点快了就报着个错，我该怎么 修改？
Cannot set property 'classname' of undefined; [Component] Event Handler Error @ pages/games/game#bound gameda
TypeError: Cannot set property 'classname' of undefined
at ye.gameda (http://127.0.0.1:63953/appservice/pages/games/game.js:270:36)
at Object.r.safeCallback (WAService.js:1:857898)
at WAService.js:1:1048426
at r (WAService.js:1:982076)
at WAService.js:1:982184
at WAService.js:1:253666
at n (http://127.0.0.1:63953/appservice/appservice?t=1562135087132:1159:27752)
at e.exports.<anonymous> (http://127.0.0.1:63953/appservice/appservice?t=1562135087132:1159:28094)
at http://127.0.0.1:63953/appservice/appservice?t=1562135087132:1159:13287
at Array.forEach (<anonymous>)
console.error @ VM692:1
errorReport @ WAService.js:1
thirdErrorReport @ WAService.js:1
(anonymous) @ WAService.js:1
(anonymous) @ WAService.js:1
r.safeCallback @ WAService.js:1
r.call @ WAService.js:1
message @ WAService.js:1
r.safeCallback @ WAService.js:1
(anonymous) @ WAService.js:1
r @ WAService.js:1
(anonymous) @ WAService.js:1
(anonymous) @ WAService.js:1
n @ appservice?t=1562135087132:1159
(anonymous) @ appservice?t=1562135087132:1159
(anonymous) @ appservice?t=1562135087132:1159
_ws.onmessage @ appservice?t=1562135087132:1159
<view class='{{item.classname}}' > 这个是data中的原始值
{
word1: "Pedestrian\r\n Street",
classname: 'text-bg',
pipei: "8",
textfonname: 'text-fon',
flag: true
}, 这个是点击事件里面不同条件下的改值
wordMsg[g1].classname = 'text-bg1';
wordMsg[value_1].classname = 'text-bg2';
wordMsg[value_1].classname = 'text-bg';
wordMsg[value_1].classname = 'text-bg3';
wordMsg[value_1].classname = 'text-bg';
这样写有什么问题吗？