unity5.4以上www可以设置请求超时时间了

IEnumerator Test()

    {

        UnityWebRequest wr = new UnityWebRequest();

        wr.url = "www.baidu.com";

        wr.timeout = 2;//超时时间

        yield return wr.SendWebRequest();

        //获得文本

        string text = wr.downloadHandler.text;

        //获得字节数组

        byte[] datas = wr.downloadHandler.data;

        //图片获取方式

       UnityWebRequest texture =  UnityWebRequestTexture.GetTexture("img url");

        texture.timeout = 3;//超时时间

       yield return texture.SendWebRequest();

       Texture2D tex2D = DownloadHandlerTexture.GetContent(texture);

        //音频获取方式

       UnityWebRequest audio = UnityWebRequestMultimedia.GetAudioClip("url",AudioType.ACC);

        yield return audio.SendWebRequest();

       AudioClip ac =  DownloadHandlerAudioClip.GetContent(audio);

        //视频

       UnityWebRequest movie = UnityWebRequestMultimedia.GetMovieTexture("url");

         yield return movie.SendWebRequest();

       MovieTexture mt =  DownloadHandlerMovieTexture.GetContent(movie);

        //assstbundle

        AssetBundle ab = DownloadHandlerAssetBundle.GetContent(wr);

    }