Sort a NSMutableArray of UIView according to their frame.origin.y

Question

I would like to sort an NSMutableArray of UIViews according to their frame.origin.y, I want the lowest view with y to be first etc. It can be the case that 2 UIViews have the same origin. Is there an existing method for this?

Answer 1

NSMutableArray has several sorting methods. Pick one of them, implement the sorting selector, block or function and compare the y values. Here is an example using blocks:

NSComparator comparatorBlock = ^(UIView *obj1, UIView *obj2) {
    if (obj1.frame.origin.y > obj2.frame.origin.y) {
        return (NSComparisonResult)NSOrderedDescending;
    }

    if (obj1.frame.origin.y < obj2.frame.origin.y) {
        return (NSComparisonResult)NSOrderedAscending;
    }
    return (NSComparisonResult)NSOrderedSame;
};

[array sortUsingComparator:comparatorBlock];

Answer 2

虽然这不是frame.origin.y，但您也可以使用SortDescriptor并将layer.position.y作为键来完成此操作。

[array sortedArrayUsingDescriptors:@[[[NSSortDescriptor alloc] initWithKey:@"layer.position.y" ascending:YES]]];

Answer 3

This is how you would do this in Swift:

listOfViews.sortInPlace { CGRectGetMinY($0.frame) < CGRectGetMinY($1.frame) }

Thats all :-) All my love to Swift :-)

Answer 4

you can get the array of subviews using

yourView.subviews

then you can iterate through each and check each frame.origin.y and do your coding