untiy使用http下载资源

提醒

部分API需要将Unity的 Edit/PrejectSetting/Player/OtherSetttings/AConfiguration/ApiCompatibilityLevel 设为.NetFramework 才可以使用

下载一个资源并保存到本地

    private IEnumerator DownloadFormServer_IE(string url, string path)//从服务器下载资源  path保存路径
    {
        Debug.Log("正在下载" + url);	
        string assetName = Path.GetFileName(url);
        UnityWebRequest request = UnityWebRequest.Get(url);       
        request.SendWebRequest();
        if (request.result == UnityWebRequest.Result.ProtocolError || request.result == UnityWebRequest.Result.ConnectionError)
        {
            Debug.Log(request.responseCode);
            Debug.Log(request.error);
            yield break;
        }
        while (!request.isDone)
        {
            string totalDownloadDataStr = "0kb";//总下载量 不是下载速度，可以根据总下载量计算下载速度
            if (request.downloadHandler != null && request.downloadHandler.data != null)
            {
                float speed = request.downloadHandler.data.Length / 1024;
                if (speed > 1024)
                {
                    speed = (speed / 1024);
                    totalDownloadDataStr = speed.ToString("f") + "mb";                
                }
                else
                { 
                    totalDownloadDataStr = speed + "kb";                
                }
            }
            //打开一个面板显示下载进度条 UIKit是QF框架提供的API
            UIKit.OpenPanel<AlertPanel>(new AlertPanelData(
                "正在下载" + assetName + "\n"
                + "进度" + (request.downloadProgress*100).ToString("f") + "%  "+ totalDownloadDataStr + "\n"
                + "第" + (assetsManagerModel.currentDownlaodFinishIndex + 1) + "\\总共" + assetsManagerModel.waitDownloadAssetsList.Count
                ));
            yield return null;
        }

        DownloadHandler downloadHandler = request.downloadHandler;
        Debug.Log("下载完成");
        byte[] data = request.downloadHandler.data;
        using (FileStream fs = new FileStream(path, FileMode.Create))//将下载好的数据写入本地
        {
            fs.Write(data, 0, data.Length);
        }
    }

下载一张图片

    private IEnumerator DownloadOnePicture_IE(string url, Action<Texture2D> callBack)//在callBack里可以直接对下载的图片进行例如给精灵赋值这类操作
    {
        if (string.IsNullOrEmpty(url)) yield break;
        UnityWebRequest request = UnityWebRequestTexture.GetTexture(url);
        yield return request.SendWebRequest();
        Texture2D texture2D = DownloadHandlerTexture.GetContent(request);
        callBack?.Invoke(texture2D);
    }