iOS关于截屏的几种代码

/** *截图功能 */-(void)screenShot{    UIGraphicsBeginImageContextWithOptions(CGSizeMake(640, 960), YES, 0);    //设置截屏大小    [[self.view layer] renderInContext:UIGraphicsGetCurrentContext()];    UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();    CGImageRef imageRef = viewImage.CGImage;    CGRect rect = CGRectMake(0, 0, 641, SCREEN_HEIGHT + 300);//这里可以设置想要截图的区域    CGImageRef imageRefRect =CGImageCreateWithImageInRect(imageRef, rect);    UIImage *sendImage = [[UIImage alloc] initWithCGImage:imageRefRect];     //以下为图片保存代码    UIImageWriteToSavedPhotosAlbum(sendImage, nil, nil, nil);//保存图片到照片库    NSData *imageViewData = UIImagePNGRepresentation(sendImage);    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);    NSString *documentsDirectory = [paths objectAtIndex:0];    NSString *pictureName= @"screenShow.png";    NSString *savedImagePath = [documentsDirectory stringByAppendingPathComponent:pictureName];    [imageViewData writeToFile:savedImagePath atomically:YES];//保存照片到沙盒目录    CGImageRelease(imageRefRect);
//从手机本地加载图片    UIImage *bgImage2 = [[UIImage alloc]initWithContentsOfFile:savedImagePath];    }

/** *截图 */- (void)screenShot{    UIImage* image = nil;    UIGraphicsBeginImageContext(m_scrollView.contentSize);    {        CGPoint savedContentOffset = m_scrollView.contentOffset;        CGRect savedFrame = m_scrollView.frame;        m_scrollView.contentOffset = CGPointZero;        m_scrollView.frame = CGRectMake(0, 0, m_scrollView.contentSize.width, m_scrollView.contentSize.height);        [m_scrollView.layer renderInContext: UIGraphicsGetCurrentContext()];        image = UIGraphicsGetImageFromCurrentImageContext();             m_scrollView.contentOffset = savedContentOffset;        m_scrollView.frame = savedFrame;    }    UIGraphicsEndImageContext();        if (image != nil) {        NSLog(@"截图成功!");    }}