UIPickerView中的多行选择

Question

我想在UIPickerView中选择多行,所以我有想法在表中显示我的数据并将该表作为子视图添加到选择器中.我试过这个,但没有成功.

有什么建议怎么做？

Answer 1

你可以在没有UITableView的情况下使用UITapGestureRecognizer :)

另外,NSMutableArray *selectedItems在.h文件中添加一些内容.

- (UIView *)pickerView:(UIPickerView *)pickerView viewForRow:(NSInteger)row forComponent:(NSInteger)component reusingView:(UIView *)view {
    UITableViewCell *cell = (UITableViewCell *)view;

    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:nil];
        [cell setBackgroundColor:[UIColor clearColor]];
        [cell setBounds: CGRectMake(0, 0, cell.frame.size.width -20 , 44)];
        UITapGestureRecognizer *singleTapGestureRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleSelection:)];
        singleTapGestureRecognizer.numberOfTapsRequired = 1;
        [cell addGestureRecognizer:singleTapGestureRecognizer];
    }

    if ([selectedItems indexOfObject:[NSNumber numberWithInt:row]] != NSNotFound) {
        [cell setAccessoryType:UITableViewCellAccessoryCheckmark];
    } else {
        [cell setAccessoryType:UITableViewCellAccessoryNone];
    }
    cell.textLabel.text = [datasource objectAtIndex:row];
    cell.tag = row;

    return cell;
}

- (void)toggleSelection:(UITapGestureRecognizer *)recognizer {
    NSNumber *row = [NSNumber numberWithInt:recognizer.view.tag];
    NSUInteger index = [selectedItems indexOfObject:row];
    if (index != NSNotFound) {
        [selectedItems removeObjectAtIndex:index];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryNone];
    } else {
        [selectedItems addObject:row];
        [(UITableViewCell *)(recognizer.view) setAccessoryType:UITableViewCellAccessoryCheckmark];
    }
}

Answer 2

在iPhone上进行多项选择的"接受"用户界面是使用带有复选标记的UITableView(即不要使用UIPickerView进行多项选择).

但是,如果你必须,有一些关于如何伪造它的说明http://www.iphonedevsdk.com/forum/iphone-sdk-development/14634-uipickerview-multiple-selection.html做一个空的选择器并放一个在它的顶部的表视图.

Answer 3

如果有人感兴趣的话,实现快速入侵以获取UIPickerView多选行为(如在Mobile Safari中)而不在pickerview前面添加其他视图:https://github.com/alexleutgoeb/ALPickerView

我们非常感谢您的改进!