支付成功页添加返回按钮监听；

app.json

 {
   "pages": [
-    "pages/paysuccess/paysuccess",
     "pages/login/login",
+    "pages/paysuccess/paysuccess",
     "pages/home/home",
     "pages/balance/balance",
     "pages/scan/scan"

const/actioncmd.js

@@ -82,3 +82,6 @@ export const ACTION_VERIFY_FAILED = "ACTION_VERIFY_FAILED";
 
 //退出事件
 export const ACTION_QUIT = "ACTION_QUIT";
+
+//支付成功页点击返回按钮
+export const ACTION_PAYSUCCESS_PAGE_BACK = "ACTION_PAYSUCCESS_PAGE_BACK";
\ No newline at end of file

pages/paysuccess/paysuccess.js

 import { ACTION_PRINT_RESULT } from '../../const/actioncmd'
 import { ACTION_REPRINT } from '../../const/actioncmd'
 import { ACTION_GO_HOME } from '../../const/actioncmd'
+import { ACTION_PAYSUCCESS_PAGE_BACK } from '../../const/actioncmd'
 
 Page({
+  //回退到上一个页面
+  events: {
+    onBack(e) {
+      console.log('onBack触发');
+      my.ix.sendBuddyMessage({
+        // 填入目标小程序的 AppID
+        target: getApp().globalData.backScreenAppId,
+        data: {
+          action: ACTION_PAYSUCCESS_PAGE_BACK,
+          data: null
+        },
+        success: (res) => {
+          e.preventDefault();
+        },
+        fail: (res) => {
+          console.info(`sendBuddyMessage failed: ${JSON.stringify(res)}`);
+        }
+      });
+    }
+  },
+
   data: {
     orderPriceYuan: "--.--",
     orderPriceFen: 0,