类似于刮奖的小功能,废话不多说直接上代码
-(UILabel*)textLbl{
if (_textLbl==nil ) {
_textLbl=[[UILabel alloc]init];
_textLbl.text=@"谢谢惠顾!";
_textLbl.frame=CGRectMake(100, 200, 200, 100);
_textLbl.textAlignment=NSTextAlignmentCenter;
}
return _textLbl;
}
-(UIImageView *)coatingImg{
if (_coatingImg==nil) {
_coatingImg=[[UIImageView alloc]init];
_coatingImg.image=[UIImage imageNamed:@"photo.jpg"];
_coatingImg.frame=self.textLbl.frame;
}
return _coatingImg;
}
- (void)touchesMoved:(NSSet*)touches withEvent:(nullable UIEvent *)event{
// 触摸任意位置
UITouch *touch = touches.anyObject;
// 触摸位置在图片上的坐标
CGPoint cententPoint = [touch locationInView:self.coatingImg];
// 设置清除点的大小
CGRect rect = CGRectMake(cententPoint.x, cententPoint.y, 20, 20);
// 默认是去创建一个透明的视图
UIGraphicsBeginImageContextWithOptions(self.coatingImg.bounds.size, NO, 0);
// 获取上下文(画板)
CGContextRef ref = UIGraphicsGetCurrentContext();
// 把imageView的layer映射到上下文中
[self.coatingImg.layer renderInContext:ref];
// 清除划过的区域
CGContextClearRect(ref, rect);
// 获取图片
UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
// 结束图片的画板, (意味着图片在上下文中消失)
UIGraphicsEndImageContext();
self.coatingImg.image = image;
}