iOS开发—— UIImage数据的保存

　　1、保存图片和方向

　　[userDefault setObject:UIImagePNGRepresentation(image) forKey:udUserImage];

　　[userDefault setObject:[NSNumber numberWithInteger:image.imageOrientation] forKey:udUserImageOrientation];

　　2、获取图片和方向

　　NSData* imageData = [userDefault objectForKey:udUserImage];

　　UIImage *userImage = [UIImage imageWithData:imageData];

　　NSInteger imageOrientation = [[userDefault objectForKey:udUserImageOrientation] integerValue];

　　3、显示图片

　　imageView.image = [self fixOrientationWithImage:userImage AndImageOrientation:imageOrientation];

- (UIImage *)fixOrientationWithImage:(UIImage *)aImage AndImageOrientation:(NSInteger)imageOrientation {

if (imageOrientation == UIImageOrientationUp)

return aImage;

CGAffineTransform transform = CGAffineTransformIdentity;

switch (imageOrientation) {

case UIImageOrientationDown:

case UIImageOrientationDownMirrored:

transform = CGAffineTransformTranslate(transform, aImage.size.width, aImage.size.height);

transform = CGAffineTransformRotate(transform, M_PI);

break;

case UIImageOrientationLeft:

case UIImageOrientationLeftMirrored:

transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);

transform = CGAffineTransformRotate(transform, M_PI_2);

break;

case UIImageOrientationRight:

case UIImageOrientationRightMirrored:

transform = CGAffineTransformTranslate(transform, 0, aImage.size.height);

transform = CGAffineTransformRotate(transform, -M_PI_2);

break;

default:

break;

}

switch (imageOrientation) {

case UIImageOrientationUpMirrored:

case UIImageOrientationDownMirrored:

transform = CGAffineTransformTranslate(transform, aImage.size.width, 0);

transform = CGAffineTransformScale(transform, -1, 1);

break;

case UIImageOrientationLeftMirrored:

case UIImageOrientationRightMirrored:

transform = CGAffineTransformTranslate(transform, aImage.size.height, 0);

transform = CGAffineTransformScale(transform, -1, 1);

break;

default:

break;

}

CGContextRef ctx = CGBitmapContextCreate(NULL, aImage.size.width, aImage.size.height,

CGImageGetBitsPerComponent(aImage.CGImage), 0,

CGImageGetColorSpace(aImage.CGImage),

CGImageGetBitmapInfo(aImage.CGImage));

CGContextConcatCTM(ctx, transform);

switch (imageOrientation) {

case UIImageOrientationLeft:

case UIImageOrientationLeftMirrored:

case UIImageOrientationRight:

case UIImageOrientationRightMirrored:

// Grr...

CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.height,aImage.size.width), aImage.CGImage);

break;

default:

CGContextDrawImage(ctx, CGRectMake(0,0,aImage.size.width,aImage.size.height), aImage.CGImage);

break;

}

CGImageRef cgimg = CGBitmapContextCreateImage(ctx);

UIImage *img = [UIImage imageWithCGImage:cgimg];

CGContextRelease(ctx);

CGImageRelease(cgimg);

return img;

}