安卓app调试微信拉起支付时总是报错

IWXAPI api = WXAPIFactory.createWXAPI(this, appId);
PayReq req = new PayReq();
req.appId            = appId;
req.partnerId        = MCH_ID;
req.prepayId         = d.getPrepayId();
req.packageValue     = "Sign=WXPay";
req.nonceStr         = d.getNoncestr();
req.timeStamp        = d.getTimestamp();
req.sign             = d.getSign();
boolean b = api.sendReq(req);
if (b) {
    XToastUtils.toast("已发送请求");
} else {
    XToastUtils.toast("发送失败");
}

报错：
W/MicroMsg.SDK.WXMsgImplComm: validateAppSignatureForPackage ex com.tencent.mm
E/MicroMsg.SDK.WXApiImplV10: sendReq failed for wechat app signature check failed

是什么原因
appId是公众号的appid还是移动应用的appid