WWW www = new WWW("http://u3dchina.com/template/singcere_dw/common/images/logo.png");
yield return www;
txt2d = new Texture2D(4, 4, TextureFormat.ARGB32, false);
www.LoadImageIntoTexture(txt2d);//Resources.LoadAssetAtPath("http://u3dchina.com/template/singcere_dw/common/images/logo.png", typeof(Texture)) as Texture;