微信支付调用getWxpayfaceRawdata 时候总是返回空这是为什么？

WxPayFace.getInstance().getWxpayfaceRawdata(object : IWxPayfaceCallback() {
    @Throws(RemoteException::class)
    override fun response(info: Map<*, *>?) {
        if (info == null) {
            return
        } else {
            val code = info["return_code"] as String
            val msg = info["return_msg"] as String
            val rawdata = info["rawdata"].toString()
            Logger.d("微信支付raw数据是:" + JSON.toJSON(info))
            if (code == null || rawdata == null || !code.equals("SUCCESS")) {
                callBack?.let { it("设备未获取到rawdata") }
                return
            } else { 
                getPayAuoth(rawdata, callBack)
            }
        }
    }
})

raw数据是:{"return_code":"FAIL","return_msg":"Service Unconnected"}