如何在xamarin表单中使用设备摄像头自动捕获图像

Question

我想在没有用户交互的情况下自动捕获图像，我能够使用捕获按钮捕获图像，但我的要求是图像捕获应该自动请帮助我实现这一点。

Answer 1

做这件事有两个部分。您需要打开相机活动：

关于这一点，有多个教程：

Android

App.Instance.ShouldTakePicture += () => {
   var intent = new Intent(MediaStore.ActionImageCapture);
   intent.PutExtra(MediaStore.ExtraOutput, Uri.FromFile(file));
   StartActivityForResult(intent, 0);
};

国际标准化组织

imagePicker.FinishedPickingMedia += (sender, e) => {
            var filepath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "tmp.png");
var image = (UIImage)e.Info.ObjectForKey(new NSString("UIImagePickerControllerOriginalImage"));
            InvokeOnMainThread(() => {
                image.AsPNG().Save(filepath, false);
                App.Instance.ShowImage(filepath);
            });
            DismissViewController(true, null);
        };

下一步是使用面部识别，一旦你有了用户的脸，你就可以存储图像。

using (var stream = photo.GetStream())
{
    var faceServiceClient = new FaceServiceClient("{FACE_API_SUBSCRIPTION_KEY}");

    // Step 4a - Detect the faces in this photo.
    var faces = await faceServiceClient.DetectAsync(stream);
    var faceIds = faces.Select(face => face.FaceId).ToArray();

    // Step 4b - Identify the person in the photo, based on the face.
    var results = await faceServiceClient.IdentifyAsync(personGroupId, faceIds);
    var result = results[0].Candidates[0].PersonId;

    // Step 4c - Fetch the person from the PersonId and display their name.
    var person = await faceServiceClient.GetPersonAsync(personGroupId, result);
    UserDialogs.Instance.ShowSuccess($"Person identified is {person.Name}.");
}