问题
I have a table view with 5 sections and I have set the tableview selection to multiple. Each section have different number of rows. What I want is to set that the user can select only one cell from each section(in my table user can select any number of cells). ex: 5 cells from 5 sections.
It should be impossible to select more than one cell from any section. If user select another cell from same section, previously selected cell should be deselected. How can I do this. This is a sample implementation of didSelectRowAtIndexPath.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
HoteldetalcelloneTableViewCell *cellone = (HoteldetalcelloneTableViewCell *)[self.detailtableView cellForRowAtIndexPath:indexPath];
HoteldetailcelltwoTableViewCell *celltwo = (HoteldetailcelltwoTableViewCell *)[self.detailtableView cellForRowAtIndexPath:indexPath];
//I have implement for two sections to test.
if(indexPath.section == 0)
{
HotelDetailsone *secone = [roomonearray objectAtIndex:indexPath.row];
HoteldetailsforBooking *book = [HoteldetailsforBooking new];
if([secone.offerallow isEqualToString:@"True"])
{
celltwo.selectedsignLabel.hidden = NO;
}
else
{
cellone.selectedsignLabelone.hidden = NO;
}
// [self.detailtableView reloadData];
NSLog(@"price for room 1 : %@", secone.itempriceText);
}
else
{
HotelDetailsone *sectwo = [roomtwoarray objectAtIndex:indexPath.row];
HoteldetailsforBooking *book = [HoteldetailsforBooking new];
if([sectwo.offerallow isEqualToString:@"True"])
{
celltwo.selectedsignLabel.hidden = NO;
}
else
{
cellone.selectedsignLabelone.hidden = NO;
}
// [self.detailtableView reloadData];
NSLog(@"price for room 1 : %@", sectwo.itempriceText);
}
}
回答1:
You need to keep track on the selection of cell. So you need to store selected indexpath in array.
in ViewController.h declare property like this
@property(nonatomic,strong) NSMutableDictionary *selectionData;
Now in ViewController.m
- (void)viewDidLoad {
[super viewDidLoad];
self.selectionData=[[NSMutableDictionary alloc]init];
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
TestTableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"mycell"];
if ([self.selectionData objectForKey:[NSString stringWithFormat:@"%ld",(long)indexPath.section] ] != nil) {
NSMutableArray *sectionData=[[self.selectionData objectForKey:[NSString stringWithFormat:@"%ld",(long)indexPath.section]] mutableCopy];
if (![sectionData containsObject:[NSNumber numberWithLong:indexPath.row]])
{
cell.accessoryType = UITableViewCellAccessoryNone;
cell.numberlabel.text = @"2";
}
else
{
cell.numberlabel.text = @"***";
cell.accessoryType=UITableViewCellAccessoryCheckmark;
}
}
else
{
cell.numberlabel.text = @"2";
cell.accessoryType = UITableViewCellAccessoryNone;
}
cell.selectionStyle = UITableViewCellSelectionStyleNone;
return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
NSLog(@"selected section :%li ---> selected row :%li",(long)indexPath.section, (long)indexPath.row);
[self handleSelectionForSection:indexPath.section row:indexPath.row];
[self.tablev reloadData];
}
-(void)handleSelectionForSection:(long)sectionIndex row:(long)rowIndex
{
if ([self.selectionData objectForKey:[NSString stringWithFormat:@"%ld",sectionIndex] ] != nil) {
NSMutableArray *sectionData=[[self.selectionData objectForKey:[NSString stringWithFormat:@"%ld",sectionIndex]] mutableCopy];
if (![sectionData containsObject:[NSNumber numberWithLong:rowIndex]])
{
//removing previous selected rows
[sectionData removeAllObjects];
[sectionData addObject:[NSNumber numberWithLong:rowIndex]];
[self.selectionData setObject:sectionData forKey:[NSString stringWithFormat:@"%ld",sectionIndex]];
}
else
{
//cell you tapped is already selected,
// you can deselect it by removing object
//if you dont want to deselect it comment following lines
[sectionData removeObject:[NSNumber numberWithLong:rowIndex]];
[self.selectionData setObject:sectionData forKey:[NSString stringWithFormat:@"%ld",sectionIndex]];
}
}
else
{
//section key not available so we need to create it
NSMutableArray *sectionData=[[NSMutableArray alloc]init];
[sectionData addObject:[NSNumber numberWithLong:rowIndex]];
[self.selectionData setObject:sectionData forKey:[NSString stringWithFormat:@"%ld",sectionIndex]];
}
NSLog(@"All Selection : %@",self.selectionData);
}
Your numberOfRowsInSection, numberOfSectionsInTableView and titleForHeaderInSection will remain same.
Let me know if you have any query.
回答2:
You can set selection property of tableview from interface builder. Select your tableview in IB and then select attribute inspector and setsingle selectiontoselection` property like below screenshot.
Or you can set programattically,
self.tableView.allowsMultipleSelection = NO;
Update :
If you want single selection per section then you can implement willSelectRowAtIndexPath as below,
- (NSIndexPath*)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath*)indexPath {
for ( NSIndexPath* selectedIndexPath in tableView.indexPathsForSelectedRows ) {
if ( selectedIndexPath.section == indexPath.section )
[tableView deselectRowAtIndexPath:selectedIndexPath animated:NO] ;
}
return indexPath ;
}
In this case you should allow multiple selection in tableview i think.
Reference : Answer of John Sauer
回答3:
Looks like you are updating celltwo / cellone selectedsignLabel.hidden on table selection. so @Lion solution will not working. You have to save the last selected index using below code :
@property (nonatomic, strong) NSMutableDictionary *selectedIndexPathDict;
// in viewDidLoad:
self.tableView.allowsMultipleSelection = YES;
self.selectedIndexPathDict = [[NSMutableDictionary alloc] init];
//In table view delegate.
- (NSIndexPath*)tableView:(UITableView *)tableView willSelectRowAtIndexPath:(NSIndexPath*)indexPath {
NSString *indexSection = [NSString stringWithFormat:@"%ld", (long)indexPath.section];
NSIndexPath *indexPath1 = self.selectedIndexPathDict[indexSection];
if ( indexPath1) {
HotelDetailsone *secone = [roomonearray objectAtIndex:indexPath.row];
secone.offerallow ^= YES; //toggle bool value
// update new selected index path.
[self.selectedIndexPathDict setObject:indexPath forKey:indexSection];
//reload previous selected cell.
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(),^{
[tableView beginUpdates];
[tableView reloadRowsAtIndexPaths:@[indexPath1] withRowAnimation:UITableViewRowAnimationFade];
[tableView endUpdates];
});
} else {
//initialise selected index path
self.selectedIndexPathDict[indexSection] = indexPath;
}
[tableView deselectRowAtIndexPath:indexPath animated:NO] ;
return indexPath ;
}
I have not update the complete working code. But this is the way to achieve. You can also use the userdefault instead of self.selectedIndexPathDict.
来源：https://stackoverflow.com/questions/38221297/how-to-implement-only-single-cell-selection-in-each-section-in-the-tableview-in