我在尝试拍照(前置摄像头)时遇到崩溃，只有当用户使用画中画模式拍摄单独的应用视频时才会失败。如果用户没有画中画视频，一切正常。崩溃发生在这一行:

[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {

错误

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: '*** -[AVCaptureStillImageOutput captureStillImageAsynchronouslyFromConnection:completionHandler:] - inconsistent state.'

我尝试检查手机在使用画中画模式时是否一般无法拍照，但默认的 iOS 相机应用程序能够正常拍照(尽管可能使用不同的拍照方法). stillImageOutput 和 videoConnection 似乎设置良好并且不是零。

以下是导致此崩溃的代码，以防有帮助。

avCaptureSession = [[AVCaptureSession alloc] init];
AVCaptureDevice* cameraDevice = [GS60_FriendFeed_ScreenshotSelfie_Preview_View frontFacingCameraIfAvailable];
avCaptureSession.sessionPreset = avCaptureSessionPresetString;

NSError *error = nil;
AVCaptureDeviceInput *input = [AVCaptureDeviceInput deviceInputWithDevice:cameraDevice error:&error];
if (!input) {
    NSLog(@"ERROR: trying to open camera: %@", error);
}
[avCaptureSession addInput:input];
AVCaptureStillImageOutput* stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary *outputSettings = [[NSDictionary alloc] initWithObjectsAndKeys: AVVideoCodecJPEG, AVVideoCodecKey, nil];
[stillImageOutput setOutputSettings:outputSettings];
[avCaptureSession addOutput:stillImageOutput];
[avCaptureSession startRunning];

以后

AVCaptureConnection* videoConnection = nil;
AVCaptureStillImageOutput* stillImageOutput = [[avCaptureSession outputs] objectAtIndex:0];
for (AVCaptureConnection* connection in stillImageOutput.connections) {
    for (AVCaptureInputPort *port in [connection inputPorts]) {
        if ([[port mediaType] isEqual:AVMediaTypeVideo] ) {
            videoConnection = connection;
            break;
        }
    }
    if (videoConnection) { break; }
}

UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
AVCaptureVideoOrientation avcaptureOrientation = AVCaptureVideoOrientationPortrait;
if(orientation == UIInterfaceOrientationUnknown) {
    avcaptureOrientation = AVCaptureVideoOrientationPortrait;
} else if(orientation == UIInterfaceOrientationPortrait) {
    avcaptureOrientation = AVCaptureVideoOrientationPortrait;
} else if(orientation == UIInterfaceOrientationPortraitUpsideDown) {
    avcaptureOrientation = AVCaptureVideoOrientationPortraitUpsideDown;
} else if(orientation == UIInterfaceOrientationLandscapeLeft) {
    avcaptureOrientation = AVCaptureVideoOrientationLandscapeLeft;
} else if(orientation == UIInterfaceOrientationLandscapeRight) {
    avcaptureOrientation = AVCaptureVideoOrientationLandscapeRight;
}
[videoConnection setVideoOrientation:avcaptureOrientation];

//this line flips the image so it uses exactly what the preview shows
[videoConnection setVideoMirrored:YES];
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection completionHandler: ^(CMSampleBufferRef imageSampleBuffer, NSError *error) {
...

我希望能够拍照，但如果在画中画打开时无法拍照，了解如何检测我们将无法拍照仍然会有帮助。

感谢您的帮助。

最佳答案

确保连接存在并启用

if (!videoConnection || !videoConnection.enabled || !videoConnection.active) {
    // Raise error here / warn user... 
    return;
}
UIInterfaceOrientation orientation = [UIApplication sharedApplication].statusBarOrientation;
AVCaptureVideoOrientation avcaptureOrientation = AVCaptureVideoOrientationPortrait;

关于iOS NSInternalInconsistencyException 在应用程序使用 iOS9 画中画模式时拍照，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/39156883/