图像正在旋转,因为您将图像保存为JPEG,如果您将图像保存在PNG中,则方向不会改变.这里是解决方向问题的代码.
原文链接：https://www.f2er.com/php/131220.html- (UIImage *)fixrotation:(UIImage *)image{
if (image.imageOrientation == UIImageOrientationUp) return image;
CGAffineTransform transform = CGAffineTransformIdentity;
switch (image.imageOrientation) {
case UIImageOrientationDown:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform,image.size.width,image.size.height);
transform = CGAffineTransformRotate(transform,M_PI);
break;
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
transform = CGAffineTransformTranslate(transform,0);
transform = CGAffineTransformRotate(transform,M_PI_2);
break;
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform,-M_PI_2);
break;
case UIImageOrientationUp:
case UIImageOrientationUpMirrored:
break;
}
switch (image.imageOrientation) {
case UIImageOrientationUpMirrored:
case UIImageOrientationDownMirrored:
transform = CGAffineTransformTranslate(transform,0);
transform = CGAffineTransformScale(transform,-1,1);
break;
case UIImageOrientationLeftMirrored:
case UIImageOrientationRightMirrored:
transform = CGAffineTransformTranslate(transform,image.size.height,1);
break;
case UIImageOrientationUp:
case UIImageOrientationDown:
case UIImageOrientationLeft:
case UIImageOrientationRight:
break;
}
// Now we draw the underlying CGImage into a new context,applying the transform
// calculated above.
CGContextRef ctx = CGBitmapContextCreate(NULL,CGImageGetBitsPerComponent(image.CGImage),CGImageGetColorSpace(image.CGImage),CGImageGetBitmapInfo(image.CGImage));
CGContextConcatCTM(ctx,transform);
switch (image.imageOrientation) {
case UIImageOrientationLeft:
case UIImageOrientationLeftMirrored:
case UIImageOrientationRight:
case UIImageOrientationRightMirrored:
// Grr...
CGContextDrawImage(ctx,CGRectMake(0,image.size.width),image.CGImage);
break;
default:
CGContextDrawImage(ctx,image.size.height),image.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;
}
