IOS8 UIImagePickerController 拍照自动旋转的问题

　　在IOS开发中，当我们需要拍照时，自然是弹出一个UIImagePickerController，并且设置sourceType=UIImagePickerControllerSourceTypeCamera。

然后再代理方法中用 UIImage *img=info[UIImagePickerControllerOriginalImage]来获取拍摄的图像，然后显示在界面或者转换成JPG上传到服务器

NSData *imgdata=UIImageJPEGRepresentation(fiximg, 0.75)（如果是PNG可能没问题）。

　　以前一直这么用，没有发现问题，可最近安装了XCODE6使用IOS8SDK的时候，发现上传通过以上方法上传的图片居然自动旋转了！！在IOS设备和MAC电脑

上显示是正常的，可是到了安卓设备或者windows确是逆时针旋转90度的照片。通过网上搜索，找到下面这个方法解决这个问题。新建一个UIImage Category.

.h文件

@interface UIImage (fixOrientation)
- (UIImage *)fixOrientation;
@end

 .m文件

#import "UIImage+fixOrientation.h"

@implementation UIImage (fixOrientation)

- (UIImage *)fixOrientation {
    
    // No-op if the orientation is already correct
    if (self.imageOrientation == UIImageOrientationUp) return self;
    
    // We need to calculate the proper transformation to make the image upright.
    // We do it in 2 steps: Rotate if Left/Right/Down, and then flip if Mirrored.
    CGAffineTransform transform = CGAffineTransformIdentity;
    
    switch (self.imageOrientation) {
        case UIImageOrientationDown:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, self.size.height);
            transform = CGAffineTransformRotate(transform, M_PI);
            break;
            
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, 0);
            transform = CGAffineTransformRotate(transform, M_PI_2);
            break;
            
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
    }
    
    switch (self.imageOrientation) {
        case UIImageOrientationUpMirrored:
        case UIImageOrientationDownMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.width, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
            
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRightMirrored:
            transform = CGAffineTransformTranslate(transform, self.size.height, 0);
            transform = CGAffineTransformScale(transform, -1, 1);
            break;
    }
    
    // Now we draw the underlying CGImage into a new context, applying the transform
    // calculated above.
    CGContextRef ctx = CGBitmapContextCreate(NULL, self.size.width, self.size.height,
                                             CGImageGetBitsPerComponent(self.CGImage), 0,
                                             CGImageGetColorSpace(self.CGImage),
                                             CGImageGetBitmapInfo(self.CGImage));
    CGContextConcatCTM(ctx, transform);
    switch (self.imageOrientation) {
        case UIImageOrientationLeft:
        case UIImageOrientationLeftMirrored:
        case UIImageOrientationRight:
        case UIImageOrientationRightMirrored:
            // Grr...
            CGContextDrawImage(ctx, CGRectMake(0,0,self.size.height,self.size.width), self.CGImage);
            break;
            
        default:
            CGContextDrawImage(ctx, CGRectMake(0,0,self.size.width,self.size.height), self.CGImage);
            break;
    }
    
    // And now we just create a new UIImage from the drawing context
    CGImageRef cgimg = CGBitmapContextCreateImage(ctx);
    UIImage *img = [UIImage imageWithCGImage:cgimg];
    CGContextRelease(ctx);
    CGImageRelease(cgimg);
    return img;
}

@end

 调用方式：

 　　   UIImage *img=info[UIImagePickerControllerOriginalImage];

    　　UIImage *fiximg=[img fixOrientation];