在objective-c中使用UITouchEvent填充颜色

@interface CustomView : UIView

@property (nonatomic, strong) UIColor *fillColor;

@end

@implementation CustomView

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    // 获取触摸点
    UITouch *touch = [touches anyObject];
    CGPoint touchPoint = [touch locationInView:self];
    
    // 设置填充颜色
    self.fillColor = [UIColor redColor];
    
    // 重新绘制视图
    [self setNeedsDisplay];
}

- (void)drawRect:(CGRect)rect {
    // 获取绘图上下文
    CGContextRef context = UIGraphicsGetCurrentContext();
    
    // 设置填充颜色
    [self.fillColor setFill];
    
    // 绘制填充矩形
    CGContextFillRect(context, rect);
}

@end

CustomView *customView = [[CustomView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
[self.view addSubview:customView];