偶尔，当拍摄从相册或图片相机拍摄照片黑色解决问题的方法，解决问题和头部转动的方法

我尝试了很多方法，在线。无解！

其目的是相同的，它是基于图像的方向orientation 对于旋转相应的角度，达到我们想要的效果。！

的条形码直接观看，我曾是imagePickerController要获取的图片

#pragma mark - UIImagePickerControllerDelegate methods
//当选择一张图片后进入这里
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
    //照片的处理在这里
  //  NSString *type = [info objectForKey:UIImagePickerControllerMediaType];
//*
    UIImage *originalImage = [info objectForKey:UIImagePickerControllerOriginalImage];
    UIImageOrientation orientation = originalImage.imageOrientation;
    if (orientation == UIImageOrientationUp) {
        [self dismissViewControllerAnimated:YES completion:nil];
        _memberIconView.image = originalImage;
    }else if(orientation == UIImageOrientationRight){
        [self dismissViewControllerAnimated:YES completion:nil];
        _memberIconView.image = [originalImage imageRotatedByDegrees:90.0];
    }
}
 

这里我想说一下，在http://stackoverflow.com/上有人指出用这种方法就可以解决这个问题，但是我的问题还是存在！

stackoverflow上的方法例如以下：

-(UIImage *)fixOrientation
{
    if (self.imageOrientation == UIImageOrientationUp) {
        return self;
    }
    CGAffineTransform transform;
    NSLog(@"%i",self.imageOrientation);
    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:
        {
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        }
        case UIImageOrientationRightMirrored:
        {
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        }
        default:
            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;
    }
    
    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;
}

最后我综合了其它方法。一起来填充UIImage的类扩展，来终于解决这个问题：

方法：事实上他也是依据方向做出角度旋转，可是他管用

- (UIImage *)imageRotatedByRadians:(CGFloat)radians {
    return [self imageRotatedByDegrees:radiansToDegrees(radians)];
}
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees {
    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
    CGAffineTransform t = CGAffineTransformMakeRotation(degreesToRadians(degrees));
    rotatedViewBox.transform = t;
    CGSize rotatedSize = rotatedViewBox.frame.size;
    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();
    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
    // Rotate the image context
    CGContextRotateCTM(bitmap, degreesToRadians(degrees));
    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}

最后附上这个类扩展的全部源代码，直接粘贴复制就可以用：

先是头文件：UIImage+fixOrientation.h

#import <UIKit/UIKit.h>

@interface UIImage (fixOrientation)
- (UIImage *)fixOrientation;
- (UIImage *)imageRotatedByRadians:(CGFloat)radians;
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;

@end

再来.m文件：UIImage+fixOrientation.m

#import "UIImage+fixOrientation.h"

CGFloat degreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
CGFloat radiansToDegrees(CGFloat radians) {return radians * 180/M_PI;};
@implementation UIImage (fixOrientation)

-(UIImage *)fixOrientation
{
    if (self.imageOrientation == UIImageOrientationUp) {
        return self;
    }
    CGAffineTransform transform;
    NSLog(@"%i",self.imageOrientation);
    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:
        {
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        }
        case UIImageOrientationRightMirrored:
        {
            transform = CGAffineTransformTranslate(transform, 0, self.size.height);
            transform = CGAffineTransformRotate(transform, -M_PI_2);
            break;
        }
        default:
            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;
    }
    
    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;
}


- (UIImage *)imageRotatedByRadians:(CGFloat)radians {
    return [self imageRotatedByDegrees:radiansToDegrees(radians)];
}
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees {
    // calculate the size of the rotated view's containing box for our drawing space
    UIView *rotatedViewBox = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.size.width, self.size.height)];
    CGAffineTransform t = CGAffineTransformMakeRotation(degreesToRadians(degrees));
    rotatedViewBox.transform = t;
    CGSize rotatedSize = rotatedViewBox.frame.size;
    // Create the bitmap context
    UIGraphicsBeginImageContext(rotatedSize);
    CGContextRef bitmap = UIGraphicsGetCurrentContext();
    // Move the origin to the middle of the image so we will rotate and scale around the center.
    CGContextTranslateCTM(bitmap, rotatedSize.width/2, rotatedSize.height/2);
    // Rotate the image context
    CGContextRotateCTM(bitmap, degreesToRadians(degrees));
    // Now, draw the rotated/scaled image into the context
    CGContextScaleCTM(bitmap, 1.0, -1.0);
    CGContextDrawImage(bitmap, CGRectMake(-self.size.width / 2, -self.size.height / 2, self.size.width, self.size.height), [self CGImage]);
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;
}
@end

版权声明：本文博主原创文章，博客，未经同意不得转载。