为什么-writeImageToSavedPhotosAlbum不正确地定位我的照片？

Question

我使用-writeImageToSavedPhotosAlbum将图像发送到照片库。我遇到的问题是，尽管指定了方向，图像最终的方向却是错误的。

事实上，似乎是定向AVCaptureVideoOrientationPortrait末看起来像AVCaptureVideoOrientationPortraitUpsideDown， 和AVCaptureVideoOrientationLandscapeLeft结束看起来像AVCaptureVideoOrientationLandscapeRight，反之亦然的。

为什么会有这种情况发生？这里有一些更多的细节：

我没有ViewController做我的看法的自动方向更改。
所有图片显示[image imageOrientation]等于AVCaptureVideoOrientationPortrait，但我跟踪实际方向并将其单独传递给-writeImageToSavedPhotosAlbum。

我使用：-writeImageToSavedPhotosAlbum:orientation:completionBlock:

我会很感激，如果有人可以提供一些线索到此。

UPDATE：

尽管我的文档中读取，

如果你想保存一个UIImage对象，你可以使用UIImage的方法 CGImage获得CGImageRef，投图像的imageOrientation为 ALAssetOrientation。

我继续改变了我在传递方向：

switch (lastOrientation) { 
    case UIDeviceOrientationPortrait: 
    default: 
     alOrientation = ALAssetOrientationUp; 
     break; 
    case UIDeviceOrientationPortraitUpsideDown: 
     alOrientation = ALAssetOrientationDown; 
     break; 
    case UIDeviceOrientationLandscapeLeft: 
     alOrientation = ALAssetOrientationLeft; 
     break; 
    case UIDeviceOrientationLandscapeRight: 
     alOrientation = ALAssetOrientationRight; 
     break; 

} 
[library writeImageToSavedPhotosAlbum:[image CGImage] 
          orientation:(ALAssetOrientation) alOrientation// [image imageOrientation] 
         completionBlock:^(NSURL *assetURL, NSError *error) { 
          NSLog(@"completion block"); 
         }]; 

现在，所有的图像得到取向为它们的左边缘下来，仿佛他们是景观权。我仍然没有对，但至少我有统一导向。

另一个更新：

这个工程。为什么，我不知道：

switch (lockedOrientation) { 
     case UIDeviceOrientationPortrait: 
     default: 
      alOrientation = ALAssetOrientationRight; //3 instead ofALAssetOrientationUp; 
      break; 
     case UIDeviceOrientationPortraitUpsideDown: 
      alOrientation = ALAssetOrientationLeft; //2 insted of ALAssetOrientationDown; 
      break; 
     case UIDeviceOrientationLandscapeLeft: 
      alOrientation = ALAssetOrientationUp; //0 instead of ALAssetOrientationLeft; 
      break; 
     case UIDeviceOrientationLandscapeRight: 
      alOrientation = ALAssetOrientationDown; //1 instead of ALAssetOrientationRight; 
      break; 

    } 
    [library writeImageToSavedPhotosAlbum:[image CGImage] 
           orientation:(ALAssetOrientation) alOrientation// [image imageOrientation] 
          completionBlock:^(NSURL *assetURL, NSError *error) { 
           NSLog(@"completion block"); 
          }]; 

Answer 1

您有此问题，因为UIDeviceOrientation和ALAssetOrientation具有不同的枚举值。检查定义以下两个枚举：

typedef NS_ENUM(NSInteger, UIDeviceOrientation) { 
    UIDeviceOrientationUnknown, 
    UIDeviceOrientationPortrait,   // Device oriented vertically, home button on the bottom 
    UIDeviceOrientationPortraitUpsideDown, // Device oriented vertically, home button on the top 
    UIDeviceOrientationLandscapeLeft,  // Device oriented horizontally, home button on the right 
    UIDeviceOrientationLandscapeRight,  // Device oriented horizontally, home button on the left 
    UIDeviceOrientationFaceUp,    // Device oriented flat, face up 
    UIDeviceOrientationFaceDown    // Device oriented flat, face down 
}; 

typedef NS_ENUM(NSInteger, ALAssetOrientation) { 
    ALAssetOrientationUp,   // default orientation 
    ALAssetOrientationDown,   // 180 deg rotation 
    ALAssetOrientationLeft,   // 90 deg CCW 
    ALAssetOrientationRight,   // 90 deg CW 
    ALAssetOrientationUpMirrored, // as above but image mirrored along other axis. horizontal flip 
    ALAssetOrientationDownMirrored, // horizontal flip 
    ALAssetOrientationLeftMirrored, // vertical flip 
    ALAssetOrientationRightMirrored, // vertical flip 
}; 

所以对于UIDeviceOrientationUnknown同样会UIDeviceOrientationUnknown（int值0）;对于UIDeviceOrientationPortrait， 将等于ALAssetOrientationDown（int值1）等等

Answer 2

您确定图像没有以正确的方向保存，并且您在显示时只是不尊重方向？

您可以在完成块中加载资产并检查确定的方向。