UITableView 多对勾选择 [英] UITableView Multiple Checkmark Selection

问题描述

阅读了几个与此相关的问题后，我可以使该功能正常工作.然而，我的列表很长而且可以滚动，所以当我向上和向下滚动时，复选标记的选择到处都是.selectedIndexes 是一个 NSMutableArray.有什么想法吗?

Having read a couple of the questions asked relating to this, I can get the functionality to work. However my list is long and scrollable, so when I scroll up and down the selection of the checkmarks are all over the place. selectedIndexes is a NSMutableArray. Any ideas?

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

    if ([selectedCell accessoryType] == UITableViewCellAccessoryNone) {
        [selectedCell setAccessoryType:UITableViewCellAccessoryCheckmark];
        [selectedIndexes addObject:[NSNumber numberWithInt:indexPath.row]];

    } 
    else {
        [selectedCell setAccessoryType:UITableViewCellAccessoryNone];
        [selectedIndexes removeObject:[NSNumber numberWithInt:indexPath.row]];

    }

    [tableView deselectRowAtIndexPath:indexPath animated:NO];

}

在我的 cellForRowAtIndexPath: 中，我有以下检查.

In my cellForRowAtIndexPath: i have the following check.

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

    static NSString *CellIdentifier = @"CustomCell";

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

    // Configure the cell...
    NSDictionary *dictionary = [natures objectAtIndex:indexPath.section];
    NSArray *array = [dictionary objectForKey:@"Name"];
    NSString *cellValue = [array objectAtIndex:indexPath.row];
    cell.textLabel.text = cellValue;

    for (int i = 0; i < selectedIndexes.count; i++) {
        NSUInteger num = [[selectedIndexes objectAtIndex:i] intValue];

        if (num == indexPath.row) {
            [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
        }
        else {
            [cell setAccessoryType:UITableViewCellAccessoryNone];
        }

    }

    return cell;
}

推荐答案

您需要将您的 cellForRowAtIndexPath 修改为以下内容:

You need to modify your cellForRowAtIndexPath to be the following:

// Assume cell is not checked -- if it is the loop below will check it.
[cell setAccessoryType:UITableViewCellAccessoryNone];
for (int i = 0; i < selectedIndexes.count; i++) {
        NSUInteger num = [[selectedIndexes objectAtIndex:i] intValue];

        if (num == indexPath.row) {
            [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
            // Once we find a match there is no point continuing the loop
            break;
        }
    }

您需要这样做，因为可重复使用的单元格可能设置了复选标记——因此您需要清除它.希望这会有所帮助.

You need to do this because a reusable cell might have the checkmark set -- so you need to clear it. Hope this helps.

顺便说一句，使用 NSSet 可能是一个更优雅的解决方案！

Incidentally, using an NSSet would probably be a more elegant solution!

这篇关于UITableView 多对勾选择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！