IOS实现手动截图并保存

@property (weak, nonatomic) IBOutlet UIImageView *imageView;

@property (nonatomic, weak) UIView *clipView;

- (UIView *)clipView{  //如果clipView为被创建，就创建  if (_clipView == nil)  {    UIView *view = [[UIView alloc] init];    _clipView = view;    //设置clipView的背景色和透明度    view.backgroundColor = [UIColor blackColor];    view.alpha = 0.5;    //将clipView添加到控制器的view上，此时的clipView不会显示（未设置其frame）    [self.view addSubview:_clipView];  }  return _clipView;}

/**创建手势**/UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(pan:)];  /**  *每当pan手势的位置发生变化，就会调用pan:方法，并将手势作为参数传递  *//**添加手势**/[self.view addGestureRecognizer:pan];

@property (nonatomic, assign) CGPoint startPoint;

- (void)pan:(UIPanGestureRecognizer *)pan{  CGPoint endPoint = CGPointZero;  if (pan.state == UIGestureRecognizerStateBegan)  {    /**开始点击时，记录手势的起点**/    self.startPoint = [pan locationInView:self.view];  }  else if(pan.state == UIGestureRecognizerStateChanged)  {    /**当手势移动时，动态改变终点的值，并计算起点与终点之间的矩形区域**/    endPoint = [pan locationInView:self.view];    //计算矩形区域的宽高    CGFloat w = endPoint.x - self.startPoint.x;    CGFloat h = endPoint.y - self.startPoint.y;    //计算矩形区域的frame    CGRect clipRect = CGRectMake(self.startPoint.x, self.startPoint.y, w, h);    //设置剪切区域的frame    self.clipView.frame = clipRect;  }  else if(pan.state == UIGestureRecognizerStateEnded)  {    /**若手势停止，将剪切区域的图片内容绘制到图形上下文中**/    //开启位图上下文    UIGraphicsBeginImageContextWithOptions(self.imageView.bounds.size, NO, 0);    //创建大小等于剪切区域大小的封闭路径    UIBezierPath *path = [UIBezierPath bezierPathWithRect:self.clipView.frame];    //设置超出的内容不显示，    [path addClip];    //获取绘图上下文    CGContextRef context = UIGraphicsGetCurrentContext();    //将图片渲染的上下文中    [self.imageView.layer renderInContext:context];    //获取上下文中的图片    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();    //关闭位图上下文    UIGraphicsEndImageContext();    //移除剪切区域视图控件，并清空    [self.clipView removeFromSuperview];    self.clipView = nil;    //将图片显示到imageView上    self.imageView.image = image;    //通过alertView提示用户，是否将图片保存至相册    UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:@"保存图片" message:@"是否将图片保存至相册？" delegate:self cancelButtonTitle:@"否" otherButtonTitles:@"是", nil];    [alertView show];}}

- (void)alertView:(nonnull UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{  //若点击了“是”，则保存图片  if (buttonIndex == 1)  {    UIImageWriteToSavedPhotosAlbum(self.imageView.image, nil, nil, nil);    /**    * 该方法可以设置保存完毕调用的方法，此处未进行设置    */  }}