根据headerView位置改变headerView颜色(collectionView/tableview)

滑动时,tableview中的headerView 的frame不断改变,collectionView的headerView的center不断改变.
so
tableview:

-(void)setFrame:(CGRect)frame{

    [super setFrame:frame];

    CGRect rect =  [self.superview convertRect:frame toView:[UIApplication sharedApplication].keyWindow];

    if (rect.origin.y > 65 && rect.size.height > 0 && ![self.backgroundColor isEqual:[UIColor whiteColor]]) {

        [self setBackgroundColor:[UIColor whiteColor]];

    }else if(rect.origin.y < 65 && rect.size.height > 0 && ![self.backgroundColor isEqual:UIColorFromRGB(0xff3333)]){

        [self setBackgroundColor:UIColorFromRGB(0xff3333)];

    }

}

collectionView:

#import "CollectionReusableView.h"

@interface CollectionReusableView(){

    CGFloat centerY;

}

@end

@implementation CollectionReusableView

-(void)setFrame:(CGRect)frame{

    [super setFrame:frame];

    centerY = self.frame.origin.y + self.frame.size.height/2.0;

}

-(void)setCenter:(CGPoint)center{

    [super setCenter:center];

    if (center.y < centerY + 1  && ![self.backgroundColor isEqual:[UIColor whiteColor]]) {

        [self setBackgroundColor:[UIColor whiteColor]];

    }else if(center.y > centerY + 1   > 0 && ![self.backgroundColor isEqual:[UIColor redColor]]){

        [self setBackgroundColor:[UIColor redColor]];

    }

}

@end