iphone table view check mark accessory problem - iphone

Question

I have a table with 50 rows. I want to select particular rows with checkmark accessory but when i select some rows and scroll down the table then i see pre checked rows. I know that table cell are reused but i want to emit this problem what can i do about this?
- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return 1;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
// return [array count];
return 50;
}
// Customize the appearance of table view cells.
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text=[NSString stringWithFormat:#"%i",[indexPath row]];
return cell;
}
// Override to support row selection in the table view.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
if (cell.accessoryType == UITableViewCellAccessoryNone) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}

Answer 1

You have to set cell.accessoryType in - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
The fact is that as you have a reuse identifier, when a new cell is requested, a cell with the identifier is copied. As you have set the checkmark in the latest cell, the checkmask is copied.
You have to store the state of each cell (ie in an array) to recreate the cell with the right value.
Something like that:
BOOL values[50]; //Not the best way, but easy for the example...
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *CellIdentifier = #"Cell";
TableViewCell *cell = (TableViewCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
if (cell == nil) {
cell = [[[TableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
}
cell.textLabel.text=[NSString stringWithFormat:#"%i",[indexPath row]];
if (value[indexPath.row]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
values[indexPath.row] = !value[indexPath.row];
if (value[indexPath.row]) {
cell.accessoryType = UITableViewCellAccessoryCheckmark;
} else {
cell.accessoryType = UITableViewCellAccessoryNone;
}
}

Answer 2

You can do it with the help of array ,take one array and each array hold a dict do this condition in array
NSMutableArray *arr = [[NSMutableArray alloc]init];
for(int i=1; i<=50;i++)
{
NSmutableDictionary *dict = [[NSMutableDictionary alloc]init];
[dict setobject:[nsstring stringwithformat:#"%d",i] valueForkey:#"ID"];
[arr addobject:dict];
[dict release];
}
now rows is [arr count];
and put this check in cell appearance
NSMutabledict *dict1 = [arr objectatindex:indexpath.row];
if([[dict objectforkey:"Check"]==nil])
{
[dict setobject:[nsstring stringwithformate:#"1"] valueforkey:#"Check"];
}else
{
if([[dict objectforkey:"Check"] isequaltostring:#"1"]
{
cell.accessoryType = UITableViewCellAccessoryNone;
}
else
{
cell.accessoryType = UITableViewCellAccessoryCheckmark;
}
}
now put below code in didselect methood
nsmutabledict *dict1 = [arr objectatindex:indexpath.row];
if([[dict objectforkey:"Check"] isequaltostring:#"1"]
{
[dict setobject:[nsstring stringwithformate:#"2"] valueforkey:#"Check"];
}
else
{
[dict setobject:[nsstring stringwithformate:#"1"] valueforkey:#"Check"];
}