIndexPath:indexPath];

        return nil;
    }

    return indexPath;
}

Note that deselectRowAtIndexPath: won't call the delegate methods automatically, so you need to make those calls manually.

Answer 2

in Swift 4:

func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {

    if let indexPathForSelectedRow = tableView.indexPathForSelectedRow,
        indexPathForSelectedRow == indexPath {
        tableView.deselectRow(at: indexPath, animated: false)
        return nil
    }
    return indexPath
}

Answer 3

When using "Multiple Selection" mode, "didSelectRowAtIndexPath" will not be called when you click a row that is already selected. More than one row can still be selected programatically in "Single Selection" mode and the rows will trigger didSelectRowAtIndexPath on all clicks.

Just a heads up to anyone who was having the same problems.

Answer 4

Here is an even cleaner solution:

- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([[tableView indexPathForSelectedRow] isEqual:indexPath]) {
        [tableView deselectRowAtIndexPath:indexPath animated:YES];
        return nil;
    }
    return indexPath;
}

Answer 5

Leave the single selection mode on, but override the following funcs like this:

override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
    if tableView.indexPathsForSelectedRows?.contains(indexPath) ?? false {
       tableView.deselectRow(at: indexPath, animated: true)
       return nil
    }

    return indexPath
}

override func tableView(_ tableView: UITableView, willDeselectRowAt indexPath: IndexPath) -> IndexPath? {
    return nil
}

Answer 6

When you select a cell this delegate method is triggered.

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


        UITableViewCell *theUITableViewCell = [tableView cellForRowAtIndexPath:path];
        if (theUITableViewCell.selected == YES){
            self.tableView deselectRowAtIndexPath:<#(NSIndexPath *)#> animated:<#(BOOL)#>
            // Do more thing
        }else{
            // By default, it is highlighted for selected state
        }

 }

It's pseudo code.

Answer 7

I think that using the blue selection colouring for toggling may give a strange impression. Why not use an accessory like a checkmark? This is a much more familiar technique for selection toggling (be it multi-cell or single-cell).

See this answer for info: UITableView Multiple Selection

Answer 8

- (NSIndexPath *)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    if ([cell isSelected]) {
        // Deselect manually.
        if ([tableView.delegate respondsToSelector:@selector(tableView:willDeselectRowAtIndexPath:)]) {
            [tableView.delegate tableView:tableView willDeselectRowAtIndexPath:indexPath];
        }
        [tableView deselectRowAtIndexPath:indexPath animated:YES];
        if ([tableView.delegate respondsToSelector:@selector(tableView:didDeselectRowAtIndexPath:)]) {
            [tableView.delegate tableView:tableView didDeselectRowAtIndexPath:indexPath];
        }
        return nil;
    }

    return indexPath;
}

Answer 9

You can try this one, it's works for me (for single selection or multiple selections):

A. allocate a private NSMutableArray in viewDidLoad like:

@interface XXXViewController : UIViewController <UITableViewDataSource, UITableViewDelegate>
{
    NSMutableArray * selectedZoneCellIndexPaths;
}


- (void)viewDidLoad
{
    selectedZoneCellIndexPaths = [[NSMutableArray alloc] init];
}

B. in UITableViewDelegate didSelectRow add following lines

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

     for (NSIndexPath * iter in selectedZoneCellIndexPaths)
     {
         if (indexPath.section == iter.section && indexPath.row == iter.row)
         {
             [tableView deselectRowAtIndexPath:indexPath animated:YES];
             [selectedZoneCellIndexPaths removeObject:iter];
             return;
         }
     }
     [selectedZoneCellIndexPaths addObject:indexPath];
     return;
}

Answer 10

Swift version of prisonerjohn's answer :

public func tableView(tableView: UITableView, willSelectRowAtIndexPath indexPath: NSIndexPath) -> NSIndexPath? {
  let cell = tableView.cellForRowAtIndexPath(indexPath)
  if (cell?.selected ?? false) {
    // Deselect manually.
    tableView.delegate!.tableView?(tableView, willDeselectRowAtIndexPath: indexPath)
    tableView.deselectRowAtIndexPath(indexPath, animated: true)
    tableView.delegate!.tableView?(tableView, didDeselectRowAtIndexPath: indexPath)
    return nil
  }
return indexPath;
}

Answer 11

From @prisonerjohn, in case someone wonders how to check if the delegate responds to the selector as @Patrick said, in Swift 3 :

override func tableView(_ tableView: UITableView, willSelectRowAt indexPath: IndexPath) -> IndexPath? {
    guard let cell = tableView.cellForRow(at: indexPath) else {
        // Handle invalid cell
        ...
    }

    if cell.isSelected {
        if let respond = tableView.delegate?.responds(
            to: #selector(tableView(_:willDeselectRowAt:))),
            respond == true {
            tableView.delegate?.tableView!(tableView, willDeselectRowAt: indexPath)
        }

        tableView.deselectRow(at: indexPath, animated: true)

        if let respond = tableView.delegate?.responds(
            to: #selector(tableView(_:didDeselectRowAt:))),
            respond == true {
            tableView.delegate?.tableView!(tableView, didDeselectRowAt: indexPath)
        }

        return nil
    }

    return indexPath
}

Answer 12

Swift 5.

In the UITableViewDelegate , it's as simple as follows:

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    tableView.deselectRow(at: indexPath, animated: true)
}

Answer 13

I was after the same thing but @occulus' answer provided me the hint I was missing.

It made me realize the way to get this done is to allow multiple selection in the table view and manually deselect previously selected rows when a new row is selected using one of the delegate methods.

It seems quite natural that in single selection mode, the table view tries to leave one row selected as much as possible, thus not deselecting on tapping a selected row.

Answer 14

Maybe my question wasn't specific enough, but the two answers are a bit wide of what I was after.

It seems this isn't possible, and I went with a gesture recognizer of the cell to manually set selected / unselected state.