Question

我从这里复制了以下代码： https://code.msdn.microsoft.com/windowsapps/WindowsPhone-Store-81-vs-25c80c2a#content

MediaCapture captureManager;
    async private void InitCamera_Click(object sender, RoutedEventArgs e)
    {
        captureManager = new MediaCapture();
        await captureManager.InitializeAsync();
    }

    async private void StartCapturePreview_Click(object sender, RoutedEventArgs e)
    {
        capturePreview.Source = captureManager;
        await captureManager.StartPreviewAsync();
    }

    async private void StopCapturePreview_Click(object sender, RoutedEventArgs e)
    {
        await captureManager.StopPreviewAsync();
    }

    async private void CapturePhoto_Click(object sender, RoutedEventArgs e)
    {
        ImageEncodingProperties imgFormat = ImageEncodingProperties.CreateJpeg();

        // create storage file in local app storage 
        StorageFile file = await ApplicationData.Current.LocalFolder.CreateFileAsync(
            "TestPhoto.jpg",
            CreationCollisionOption.GenerateUniqueName);

        // take photo 
        await captureManager.CapturePhotoToStorageFileAsync(imgFormat, file);

        // Get photo as a BitmapImage 
        BitmapImage bmpImage = new BitmapImage(new Uri(file.Path));

        // imagePreivew is a <Image> object defined in XAML 
        imagePreview.Source = bmpImage;
    }

当我尝试运行时，未定义capturePreview。我删除了那一行，我得到两个例外：

抛出异常：mscorlib.ni.dll中的'System.ArgumentException'

抛出异常：mscorlib.ni.dll中的'System.ArgumentException'

你知道这个问题吗？ Windows phone 8.1 RT app

编辑：也可以在此处找到相同的代码：https://msdn.microsoft.com/en-us/library/windows.media.capture.mediacapture.aspx?f=255&MSPPError=-2147217396

Answer 1

“capturePreview”是捕获元素。您必须在页面中添加以下控件。

<CaptureElement x:Name="capturePreview" Width="320" Height="240" />

以下代码无效

1 个答案: