iOS 给View添加网格线

- (void)addGrid:(UIView *)view {
    CGFloat widthView = view.frame.size.width;
    CGFloat heightView = view.frame.size.height;
    CGFloat size = 50;
    
    void (^addLineWidthRect)(CGRect rect) = ^(CGRect rect) {
        CALayer *layer = [[CALayer alloc] init];
        [view.layer addSublayer:layer];
        layer.frame = rect;
        layer.backgroundColor = [[UIColor redColor] CGColor];
    };
    
    for (int i=0; i<widthView; i+=size) {
        addLineWidthRect(CGRectMake(i, 0, 1, heightView));
    }
    for (int i=0; i<heightView; i+=size) {
        addLineWidthRect(CGRectMake(0, i, widthView, 1));
    }
}