WinRTError unknown error when using creationcollisionoption

Question

This works: Windows.Storage.ApplicationData.current.temporaryFolder.createFileAsync(photoFile)

But this: Windows.Storage.ApplicationData.current.temporaryFolder.createFileAsync(photoFile, Windows.Storage.CreationCollisionOption.replaceExisting)
throws an exception unknown error when passing the created file to mediaCaptureMgr.capturePhotoToStorageFileAsync

Why is that?

full code for reference:

Windows.Storage.ApplicationData.current.temporaryFolder.createFileAsync(photoFile, Windows.Storage.CreationCollisionOption.replaceExisting).then(
        function (newFile) {
            photoStorage = newFile;

            var photoProperties = photoPoster.createDefaultImageEncodingProperties();

            mediaCaptureMgr.capturePhotoToStorageFileAsync(photoProperties, photoStorage).then(
                function (result) {
                    // ...
                },
                function capturePhotoError(error) {
                    var exception = error; // threw unknown error!
                }
            );
        },
        function (error) {
            var exception = error;
        }
    );

R

Answer 1

Hi R,

I modified the "Media capture using webcam sample" and it works fine.  The code is ever so slightly different:

function capturePhoto() {
        sdkSample.displayStatus("Taking photo");
        return Windows.Storage.ApplicationData.current.temporaryFolder.createFileAsync(photoFile, Windows.Storage.CreationCollisionOption.replaceExisting).then(
        function (newFile) {
            photoStorage = newFile;
            var photoProperties = new Windows.Media.MediaProperties.ImageEncodingProperties();
            photoProperties.subtype = "JPEG";
            photoProperties.width = 320;
            photoProperties.height = 240;

            mediaCaptureMgr.capturePhotoToStorageFileAsync(photoProperties, photoStorage).then(
            function (result) {
                sdkSample.displayStatus("Photo Taken.  File " + photoStorage.path + "  ");
                var url = URL.createObjectURL(photoStorage, false);
                id("imageTag" + sdkSample.scenarioId).src = url;
            },
            function capturePhotoError(error) {
                sdkSample.displayStatus("An exception occurred trying to capturePhoto: " + error.message);
            });
        },
        function (error) {
            sdkSample.displayStatus("capturePhoto async exception " + error.message);
        });
    }

Give the sample a shot on your system with my modifications and let me know the result!

-Jeff

---

Jeff Sanders (MSFT)

Answer 2

strange.

I made the same change on the "Media capture using webcam sample" and get the same error as in my project:

"WinRTError: Unknown runtime error
   at completed (Function code:234:21)"

'WWAHost.exe' (Script): Loaded 'Script Code (MSAppHost/1.0)'. 
Exception was thrown at line 235, column 21 in Function code
0xc00d36b2 - JavaScript runtime error: Unknown runtime error

I'm running a Lenovo W510, Core i7, Windows 8 Consumer Preview booted from VHD

Answer 3

Did you use my code verbatim?

-Jeff

---

Jeff Sanders (MSFT)

Answer 4

I met the same problem.

Then I used Jeff's code verbatim, it works.

When using my own code , I got the same error.

My solution: 1. must define the width and height with the picture.

                    2. must invoke the method mediaCapture.initializeAsync(mediaCaputreSettings) before other methods.

Answer 5

Thanks Mini,

Those are great tips!

---

Jeff Sanders (MSFT)