重新使用表格单元格中的UI开关

Question

我在我的UITableViewCell中遇到了uiswitch问题，每当我在属于特定部分的特定单元格中更改开关值时。所有其他部分单元格具有相同的inexPath.row更改。请帮忙 ？

这里是我的cellForRowAtIndexPath方法的代码：

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath 
{ 
    static NSString *CellIdentifier = @"Cell"; 
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; 

    //UISwitch *switchview = nil ; 

    if (cell == nil) 
    { 
     cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
             reuseIdentifier:CellIdentifier]; 



    } 


    UISwitch *switchController = [[UISwitch alloc] initWithFrame:CGRectZero]; 
    CGRect switchFrame = switchController.frame; 
    NSString *str = [[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]; 
    NSLog(@"string in cell%@", str); 


    //set its x and y value, this you will have to determine how to space it on the left side 
    switchFrame.origin.x = 50.0f; 
    switchFrame.origin.y = 10.0f; 
    switchController.frame = switchFrame; 


    [switchController addTarget:self action:@selector(switchChanged:) forControlEvents:UIControlEventValueChanged]; 
    [cell addSubview:switchController ]; 
    [addSubview:switchController]; 


    if ([[[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row ]isEqualToString:@"ON"]) 
{ 
     switchController.on=YES; 
} 
    else 
    { 
     switchController.on=NO; 
    } 


    return cell; 

} 

这里是SwitchChangedEvent：

-(void)switchChanged:(UISwitch *)sender 
{ 
    UITableViewCell *cell = (UITableViewCell *)[sender superview]; 
    NSIndexPath *index=[mainTableView indexPathForCell:cell]; 

    if (sender.on) 
    { 

     [[self.SwitchArray objectAtIndex:index.section] replaceObjectAtIndex:index.row withObject:@"ON"]; 
     NSString *word= [[self.mainArray objectAtIndex:index.section ] objectAtIndex:index.row]; 

    } 
    else 
    { 
     //call the first array by section 
     [[self.SwitchArray objectAtIndex:index.section] replaceObjectAtIndex:index.row withObject:@"OFF"]; 
     NSString *word= [[self.mainArray objectAtIndex:index.section ] objectAtIndex:index.row]; 


    } 

    [padFactoids setObject:[NSKeyedArchiver archivedDataWithRootObject:SwitchArray] forKey:@"savedArray"]; 
    [padFactoids synchronize]; 

} 

Answer 1

如果你看看，我想你会发现你正在建立多个交换机和各细胞。

随着单元重新使用，您添加一个新开关但不删除旧单元。我认为这至少是你问题原因的一部分。

---

UPDATE

我想我会以不同方式处理这一点比其他人。我认为@AlanoudAldrees将更容易删除旧开关。

if (cell == nil) 
{ 
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
            reuseIdentifier:CellIdentifier]; 
} 
else 
{ 
    for (UIView *view in cell.subviews) 
     if ([view isKindOfClass:[UISwitch class]]) 
      [view removeFromSuperview]; 
} 

Answer 2

你有两个主要问题：

1. 这段代码是错误的：

   [cell addSubview:switchController ]; 
   

   绝不添加一个子视图到细胞;将其仅添加到单元的contentView。

2. 您每次都通过cellForRowAtIndexPath:添加开关。但是这些细胞正在被重复使用。所以有些单元已经有这个开关。因此，您正在向某些单元添加许多开关。

Answer 3

正如其他人已经指出的那样，您要为每个单元添加多个开关。 FTFY：

UISwitch *switchController = nil; 
if (cell == nil) 
{ 
    cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault 
            reuseIdentifier:CellIdentifier]; 
    switchController = [[UISwitch alloc] initWithFrame:CGRectZero]; 
    switchController.tag = 'swch'; 
    CGRect switchFrame = switchController.frame; 
    //set its x and y value, this you will have to determine how to space it on the left side 
    switchFrame.origin.x = 50.0f; 
    switchFrame.origin.y = 10.0f; 
    switchController.frame = switchFrame; 
    [switchController addTarget:self action:@selector(switchChanged:) forControlEvents:UIControlEventValueChanged]; 
    [cell.contentView addSubview:switchController]; 
} 
else 
{ 
    switchController = (UISwitch*)[cell.contentView viewWithTag: 'swch']; 
    NSAssert(switchController != nil, @"how?"); 
} 

NSString *str = [[self.SwitchArray objectAtIndex:indexPath.section] objectAtIndex:indexPath.row]; 
NSLog(@"string in cell%@", str); 

switchController.on = [str isEqualToString:@"ON"]; 

return cell;