Question

我正在使用-writeImageToSavedPhotosAlbum将图片发送到照片库。我遇到的问题是，尽管指定了方向，但图像最终会出现错误的方向。

事实上，面向AVCaptureVideoOrientationPortrait的人似乎最终看起来像AVCaptureVideoOrientationPortraitUpsideDown，并且AVCaptureVideoOrientationLandscapeLeft最终看起来像AVCaptureVideoOrientationLandscapeRight，反之亦然。

为什么会出现这种情况？以下是一些更多细节：

我没有ViewController为我的视图进行自动方向更改所有图片都显示[image imageOrientation]等于AVCaptureVideoOrientationPortrait，但我会跟踪实际方向，并将其单独传递给-writeImageToSavedPhotosAlbum。

我正在使用：-writeImageToSavedPhotosAlbum:orientation:completionBlock:

如果有人可以对此有所了解，我会很感激。

更新：

尽管我在文档中读到了，

如果要保存UIImage对象，可以使用UIImage方法获取CGImageRef的CGImage，并将图像的imageOrientation转换为 ALAssetOrientation。

我继续改变了传递方向：

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，所有图像都以左边缘向下定向，就像它们是风景右侧一样。我仍然没有正确，但至少我让他们统一导向。

另一个更新：

这很有效。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

您遇到此问题，因为UIDeviceOrientation和ALAssetOrientation具有不同的枚举值。检查下面两个枚举的定义：

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
};

因此对于UIDeviceOrientationUnknown，同样是UIDeviceOrientationUnknown（int value 0）; 对于UIDeviceOrientationPortrait将等于ALAssetOrientationDown（int value 1）等等

Answer 2

您确定图像没有以正确的方向保存吗？您只是在显示时不尊重方向？

您可以在完成程序段中加载资产并检查其中的方向以确定。

为什么-writeImageToSavedPhotosAlbum错误地定位我的图片？

2 个答案: