Question

我尝试使用Windows RT / XAML开发模型创建可以使用Windows Phone 8.1相机的应用。

当我尝试从MediaCapture类调用任何一个捕获方法时，我得到一个带有消息＆＃34的ArgumentException;参数不正确。＆＃34;这是我的代码

    private async Task Initialize()
    {
        if (!DesignMode.DesignModeEnabled)
        {               
            await _mediaCaptureMgr.InitializeAsync();
            ViewFinder.Source = _mediaCaptureMgr;
            await _mediaCaptureMgr.StartPreviewAsync();
        }
    }

    private async void ViewFinder_OnTapped(object sender, TappedRoutedEventArgs e)
    {
        ImageEncodingProperties imageProperties = ImageEncodingProperties.CreateJpeg();

        var stream = new InMemoryRandomAccessStream();

        await _mediaCaptureMgr.CapturePhotoToStreamAsync(imageProperties, stream);

        _bitmap = new WriteableBitmap((int) ViewFinder.ActualWidth, (int) ViewFinder.ActualHeight);
        stream.Seek(0);
        await _bitmap.SetSourceAsync(stream);

        PreviewImage.Source = _bitmap;
        PreviewElements.Visibility = Visibility.Visible;
        ViewFinder.Visibility = Visibility.Collapsed;
        Buttons.Visibility = Visibility.Visible;
        Message.Visibility = Visibility.Collapsed;

        stream.Seek(0);
        var buffer = new global::Windows.Storage.Streams.Buffer((uint) stream.Size);
        stream.ReadAsync(buffer, (uint) stream.Size, InputStreamOptions.None);

        DataContext = buffer.ToArray();
        if (PhotoCaptured != null)
            PhotoCaptured(this, null);
    }

在页面加载时调用initialize方法，并在点击xaml中的CaptureElement时调用viewfinder_ontapped。

上引发了错误

await _mediaCaptureMgr.CapturePhotoToStreamAsync(imageProperties, stream);

我真的很奇怪的是，我下载了winrt xaml工具包http://winrtxamltoolkit.codeplex.com/的最新资源，并尝试使用类似代码的示例相机应用程序。它在MediaCapture.CapturePhotoToStorageFileAsync（）上抛出相同的错误。任何人都可以帮我确定原因吗？

MediaCapture.CapturePhotoToStreamAsync（）和MediaCapture.CapturePhotoToStorageFileAsync（）抛出参数异常

0 个答案: