如何在 iOS xamarin 表單中獲取自定義渲染器相機的捕獲圖像

Question

我們在我們的應用程序中使用自定義相機。 我已經使用下面提到的鏈接實現了自定義相機。 單擊捕獲按鈕時，相機預覽停止並且工作正常，但是如何獲取捕獲的圖像數據，並且我想將圖像保存在圖庫中並返回路徑。 我已經通過使用 PictureCallback 在 android 中獲取了捕獲的圖像數據。 請幫我解決一下這個。

自定義相機鏈接： https : //docs.microsoft.com/en-us/xamarin/xamarin-forms/app-fundamentals/custom-renderer/view

Answer 1

看看這個博客。 為了在AVCapturePhotoCaptureDelegate獲取圖像數據，我添加了AVCapturePhotoOutput photoOutput 。 下面是一個例子：

public class UICameraPreview : UIView
{
    AVCaptureVideoPreviewLayer previewLayer;
    CameraOptions cameraOptions;

    AVCapturePhotoOutput photoOutput;

    public event EventHandler<EventArgs> Tapped;

    public AVCaptureSession CaptureSession { get; private set; }

    public bool IsPreviewing { get; set; }

    public UICameraPreview (CameraOptions options)
    {
        cameraOptions = options;
        IsPreviewing = false;
        Initialize ();
    }

    public override void LayoutSubviews()
    {
        base.LayoutSubviews();

        if (previewLayer != null)
            previewLayer.Frame = Bounds;
    }

    public override void TouchesBegan (NSSet touches, UIEvent evt)
    {
        base.TouchesBegan (touches, evt);
        OnTapped ();
    }

    protected virtual void OnTapped ()
    {
        var eventHandler = Tapped;
        if (eventHandler != null) {
            eventHandler (this, new EventArgs ());
        }
    }

    void Initialize ()
    {
        CaptureSession = new AVCaptureSession ();
        previewLayer = new AVCaptureVideoPreviewLayer (CaptureSession) {
            Frame = Bounds,
            VideoGravity = AVLayerVideoGravity.ResizeAspectFill
        };

        //self.photoOutput.capturePhoto(with: AVCapturePhotoSettings(), delegate: self)

        photoOutput = new AVCapturePhotoOutput();
        
        CaptureSession.AddOutput(photoOutput);

        photoOutput.CapturePhoto(AVCapturePhotoSettings.Create(),new myDelegate());

        var videoDevices = AVCaptureDevice.DevicesWithMediaType (AVMediaType.Video);
        var cameraPosition = (cameraOptions == CameraOptions.Front) ? AVCaptureDevicePosition.Front : AVCaptureDevicePosition.Back;
        var device = videoDevices.FirstOrDefault (d => d.Position == cameraPosition);

        if (device == null) {
            return;
        }

        NSError error;
        var input = new AVCaptureDeviceInput (device, out error);
        CaptureSession.AddInput (input);
        Layer.AddSublayer (previewLayer);
        CaptureSession.StartRunning ();
        IsPreviewing = true;
    }
}

public class myDelegate : AVCapturePhotoCaptureDelegate {

    public override void DidFinishCapture(AVCapturePhotoOutput captureOutput, AVCaptureResolvedPhotoSettings resolvedSettings, NSError error)
    {
        base.DidFinishCapture(captureOutput, resolvedSettings, error);
    }

    public override void DidFinishProcessingPhoto(AVCapturePhotoOutput output, AVCapturePhoto photo, NSError error)
    {
        base.DidFinishProcessingPhoto(output, photo, error);

        if (error == null)
        {
            var photodata = photo.FileDataRepresentation;
        }
    }
}

我還沒有將所有的 swift 代碼翻譯成 c#，如果您有任何問題，請隨時問我。