一、准备工作

1、开发平台及SDK下载

微信开放平台

下载SDK

微信支付Demo下载

 

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【】。

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【】

步骤5：商户后台接收支付通知。api参见【】

步骤6：商户后台查询支付结果。，api参见【】

 

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\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:

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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\n" +req.sign+ "\n\n" );          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();      } }