带复选标记的 UITableViewCell，复制复选标记 [英] UITableViewCell with Checkmark, duplicating checkmarks

问题描述

到目前为止在 Stack Overflow 上搜索我还没有找到像我这样的情况.非常感谢任何帮助:我一直看到，如果我在 A 上打勾，H 也会有一个，以及大约 10 外的一个人.基本上每 10 次它就会重复一个复选标记.

So far search on Stack Overflow I havent found a situation that is like mine. Any assistance is greatly appreciated: I keep seeing that if I put a checkmark on Person A, Person H will also have one as well as does a person about 10 away. Basically abut every 10 it repeats a check mark.

这是我的代码:

 - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{static NSString *CellIdentifier = @"MyCell";

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

             }

cell.textLabel.text = 

[NSString  stringWithFormat:@"%@ %@", [[myArrayOfAddressBooks objectAtIndex:indexPath.row] objectForKey:@"FirstName"],[[myArrayOfAddressBooks objectAtIndex:indexPath.row] objectForKey:@"LastName"]];
cell.detailTextLabel.text = 

[NSString  stringWithFormat:@"%@", [[myArrayOfAddressBooks objectAtIndex:indexPath.row] objectForKey:@"Address"]];

return cell;

}

在我为索引路径选择的行中，我有这个:

In my did select row for index path I have this:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
UITableViewCell *cell;
cell = [self.tableView cellForRowAtIndexPath: indexPath];

if ([[myArrayOfAddressBooks objectAtIndex:indexPath.row] objectForKey:@"emailSelected"] != @"YES")
{    
cell.accessoryType = UITableViewCellAccessoryCheckmark;
[[myArrayOfAddressBooks objectAtIndex:indexPath.row] setValue:@"YES" forKey:@"emailSelected"];
}
else
{    
    cell.accessoryType = UITableViewCellAccessoryNone;
    [[myArrayOfAddressBooks objectAtIndex:indexPath.row] setValue:@"NO" forKey:@"emailSelected"];
}     

推荐答案

这是由于 UITableView 如何回收" UITableViewCell 以提高效率，以及您如何标记选中的单元格.

This is due to how UITableView "recycles" UITableViewCell for efficiency purposes, and how you are marking your cells when they are selected.

您需要为您在 tableView:cellForRowAtIndexPath: 中处理/创建的每个单元格刷新/设置 accessoryType 值.您正确更新 myArrayOfAddressBooks 数据结构中的状态，您只需要在 tableView:cellForRowAtIndexPath:

You need to refresh/set the accessoryType value for every cell you process/create within tableView:cellForRowAtIndexPath:. You properly update the state in your myArrayOfAddressBooks data structure, and you just need to use this information in tableView:cellForRowAtIndexPath:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath

{
    static NSString *CellIdentifier = @"MyCell";

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

    NSDictionary *info = [myArrayOfAddressBooks objectAtIndex:indexPath.row];

    cell.textLabel.text = [NSString  stringWithFormat:@"%@ %@", [info objectForKey:@"FirstName"],[info objectForKey:@"LastName"]];
    cell.detailTextLabel.text = [NSString  stringWithFormat:@"%@", [info objectForKey:@"Address"]];

    cell.accessoryType = ([[info objectForKey:@"emailSelected"] isEqualString:@"YES"]) ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;

    return cell;
}

此外，除非有充分的理由将状态保存为 @"Yes" 或 @"No" 字符串，为什么不将它们保存为 [NSNumber numberWithBool:YES] 还是 [NSNumber numberWithBool:NO]?当您想要进行比较而不是一直使用 isEqualToString: 时，这将简化您的逻辑.

Also, unless there is a good reason for saving the state as @"Yes" or @"No" strings, why not save them as [NSNumber numberWithBool:YES] or [NSNumber numberWithBool:NO]? This will simplify your logic when you want to do comparisons versus having to use isEqualToString: all the time.

例如

    cell.accessoryType = ([[info objectForKey:@"emailSelected"] boolValue]) ? UITableViewCellAccessoryCheckmark : UITableViewCellAccessoryNone;

这篇关于带复选标记的 UITableViewCell，复制复选标记的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！