如何使用SubView的SuperView初始化UIView

Question

I have a UILabel that is the subview of a UIView, I would like to know how to use this UILabel to cast a new temporary UIView so that I can access its values and or its superview.

to explain my object I have a UIScrollView which contains a UIView which in turn contains a UILabel, I would like to know how I can access the UIScrollView attributes when all I have access to is the UILabel.

This is how I created the object

UIScrollView *containerScrollView = [[UIScrollView alloc] initWithFrame:CGRectMake(0.0, 0.0, self.view.frame.size.width, 77.0)];
insertView = [[UIView alloc] init];
    insertView.frame = CGRectMake(0.0, 0.0, scrollWidth+10, 77.0);
myLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 5.0, 40.0, 40.0];

[insertView addSubView:myLabel];
[containerScrollView addSubView:insertView];

Then I have a method that I am using to detect the new touch, add a value into the UILabel then check to see if the next UILabel is in frame or not. if it isn't then I am going to hopefully write some code to move the UIScrollViews scroll position.

this is that method

- (void) SymbolButtonPressed:(NSString *)selectedString {

    UILabel *label = (UILabel *)[self.view viewWithTag:currentlySelectedTag];

    if ([selectedString isEqualToString:@"Blank"]) {
        [label setText:@" "];
        [cutFieldsMutableArray replaceObjectAtIndex:currentlySelectedTag-1 withObject:@" "]; //replace first string with second string in the array

    } else {
        NSRange slashRange = [selectedString rangeOfString:@"/"];
        if (slashRange.location != NSNotFound) {
            NSString *updatedString = [[selectedString substringToIndex:slashRange.location] stringByAppendingString:@"+"];

            [label setText:updatedString];
            [cutFieldsMutableArray replaceObjectAtIndex:currentlySelectedTag-1 withObject:updatedString]; //replace first string with second string in the array

        } else {
            [label setText:selectedString];
            [cutFieldsMutableArray replaceObjectAtIndex:currentlySelectedTag-1 withObject:selectedString]; //replace first string with second string in the arrayg
        }
    }

    currentlySelectedTag ++;
    if (totalCutCount < currentlySelectedTag) {
        currentlySelectedTag = 1;
    }
    // reset tags so that you can set the correctly
    totalCount = 0; // zero this out so that the next time the view is loaded you can get an accurate count of cuts
    labelTag = 1;
    labelPositionTag = 1001;

    [self.tableView reloadData];


    // test code to see if I can access the UIScrollView to move its scroll position using the Label object I cast at the start of this method
    // this code is not working.
    UIScrollView *temptemp = ((UIScrollView *)label.superview.superview); // this equals nil

    // Sort out new position
    float newPosition = ((UIScrollView *)label.superview.superview).contentOffset.x+label.superview.superview.frame.size.width;
    CGRect toVisible = CGRectMake(newPosition, 0, label.superview.superview.frame.size.width, label.superview.superview.frame.size.height);
    // perform scroll to new position
    [(UIScrollView *)label.superview.superview scrollRectToVisible:toVisible animated:YES];

}

I have also tried print a output of the view hierarchy to see if using .superview.superview is correct and this is a copy and paste of the selected object/view

***UPDATE

<UIScrollView: 0x1676d560; frame = (0 0; 320 77); clipsToBounds = YES; gestureRecognizers = <NSArray: 0x16636b20>; layer = <CALayer: 0x16659970>; contentOffset: {0, 0}>
   |    |    |    |    |    |    |    | <UIView: 0x16637280; frame = (0 0; 404 18); layer = <CALayer: 0x16643980>>
   |    |    |    |    |    |    |    | <UIView: 0x16655da0; frame = (0 0; 414 77); layer = <CALayer: 0x16643950>>
   |    |    |    |    |    |    |    |    | <UILabel: 0x166ce3b0; frame = (2 35; 40 40); text = ' '; clipsToBounds = YES; tag = 1; gestureRecognizers = <NSArray: 0x166cf650>; layer = <CALayer: 0x16645dc0>>

which I am now wondering if the cast of the label in my symbolButtonPressed method dose not allow access to superviews?

Answer 1

The simple way would be:

UILabel *label = ... // the reference to your label
UIScrollView *scrollView = (UIScrollView *)label.superview.superview.superview;

This code assumes a fixed hierarchy of your views. There are safer ways to walk up a view's superviews until you find the proper parent view.