（iOS）急！环信视频过程中怎么切换前后摄像头

另外，请官方添加一下前后摄像头切换功能吧！ 这个是最基本的功能。所有的视频都需要做。

环信封装之后，我们开发再来做这个事情，就非常困难了！

demo2.0的实时视频，本地的视频显示是在demo上做的。具体代码在CallViewController->- (void)_initializeCamera方法中。你可以添加以下代码，在点击切换时，调用-swapFrontAndBackCameras， 亲测有效

- (AVCaptureDevice *)cameraWithPosition:(AVCaptureDevicePosition)position

{

    _position = position;

    NSArray *devices = [AVCaptureDevice devicesWithMediaType:AVMediaTypeVideo];

    for ( AVCaptureDevice *device in devices )

        if ( device.position == position )

            return device;

    return nil;

}



- (void)swapFrontAndBackCameras {

    // Assume the session is already running

    

    NSArray *inputs = _session.inputs;

    for ( AVCaptureDeviceInput *input in inputs ) {

        AVCaptureDevice *device = input.device;

        if ( [device hasMediaType:AVMediaTypeVideo] ) {

            AVCaptureDevicePosition position = device.position;

            AVCaptureDevice *newCamera = nil;

            AVCaptureDeviceInput *newInput = nil;

            

            if (_position == AVCaptureDevicePositionFront)

                newCamera = [self cameraWithPosition:AVCaptureDevicePositionBack];

            else

                newCamera = [self cameraWithPosition:AVCaptureDevicePositionFront];

            newInput = [AVCaptureDeviceInput deviceInputWithDevice:newCamera error:nil];

            

            // beginConfiguration ensures that pending changes are not applied immediately

            [_session beginConfiguration];

            

            [_session removeInput:input];

            [_session addInput:newInput];

            

            // Changes take effect once the outermost commitConfiguration is invoked.

            [_session commitConfiguration];

            break;

        }

    }

}

请问一下 你这个问题解决了么