在UITableView List segue之间传递索引号

Question

当我单击UITableView中的某个列表项时,我想将我单击的项的索引传递给下一个详细视图.

到目前为止,这是我的相关代码:

 - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    HomeworkDetails *view =  [[HomeworkDetails alloc] init];


    int lastIndex = [indexPath indexAtPosition:[indexPath length] - 1];
    NSLog(@"%u", lastIndex);

    [self performSegueWithIdentifier: @"HomeworkDetailsSegue" sender:self];
    view.currentIndex = lastIndex;

    [tableView deselectRowAtIndexPath:indexPath animated:YES];

}

此时,我可以成功转到下一个ViewController(HomeworkDetails),但信息不会通过.我试图通过这样做来实现这一目标,view.currentIndex = lastIndex;但这不起作用.我怎么能这样做？对不起,如果我错过了什么 我是iOS开发的初学者.

建议:

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


    HomeworkDetails *view =  [[HomeworkDetails alloc] init];


    int lastIndex = [indexPath indexAtPosition:[indexPath length] - 1];
    NSLog(@"%u", lastIndex);

    [self performSegueWithIdentifier: @"HomeworkDetailsSegue" sender:self];
    view.currentIndex = lastIndex;

    [tableView deselectRowAtIndexPath:indexPath animated:YES];



}


- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"HomeworkDetailsSegue"]) {

        // note that "sender" will be the tableView cell that was selected
        UITableViewCell *cell = (UITableViewCell*)sender;
       NSIndexPath *indexPath = [self.tableView indexPathForCell:cell]; //**error**


        HomeworkDetails *vc = (HomeworkDetails*)[segue destinationViewController];
        vc.currentIndex = indexPath.row;
    }
}

Answer 1

您所描述的内容最好在prepareForSegue:sender:方法中完成,而不是didSelectRowAtIndexPath:.在故事板中,确保HomeworkDetailsSegue在tableView的原型单元格和目标视图控制器之间设置segue.

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{    
    if ([segue.identifier isEqualToString:@"HomeworkDetailsSegue"]) {

        // note that "sender" will be the tableView cell that was selected
        UITableViewCell *cell = (UITableViewCell*)sender;
        NSIndexPath *indexPath = [self.tableView indexPathForCell:cell];

        HomeworkDetails *vc = (HomeworkDetails*)[segue destinationViewController];
        vc.currentIndex = indexPath.row;
    }
}

另外,作为一种风格,我建议将HomeworkDetails类重命名为HomeworkDetailsViewController.这样做会更紧密地遵循Apple的惯例,并使其更清楚地表示类所代表的内容.