Android微信支付SDK开发

采得百花成蜜后，为谁辛苦为谁甜。这篇文章主要讲述Android微信支付SDK开发相关的知识，希望能为你提供帮助。
一、准备工作
1、开发平台及SDK下载
微信开放平台
https://open.weixin.qq.com
下载SDK
【Android微信支付SDK开发】微信支付Demo下载
http://pay.weixin.qq.com/wiki/doc/api/app.php?chapter=11_1

2、创建应用
创建移动应用获取 AppID AppSecret
要获取支付功能还需要开发者资质认证，300RMB/年的费用，貌似是开放平台中唯一要收费的…

3、androidMainfest文件修改
权限

< uses-permission android:name="android.permission.INTERNET"/> < uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> < uses-permission android:name="android.permission.ACCESS_WIFI_STATE"/> < uses-permission android:name="android.permission.READ_PHONE_STATE"/> < uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

二、业务流程
商户系统和微信支付系统主要交互说明：
步骤1：用户在商户APP中选择商品，提交订单，选择微信支付。
步骤2：商户后台收到用户支付单，调用微信支付统一下单接口。参见【统一下单API】。
步骤3：统一下单接口返回正常的prepay_id，再按签名规范重新生成签名后，将数据传输给APP。参与签名的字段名为appId，partnerId，prepayId，nonceStr，timeStamp，package。注意：package的值格式为Sign=WXPay
步骤4：商户APP调起微信支付。api参见本章节【app端开发步骤说明】
步骤5：商户后台接收支付通知。api参见【支付结果通知API】
步骤6：商户后台查询支付结果。，api参见【查询订单API】

三、开发
1、注册应用

final IWXAPI msgApi = WXAPIFactory.createWXAPI(this, null); msgApi.registerApp(Constants.APP_ID);

2、调用支付统一下单接口，并返回PrepayID

private class GetPrepayIdTask extends AsyncTask< Void, Void, Map< String,String> > { private ProgressDialog dialog; @Override protected void onPreExecute() { dialog = ProgressDialog.show(PayActivity.this, getString(R.string.app_tip), getString(R.string.getting_prepayid)); } @Override protected void onPostExecute(Map< String,String> result) { if (dialog != null) { dialog.dismiss(); } sb.append("prepay_id\n"+result.get("prepay_id")+"\n\n"); show.setText(sb.toString()); resultunifiedorder=result; } @Override protected void onCancelled() { super.onCancelled(); } @Override protected Map< String,String> doInBackground(Void... params) { String url = String.format("https://api.mch.weixin.qq.com/pay/unifiedorder"); String entity = genProductArgs(); Log.e("orion",entity); byte[] buf = Util.httpPost(url, entity); String content = new String(buf); Log.e("orion", content); Map< String,String> xml=decodeXml(content); return xml; } }

设置统一下单参数:

private String genProductArgs() { StringBuffer xml = new StringBuffer(); try { String nonceStr = genNonceStr(); xml.append("< /xml> "); List< NameValuePair> packageParams = new LinkedList< NameValuePair> (); packageParams.add(new BasicNameValuePair("appid", Constants.APP_ID)); packageParams.add(new BasicNameValuePair("body", "APP pay test")); packageParams.add(new BasicNameValuePair("mch_id", Constants.MCH_ID)); packageParams.add(new BasicNameValuePair("nonce_str", nonceStr)); packageParams.add(new BasicNameValuePair("notify_url", "http://121.40.35.3/test")); packageParams.add(new BasicNameValuePair("out_trade_no",genOutTradNo())); packageParams.add(new BasicNameValuePair("spbill_create_ip","127.0.0.1")); packageParams.add(new BasicNameValuePair("total_fee", "1")); packageParams.add(new BasicNameValuePair("trade_type", "APP")); String sign = genPackageSign(packageParams); packageParams.add(new BasicNameValuePair("sign", sign)); String xmlstring =toXml(packageParams); return xmlstring; } catch (Exception e) { Log.e(TAG, "genProductArgs fail, ex = " + e.getMessage()); return null; } }

3、设置PayReq请求的参数，并发送支付请求

//设置PayReq请求的参数 private void genPayReq() { req.appId = Constants.APP_ID; req.partnerId = Constants.MCH_ID; req.prepayId = resultunifiedorder.get("prepay_id"); req.packageValue = "https://www.songbingjia.com/android/prepay_id="+resultunifiedorder.get("prepay_id"); req.nonceStr = genNonceStr(); req.timeStamp = String.valueOf(genTimeStamp()); List< NameValuePair> signParams = new LinkedList< NameValuePair> (); signParams.add(new BasicNameValuePair("appid", req.appId)); signParams.add(new BasicNameValuePair("noncestr", req.nonceStr)); signParams.add(new BasicNameValuePair("package", req.packageValue)); signParams.add(new BasicNameValuePair("partnerid", req.partnerId)); signParams.add(new BasicNameValuePair("prepayid", req.prepayId)); signParams.add(new BasicNameValuePair("timestamp", req.timeStamp)); req.sign = genAppSign(signParams); sb.append("sign\n"+req.sign+"\n\n"); show.setText(sb.toString()); Log.e("orion", signParams.toString()); }

//发送请求 msgApi.sendReq(req);

4、处理结果回调
实现微信API的IWXAPIEventHandler接口
api.handleIntent(getIntent(), new IWXAPIEventHandler);
在IWXAPIEventHandler的onResp(BaseResp resp)中处理请求回调

@Override public void onResp(BaseResp resp) { Log.d(TAG, "onPayFinish, errCode = " + resp.errCode); if (resp.getType() == ConstantsAPI.COMMAND_PAY_BY_WX) { //处理PayReq的回调 AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setTitle(R.string.app_tip); builder.setMessage(getString(R.string.pay_result_callback_msg, resp.errStr +"; code=" + String.valueOf(resp.errCode))); builder.show(); } }