iOS-indexPath 总是返回 nil

Question

我在触摸 TableView 时使用此方法获取 indexPath

-(NSIndexPath *)tableView:(UITableView *)tableView willDeselectRowAtIndexPath:(NSIndexPath *)indexPath{
    if (indexPath.row==0) {
        return nil;
    }else{
        return indexPath;
    }
}

我想将一个 NSString 传输到第二个 viewController，所以我的代码是这样的

-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{
    NSIndexPath *indexPath = [self.tableView indexPathForCell:sender];
    NSString *name =self.nameArray[indexPath.row];
    [segue.destinationViewController navigationItem].title = name;
    id theSegue = segue.destinationViewController;
    [theSegue setValue:name forKey:@"showName"];
    }

但 indexPath 始终为 nil，并且 -tableView:tableView willDeselectRowAtIndexPath indexPath 可能不会执行。

那我怎么才能在touch cell的时候得到正确的indexPath呢？谢谢。

Answer 1

试试下面的代码

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // set Segue Identifier from your first viewcontroller to second viewController in stoaryboard
    [self performSegueWithIdentifier:@"firstVCToSecondVCSegueIdentifier" sender:indexPath];
}

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{
    if ([segue.identifier isEqualToString:@"firstVCToSecondVCSegueIdentifier"])
    {
        if ([sender isKindOfClass:[NSIndexPath class]])
        {
            NSIndexPath *indexPath = (NSIndexPath *)sender;
            if ([segue.destinationViewController isKindOfClass:[SecondVC class]]) {
                SecondVC *aSecondVC = (SecondVC*)segue.destinationViewController;
                NSString *name =self.nameArray[indexPath.row];
                aSecondVC.title = name;
            }
        }
    }
}