HoloLens-在Unity中捕获照片并将其保存到磁盘 [英] HoloLens -- Capturing Photo in Unity and Saving to Disk

问题描述

我正在尝试将捕获的照片保存到HoloLens的磁盘上.尝试基于在Unity中保存照片时遇到以下异常错误这个例子.有一阵子我无法找到正确的目录来保存文件，现在我想我终于可以使那部分工作了(请参阅下面的getFolderPath函数).但是，现在我在下面引用了此异常.有关如何解决此问题的任何想法?

I'm trying to save a captured photo to the disk on HoloLens. I'm getting the following exception error when trying to save a photo in Unity, based on this example. For a while I couldn't get the correct directory to save the file in, and now I think I've finally got that part working (see the getFolderPath function below). However, now I get this exception quoted below. Any ideas on how to fix this?

我正在使用Origami示例代码，并将此脚本PhotoCaptureTest.cs附加到Unity中的OrigamiCollection游戏对象.有人知道如何解决此问题，或者我如何可以更轻松地对其进行调试?

I'm using the Origami example code and I've simply attached this script PhotoCaptureTest.cs to the OrigamiCollection game object in Unity. Does anyone know how to fix this or how I can debug this more easily?

引发的异常:UnityEngine.dll中的'System.NullReferenceException' NullReferenceException:对象引用未设置为的实例 目的.在 UnityEngine.VR.WSA.WebCam.PhotoCapture.InvokeOnCapturedPhotoToDiskDelegate(OnCapturedToDiskCallback 回调，Int64 hResult)位于 UnityEngine.VR.WSA.WebCam.PhotoCapture.$ Invoke9(Int64实例，Int64 * args)在UnityEngine.Internal.$ MethodUtility.InvokeMethod(Int64 实例，Int64 *参数，IntPtr方法)(文件名:行:0)

Exception thrown: 'System.NullReferenceException' in UnityEngine.dll NullReferenceException: Object reference not set to an instance of an object. at UnityEngine.VR.WSA.WebCam.PhotoCapture.InvokeOnCapturedPhotoToDiskDelegate(OnCapturedToDiskCallback callback, Int64 hResult) at UnityEngine.VR.WSA.WebCam.PhotoCapture.$Invoke9(Int64 instance, Int64* args) at UnityEngine.Internal.$MethodUtility.InvokeMethod(Int64 instance, Int64* args, IntPtr method) (Filename: Line: 0)

using UnityEngine;
using System.Collections;
using UnityEngine.VR.WSA.WebCam;
using System.Linq;
using Windows.Storage;
using System;
using System.IO;

public class PhotoCaptureTest : MonoBehaviour {

    PhotoCapture photoCaptureObject = null;
    string folderPath = "";
    bool haveFolderPath = false;

    // Use this for initialization
    void Start ()
    {
        getFolderPath();
        while (!haveFolderPath)
        {
            Debug.Log("Waiting for folder path...");
        }
        Debug.Log("About to call CreateAsync");
        PhotoCapture.CreateAsync(false, OnPhotoCaptureCreated);
        Debug.Log("Called CreateAsync");
    }

    // Update is called once per frame
    void Update () {

    }

    async void getFolderPath()
    {
        StorageLibrary myPictures = await Windows.Storage.StorageLibrary.GetLibraryAsync(Windows.Storage.KnownLibraryId.Pictures);
        Windows.Storage.StorageFolder savePicturesFolder = myPictures.SaveFolder;
        Debug.Log("savePicturesFolder.Path is " + savePicturesFolder.Path);
        folderPath = savePicturesFolder.Path;
        haveFolderPath = true;
    }

    void OnPhotoCaptureCreated(PhotoCapture captureObject)
    {
        photoCaptureObject = captureObject;

        Resolution cameraResolution = PhotoCapture.SupportedResolutions.OrderByDescending((res) => res.width * res.height).First();

        CameraParameters c = new CameraParameters();
        c.hologramOpacity = 0.0f;
        c.cameraResolutionWidth = cameraResolution.width;
        c.cameraResolutionHeight = cameraResolution.height;
        c.pixelFormat = CapturePixelFormat.BGRA32;

        captureObject.StartPhotoModeAsync(c, false, OnPhotoModeStarted);
    }

    void OnStoppedPhotoMode(PhotoCapture.PhotoCaptureResult result)
    {
        photoCaptureObject.Dispose();
        photoCaptureObject = null;
    }

    private void OnPhotoModeStarted(PhotoCapture.PhotoCaptureResult result)
    {
        if (result.success)
        {
            string filename = string.Format(@"\CapturedImage{0}_n.jpg", Time.time);
            string filePath = folderPath + filename;
            string currentDir = Directory.GetCurrentDirectory();
            Debug.Log("Current working direcotry is " + currentDir);
            Debug.Log("Saving photo to " + filePath);

            try
            {
                photoCaptureObject.TakePhotoAsync(filePath, PhotoCaptureFileOutputFormat.JPG, OnCapturedPhotoToDisk);
            }
            catch (System.ArgumentException e)
            {
                Debug.LogError("System.ArgumentException:\n" + e.Message);
            }
        }
        else
        {
            Debug.LogError("Unable to start photo mode!");
        }
    }

    void OnCapturedPhotoToDisk(PhotoCapture.PhotoCaptureResult result)
    {
        if (result.success)
        {
            Debug.Log("Saved Photo to disk!");
            photoCaptureObject.StopPhotoModeAsync(OnStoppedPhotoMode);
        }
        else
        {
            Debug.Log("Failed to save Photo to disk");
        }
    }
}

推荐答案

我发现您捕获和保存照片的代码应该正确，并且遇到了与您相同的错误.

I find that your code to capture and save photos should be correct and I ran into the same error as you.

为避免该错误，我能够通过将目录更改为Application.persistentDataPath来保存照片，即将Start()修改为以下内容

To avoid the error, I was able to save photos by changing the directory to Application.persistentDataPath, i.e., modifying Start() to the following

// ...
void Start()
{
    folderPath = Application.persistentDataPath;
    PhotoCapture.CreateAsync(false, OnPhotoCaptureCreated);
}
// ...

然后可以在路径UserFiles\LocalAppData\<APPNAME>\LocalState\上找到照片，可以通过Hololens设备门户的文件资源管理器找到该文件.

The photo is then available at the path UserFiles\LocalAppData\<APPNAME>\LocalState\, which can be found through the Hololens Device Portal's File Explorer.

这篇关于HoloLens-在Unity中捕获照片并将其保存到磁盘的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！