如何在iOS，Objective C的tableview中的每个部分中仅实现单个单元格选择

Question

我有一个包含 5 个部分的表格视图，并且我已将表格视图选择设置为多个。每个部分都有不同的行数。我想要设置用户只能从每个部分中选择一个单元格（在我的表格中，用户可以选择任意数量的单元格）。 例如：5 个部分的 5 个单元格。

应该不可能从任何部分选择多个单元格。如果用户从同一部分选择另一个单元格，则应取消选择先前选择的单元格。我怎样才能做到这一点。这是 didSelectRowAtIndexPath 的示例实现。

- (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);

    }

}

Answer 1

您需要跟踪单元格的选择。所以你需要将选定的indexpath 存储在数组中。

在ViewController.h 中声明这样的属性

@property(nonatomic,strong) NSMutableDictionary *selectionData;

现在在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);

}

您的numberOfRowsInSection、numberOfSectionsInTableView 和titleForHeaderInSection 将保持不变。

如果您有任何疑问，请告诉我。

Answer 2

您可以在界面生成器中设置表格视图的selection 属性。在 IB 中选择您的 tableview，然后选择attribute inspector and setsingle selectiontoselection` 属性，如下图所示。

或者您可以通过编程方式设置，

 self.tableView.allowsMultipleSelection = NO;

更新：

如果您希望每个部分单选，那么您可以实现willSelectRowAtIndexPath，如下所示，

 - (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 ;
}

在这种情况下，我认为您应该允许在tableview 中进行多项选择。

参考：Answer of John Sauer

Answer 3

看起来您正在更新表选择时的 celltwo / cellone selectedsignLabel.hidden。所以@Lion 解决方案将不起作用。您必须使用以下代码保存最后选择的索引：

@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 ;
}

我还没有更新完整的工作代码。但这是实现的方法。您也可以使用 userdefault 代替 self.selectedIndexPathDict。