Android微信支付SDK开发

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

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

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<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

1 2	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

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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 "+result.get("prepay_id")+" ");             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:

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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

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//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 = "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 "+req.sign+" ");         show.setText(sb.toString());         Log.e("orion", signParams.toString());      }

1 2	//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

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@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();     } }