不确定将代码放在程序中的什么位置。在XCode中如何在触摸时生成圆。(Objective-C)

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface CircleGenerator : NSObject

- (UIView *)generateCircleAtPoint:(CGPoint)point withRadius:(CGFloat)radius;

@end

#import "CircleGenerator.h"

@implementation CircleGenerator

- (UIView *)generateCircleAtPoint:(CGPoint)point withRadius:(CGFloat)radius {
    CGRect frame = CGRectMake(point.x - radius, point.y - radius, 2 * radius, 2 * radius);
    UIView *circleView = [[UIView alloc] initWithFrame:frame];
    circleView.backgroundColor = [UIColor redColor];
    circleView.layer.cornerRadius = radius;
    return circleView;
}

@end

#import "ViewController.h"
#import "CircleGenerator.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // 其他初始化操作
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self.view];
    
    CircleGenerator *circleGenerator = [[CircleGenerator alloc] init];
    UIView *circleView = [circleGenerator generateCircleAtPoint:touchPoint withRadius:50.0];
    
    [self.view addSubview:circleView];
}

@end