android app微信支付成功，就是不调用回调页

有谁Android做成功的，请指导指导 ，，，

我按到文档来的，，但是sign是我直接通过appId，预支付订单，Md5生成的，没有用后台返回的，，支付已经成功。。



package com.jialimei.jialimei.wxapi;



import com.jialimei.jialimei.Constants;


import com.jialimei.jialimei.activity.PayOKActivity;
import com.tencent.mm.sdk.constants.ConstantsAPI;
import com.tencent.mm.sdk.modelbase.BaseReq;
import com.tencent.mm.sdk.modelbase.BaseResp;
import com.tencent.mm.sdk.openapi.IWXAPI;
import com.tencent.mm.sdk.openapi.IWXAPIEventHandler;
import com.tencent.mm.sdk.openapi.WXAPIFactory;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

public class WXPayEntryActivity extends Activity implements IWXAPIEventHandler{

private static final String TAG = "MicroMsg.SDKSample.WXPayEntryActivity";

private IWXAPI api;
private Intent intent;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.pay_ok_layout);


api = WXAPIFactory.createWXAPI(this,Constants.APP_ID);

api.handleIntent(getIntent(),this);
}

@Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
setIntent(intent);
api.handleIntent(intent, this);
}

@Override
public void onReq(BaseReq req) {
}

@Override
public void onResp(BaseResp resp) {


if (resp.errCode==0){
Toast.makeText(WXPayEntryActivity.this,resp.errCode+"",Toast.LENGTH_SHORT).show();
intent=new Intent(WXPayEntryActivity.this, PayOKActivity.class);
startActivity(intent);
// Intent intent = new Intent();
// intent.setAction("com.jialimei.weixinpay");
// //要发送的内容
// intent.putExtra("errCode", resp.errCode);
// //发送 一个无序广播
// sendBroadcast(intent);
finish();

}else {
intent=new Intent(WXPayEntryActivity.this, PayOKActivity.class);
startActivity(intent);
Toast.makeText(WXPayEntryActivity.this,"支付失败。。。",Toast.LENGTH_SHORT).show();

}


Log.i("errCode==========",resp.errCode+"");
}

}


回调页的代码