cornerRadius causes long load time in iOS 10 - ios

Question

I have a problem with my App. I have a View with 25 Buttons with changed cornerRadius. Since iOS 10 it takes about 5-6 seconds till this View loads.
Here is the relevant code:
- (void)setupTiles {
for (TileButton *btn in tiles_btn) {
btn.alpha = 0.0;
btn.layer.borderColor = [UIColor blackColor].CGColor;
btn.layer.borderWidth = 1.0f;
[btn layoutIfNeeded];
bin.layer.cornerRadius = btn.frame.size.width*0.3;
}
[self colorTilesWithArray:currentTileColors];
}
When i remove the following lines, is loads the view instantly:
[btn layoutIfNeeded];
bin.layer.cornerRadius = btn.frame.size.width*0.3;
The Buttons are grouped in an outlet collection, in case that's necessary to know.
Does anybody have a solution?
Thanks in advance!
Nico
Image 1: This takes about 5-6 seconds
Image 2: This is the View that will be loaded
TileButton.h-File:
#interface TileButton : UIButton
#property (nonatomic) int colorMode;
+ (UIColor *)blue;
+ (UIColor *)red;
+ (UIColor *)green;
+ (UIColor *)yellow;
+(UIColor *)colorForColorCode:(int)colorCode;
-(int)colorMode;
#end
TileButton.m-File:
#implementation TileButton
- (instancetype)init {
self = [super init];
if (self) {
self.layer.cornerRadius = self.frame.size.width*0.3;
}
return self;
}
+(UIColor *)blue {
return [UIColor colorWithRed:41.0/255.0 green:161.0/255.0 blue:255.0/255.0 alpha:1];
}
+(UIColor *)red {
return [UIColor colorWithRed:255.0/255.0 green:71.0/255.0 blue:109.0/255.0 alpha:1];
}
+(UIColor *)green {
return [UIColor colorWithRed:0.0/255.0 green:185.0/255.0 blue:30.0/255.0 alpha:1];
}
+(UIColor *)yellow {
return [UIColor colorWithRed:255.0/255.0 green:198.0/255.0 blue:26.0/255.0 alpha:1];
}
+(UIColor *)colorForColorCode:(int)colorCode {
switch (colorCode) {
case 1:
return [TileButton blue];
break;
case 2:
return [TileButton red];
break;
case 3:
return [TileButton green];
break;
case 4:
return [TileButton yellow];
break;
default:
return [UIColor blackColor];
break;
}
}
-(int)colorMode {
if (CGColorEqualToColor(self.backgroundColor.CGColor, [TileButton blue].CGColor))
return 1;
else if (CGColorEqualToColor(self.backgroundColor.CGColor, [TileButton red].CGColor))
return 2;
else if (CGColorEqualToColor(self.backgroundColor.CGColor, [TileButton green].CGColor))
return 3;
else if (CGColorEqualToColor(self.backgroundColor.CGColor, [TileButton yellow].CGColor))
return 4;
else
return -1;
}
#end

Answer 1

Since you are creating the buttons in Interface Builder you will need to set the cornerRadius in the awakeFromNib method. It should look something like this:
#implementation TileButton
-(void) awakeFromNib {
[super awakeFromNib];
self.layer.cornerRadius = self.frame.size.width*0.3;
}
https://developer.apple.com/reference/objectivec/nsobject/1402907-awakefromnib

Answer 2

Why can't you set the corner radius outside the for loop?
UIButton *btn = [UIButton alloc] initWithFrame:CGRectMake(0, 0, 0, 0)]; // set your frame here
bin.layer.cornerRadius = btn.frame.size.width*0.3; // width stays the same, set it here
for (TileButton *btn in tiles_btn) {
btn.alpha = 0.0;
btn.layer.borderColor = [UIColor blackColor].CGColor;
btn.layer.borderWidth = 1.0f;
// you need to set the button frame here
btn.frame = CGRectMake(0,0,0,0);
[btn layoutIfNeeded];
}
[self colorTilesWithArray:currentTileColors];

Answer 3

Assuming that TileButton is a subclass of UIButton, on initialization, you can set the TileButton to have your custom color, width, and corner radius. That way all of your buttons already have the specified customization on button creation.