HK_LongZhiMeng/Assets/Common/AnnotationTools/Scripts/AnnotationOpenImage.cs

using System.Text;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
using SFB;
using UnityEngine.Events;
using UniRx;
using System;
using UnityEngine.Networking;
[RequireComponent(typeof(Button))]
public class AnnotationOpenImage : MonoBehaviour, IPointerDownHandler
{
    public GameObject Output;
    public UnityAction<Texture2D> OnLoadTextureFinished;
#if UNITY_WEBGL && !UNITY_EDITOR
    //
    // WebGL
    //
    [DllImport("__Internal")]
    private static extern void UploadFile(string gameObjectName, string methodName, string filter, bool multiple);

    public void OnPointerDown(PointerEventData eventData) {
        UploadFile(gameObject.name, "OnFileUpload", ".png, .jpg,.bmp", false);
    }

    // Called from browser
    public void OnFileUpload(string url) {
        StartCoroutine(OutputRoutine(url));
    }
#else
    public void OnPointerDown(PointerEventData eventData) { }
    // Start is called before the first frame update
    void Start()
    {
        GetComponent<Button>().OnClickAsObservable()
            .Subscribe(_ => OnClick());
    }

    private void OnClick()
    {
        var extensions = new[] {
                new ExtensionFilter("Image Files", "png", "jpg", "jpeg" ),
            };
        var paths = StandaloneFileBrowser.OpenFilePanel("Title", "", extensions, false);
        if (paths.Length > 0)
        {
            StartCoroutine(OutputRoutine(new Uri(paths[0]).AbsoluteUri));
        }
    }
#endif
    private IEnumerator OutputRoutine(string url)
    {
        UnityWebRequest uwr = new UnityWebRequest(url);
        DownloadHandlerTexture downloadTexture = new DownloadHandlerTexture(true);
        uwr.downloadHandler = downloadTexture;
        yield return uwr.SendWebRequest();
        if (!(uwr.isNetworkError || uwr.isHttpError))
        {
            var loader = downloadTexture.texture;
            Output.GetComponent<Renderer>().material.SetTexture("_MainTex", loader);
            Output.transform.localScale = new Vector3(20, 1, (float)loader.height * ((float)20 / (float)loader.width));

            OnLoadTextureFinished?.Invoke(loader);

        }
    }
}