If 语句基于之前的视图控制器是什么

Question

这是我到目前为止所做的：

- (void) tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{
    UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];
    if (preivousViewController isEqualToString:@"...") 
    {
        if ([self.filteredArray count] == 0)
            self.person = self.users[indexPath.row];
        else
            self.person = self.filteredArray[indexPath.row];
        self.mugshot = cell.imageView.image;

        [self performSegueWithIdentifier:@"SelectPerson" sender:self];
    } else {
        if ([self.filteredArray count] == 0)
            self.person = self.users[indexPath.row];
        else
            self.person = self.filteredArray[indexPath.row];
        self.mugshot = cell.imageView.image;

        [self performSegueWithIdentifier:@"selectVisitee" sender:self];
    }
}

它看起来很乱，这就是我试图修复它的原因（previousViewController 部分只是为了向您展示我想尝试做的事情）。

我想说的是：如果您是通过此转场或从名称为 suchandsuch 的视图控制器到达此视图的方式，则执行此转场或那个转场。有什么办法可以做到吗？

Answer 1

您可以从导航控制器检查堆栈的前一个 ViewController。

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

           if ([self.filteredArray count] == 0)
                self.person = self.users[indexPath.row];
            else
                self.person = self.filteredArray[indexPath.row];
            self.mugshot = cell.imageView.image;

            //Not the viewcontroller name string. Use the ViewController class name
            if ([self backViewController] == YOURVIEWCONTROLLER) 
           {

            [self performSegueWithIdentifier:@"SelectPerson" sender:self];

        } else {

        [self performSegueWithIdentifier:@"selectVisitee" sender:self];

        }
}

使用下面的方法，

- (UIViewController *)backViewController
{
    NSInteger numberOfViewControllers = self.navigationController.viewControllers.count;

    if (numberOfViewControllers < 2)
        return nil;
    else
        return [self.navigationController.viewControllers objectAtIndex:numberOfViewControllers - 2];
}

If 语句基于之前的视图控制器是什么

If statement based on whatever the previous view controller was

objective-c

viewcontroller

ios

uistoryboard

segue