一次只允许一个UITableViewCellAccessoryCheckmark

如何解决一次只允许一个UITableViewCellAccessoryCheckmark

|| 我有一个带有部分视图的表格视图，该部分包含用户可以“拾取”的声音列表。只有当前选择的声音应该显示“ 0”。基本上我可以正常工作。但是，例如底部的单元格被选中，然后向上滚动表格视图（使选中的单元格不可见），然后我检查另一个单元格，底部（不可见）单元格的检查未被删除。有人知道为什么吗？

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static Nsstring *CellIdentifier = @\"Cell\";
    static Nsstring *TheOtherone = @\"OtherCell\";
    static Nsstring *MiddleCell = @\"MiddleCell\";



    // Configure the cell...

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    Nsstring *theSound = [prefs objectForKey:@\"pickedFailSound\"];
    NSUInteger index = [failSounds indexOfObject:theSound];


    if (indexPath.section == 0){

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
        }


        failAtLaunch = [[[UISwitch alloc] initWithFrame:CGRectMake(200,7,100,30)] autorelease];
        [cell addSubview:failAtLaunch]; 
        cell.accessoryView = failAtLaunch; 
        cell.selectionStyle = UITableViewCellSelectionStyleNone;

        NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

        if(![prefs boolForKey:@\"failAtLaunch\"]) {
            [failAtLaunch seton:NO animated:NO];
        } else {
            [failAtLaunch seton:YES animated:NO];
        }

        [(UISwitch *)cell.accessoryView addTarget:self action:@selector(setIt) forControlEvents:UIControlEventValueChanged];
        cell.textLabel.text = @\"Instafail\";
        cell.detailTextLabel.text = @\"Fail at Laucnh\";

        return cell;

    } else if (indexPath.section == 1) {

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MiddleCell];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:MiddleCell] autorelease];
        }

        Nsstring *cellTitle = [failSounds objectAtIndex:indexPath.row];
        cell.textLabel.text = cellTitle;

        if (indexPath.row == index) {
            cell.accessoryType = UITableViewCellAccessorycheckmark;
        }



        if ([cellTitle isEqualToString:@\"Your Fail Sound\"]){

            NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
            if(![prefs boolForKey:@\"customSoundAvailable\"]) {

                cell.selectionStyle = UITableViewCellSelectionStyleNone;
                cell.userInteractionEnabled = NO;
                cell.textLabel.textColor = [UIColor grayColor];
                cell.detailTextLabel.text = @\"Record a Custom Failsound First\";
            }
        } 

    return cell;

    } else {

        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:TheOtherone];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero reuseIdentifier:TheOtherone] autorelease];
        }


       cell.textLabel.text = @\"Hold to record fail sound\";
        UIButton *btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
        btn.frame = CGRectMake(230.0f,4.0f,60.0f,36.0f);
        [btn setTitle:@\"OK\" forState:UIControlStatenormal];
        [btn setTitle:@\"OK\" forState:UIControlStateSelected];
        [btn addTarget:self action:@selector(recordAudio) forControlEvents:UIControlEventTouchDown];
        [btn addTarget:self action:@selector(stop) forControlEvents:UIControlEventTouchUpInside];
        [cell.contentView addSubview:btn];


       return cell; 

      }     
    }

和：

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


    [tableView deselectRowAtIndexPath:indexPath animated:YES];

    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    Nsstring *theSound = [prefs objectForKey:@\"pickedFailSound\"];
    NSUInteger index = [failSounds indexOfObject:theSound];

    //NSLog(@\"The index is: %@\",index);

    if (indexPath.section == 1){


                NSIndexPath *oldindexPath = [NSIndexPath indexPathForRow:index inSection:1];

                NSLog(@\"Oldindexpath is: %@\",oldindexPath);
                UITableViewCell *newCell = [tableView cellForRowAtIndexPath:indexPath];


                if (newCell.accessoryType == UITableViewCellAccessoryNone) {

                    newCell.accessoryType = UITableViewCellAccessorycheckmark;
                }

                UITableViewCell *oldCell = [tableView cellForRowAtIndexPath:oldindexPath];


                if (oldCell != newCell){

                    if (oldCell.accessoryType == UITableViewCellAccessorycheckmark) {

                        oldCell.accessoryType = UITableViewCellAccessoryNone;
                    } 
                }



    Nsstring *pickedSound = [failSounds objectAtIndex:indexPath.row];
    NSLog(@\"Picked sound is %@\",pickedSound);
    [prefs setobject:pickedSound forKey:@\"pickedFailSound\"];
    [prefs synchronize];        

    [self performSelector:@selector(loadSound) withObject:nil];
    [failSound play];



    }

}

    

解决方法

您不记得要为出队单元格重置附件类型。 这应该为您解决；

  cell.accessoryType = UITableViewCellAccessoryNone;

  if (indexPath.row == index) {
            cell.accessoryType = UITableViewCellAccessoryCheckmark;
  }

实用提示：您可能会发现使用switch（indexPath.section）而不是很多if ... elseif ... else构造很有用。尽管您现在只需要2个部分就可以了，但是我发现使用switch可以更轻松地扩展部分的数量，并且从心理上更容易阅读代码，因为您经常将if .. else结构用于其他事物-使用不同的语法有助于更清楚地说明测试的目的。     ,在每次声明

cell

之后的ѭ4中，尝试通过添加以下行来重置单元格类型：

cell.accessoryType = UITableViewCellAccessoryNone;