そのため、画像の取得時にデバイスの向きを保存し、パラメータとして以下のメソッドに渡します。ここでは、メソッドに任意の名前を付けて、パラメータを渡します。orientation
switch (orientation) {
case UIDeviceOrientationPortrait:
[featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(0.))];
break;
case UIDeviceOrientationPortraitUpsideDown:
[featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(180.))];
break;
case UIDeviceOrientationLandscapeLeft:
[featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(90.))];
break;
case UIDeviceOrientationLandscapeRight:
[featureLayer setAffineTransform:CGAffineTransformMakeRotation(DegreesToRadians(-90.))];
break;
case UIDeviceOrientationFaceUp:
case UIDeviceOrientationFaceDown:
default:
break; // leave the layer in its last known orientation
}
ここで使用したマクロDegreesToRadians()
は次のとおりです
static CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;};
これは間違いなく機能します。
ハッピーコーディング:)
編集
上記のコードがうまく機能しない場合は、これを使用してください
@interface UIImage (RotationMethods)
- (UIImage *)imageRotatedByDegrees:(CGFloat)degrees;
@end
@implementation UIImage (RotationMethods)
- (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
次に、上記の関数を以下のように呼び出します
switch (orientation) {
case UIDeviceOrientationPortrait:
image = [image imageRotatedByDegrees:0];
break;
case UIDeviceOrientationPortraitUpsideDown:
image = [image imageRotatedByDegrees:180];
break;
case UIDeviceOrientationLandscapeLeft:
image = [image imageRotatedByDegrees:-90];
break;
case UIDeviceOrientationLandscapeRight:
image = [image imageRotatedByDegrees:90];
break;
case UIDeviceOrientationFaceUp:
case UIDeviceOrientationFaceDown:
default:
break; // leave the layer in its last known orientation
}
画像が必要な向きになっていない場合は、上記imageRotatedByDegrees
のすべての引数に90を追加します(つまり、0の場合は0 + 90になります)。または必要に応じて追加します。
編集1
UIDeviceOrientation curDeviceOrientation = [[UIDevice currentDevice] orientation];