iPhone：UITableView CellAccessory复选标记

Question

In iPhone App on click of table view cell I want to display Table view cell Accessory type Check mark for that on didSelectRowAtIndexPath i am writing code

if(indexPath.row ==0)
{
[tableView cellForRowAtIndexPath:indexPath].accessoryType=UITableViewCellAccessoryCheckmark;
 }

and displaying check marks.

but in my case i wnt to allow user to check only on cell at a time means if user select other row then that row should checked and previously checked should be unchecked

How can I achieve that?

Answer 1

Keep track, in an instance variable, of which row is checked. When the user selects a new row, first uncheck the previously checked row, then check the new row and update the instance variable.

Here is more detail. First add a property to keep track of the currently checked row. It's easiest if this is an NSIndexPath .

@interface RootViewController : UITableViewController {
    ...
    NSIndexPath* checkedIndexPath;
    ...
}

...
@property (nonatomic, retain) NSIndexPath* checkedIndexPath;
...

@end

In your cellForRowAtIndexPath add the following:

if([self.checkedIndexPath isEqual:indexPath])
{
    cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
else 
{
    cell.accessoryType = UITableViewCellAccessoryNone;
}

How you code your tableView:didSelectRowAtIndexPath: will depend on the behavior you want. If there always must be a row checked, that is, that if the user clicks on an already checked row use the following:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    // Uncheck the previous checked row
    if(self.checkedIndexPath)
    {
        UITableViewCell* uncheckCell = [tableView
                     cellForRowAtIndexPath:self.checkedIndexPath];
        uncheckCell.accessoryType = UITableViewCellAccessoryNone;
    }
    UITableViewCell* cell = [tableView cellForRowAtIndexPath:indexPath];
    cell.accessoryType = UITableViewCellAccessoryCheckmark;
    self.checkedIndexPath = indexPath;
}

If you want to allow the user to be able to uncheck the row by clicking on it again use this code:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    // Uncheck the previous checked row
    if(self.checkedIndexPath)
    {
        UITableViewCell* uncheckCell = [tableView
                    cellForRowAtIndexPath:self.checkedIndexPath];
        uncheckCell.accessoryType = UITableViewCellAccessoryNone;
    }
    if([self.checkedIndexPath isEqual:indexPath])
    {
        self.checkedIndexPath = nil;
    }
    else
    {
        UITableViewCell* cell = [tableView cellForRowAtIndexPath:indexPath];
        cell.accessoryType = UITableViewCellAccessoryCheckmark;
        self.checkedIndexPath = indexPath;
    }
}

Answer 2

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *newCell =[tableView cellForRowAtIndexPath:indexPath];
int newRow = [indexPath row];
int oldRow = [lastIndexPath row];
if (newRow != oldRow)
{
    newCell = [tableView  cellForRowAtIndexPath:indexPath];
    newCell.accessoryType = UITableViewCellAccessoryCheckmark;
    UITableViewCell *oldCell = [tableView cellForRowAtIndexPath: lastIndexPath]; 
    oldCell.accessoryType = UITableViewCellAccessoryNone;
    lastIndexPath = indexPath;  
}
}

For reference take a look at this discussion

Answer 3

this is a simple solution that worked for me:

in your .h file declare:

NSIndexPath *checkedCell;

then in your .m file add:

        if (checkedCell == indexPath) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
        } else { 
cell.accessoryType = UITableViewCellAccessoryNone; 
}

to the cellForRowAtIndexPath method and

checkedCell = indexPath;
[tableView reloadData]

to the didSelectRowAtIndexPath method.

Best of luck!

Answer 4

I worked on your problem and got a solution

in .h file

int rowNO;
    NSIndexPath *lastIndexPth;

in . m file

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    NSLog(@"%d",indexPath.row);
    if (rowNO!=indexPath.row) {
        rowNO=indexPath.row;        
        [tableView cellForRowAtIndexPath:indexPath].accessoryType=UITableViewCellAccessoryCheckmark;
        [tableView cellForRowAtIndexPath:lastIndexPth].accessoryType=UITableViewCellAccessoryNone;
        lastIndexPth=indexPath;
    }

I hope this might help you...

Answer 5

its simple

in .h

NSIndexPath   checkedCell;

In .m

cellForRowAtIndexPath


if ([checkedCell isEqual:indexPath]) 

{
    cell.accessoryType = UITableViewCellAccessoryCheckmark;


} else
{ 
    cell.accessoryType = UITableViewCellAccessoryNone; 
}

in didSelectRowAtIndexPath

checkedCell = indexPath;

[tableView reloadData]

Answer 6

I hope this one solves your problem :

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

int newRow = [indexPath row];
int oldRow = (lastIndexPath != nil) ? [lastIndexPath row] : -1;

if (newRow != oldRow)
{
    UITableViewCell *newCell = [tableView cellForRowAtIndexPath:
                                indexPath];
    newCell.accessoryType = UITableViewCellAccessoryCheckmark;

    UITableViewCell *oldCell = [tableView cellForRowAtIndexPath: 
                                lastIndexPath]; 
    oldCell.accessoryType = UITableViewCellAccessoryNone;
    lastIndexPath = indexPath;
}

[tableView deselectRowAtIndexPath:indexPath animated:YES];
}

Answer 7

You could store NSIndexPath of the checked row as the class variable, whenever you try to the others row just access the previously checked row using the NSIndexPath variable stored as class variable and unchecked that.

Check the below post

http://www.iphonedevsdk.com/forum/iphone-sdk-development/24240-uitableviewcellaccessorycheckmark-one-checkmark-time.html

Answer 8

Add to your UITableViewDataSource delegate variable NSIndexPath *checkedIndex . Add to didSelectRowAtIndexPath:

checkedIndex = indexPath;
[tableView reload];

And change your cellForRowAtIndexPath: method:

cell = .. // init or dequeue
if ([indexPath isEqualTo:checkedIndex])
{
    cell.accessoryType=UITableViewCellAccessoryCheckmark;
}
else
{
    cell.accessoryType=UITableViewCellAccessoryNone;
}