不允許重複，指數已經指定

Question

我在與AngularJS中繼的問題：

<table class="data_table" style="margin: 0 5px; width: calc(100% - 10px);"> 
    <tr> 
    <th>Activity</th> 
    <th ng-repeat="date in activitiesRangeInfo.labels">{{date | date: 'd/MM'}}</th> 
    </tr> 
    <tr ng-repeat="activity in activitiesRangeInfo.generated_datasets track by $index"> 
    <th>{{activitiesRangeInfo.all_activities[$index]}}</th> 
    <td align="center" ng-repeat="inner in activitiesRangeInfo.generated_datasets[$index] track by $index"> 
     {{inner | number: 1}} 
    </td> 
    </tr> 
</table> 

和這組數據：

$scope.activitiesRangeInfo = { 
    all_activities: ["Tennis"], 
    generated_datasets: [[0, 0, 420, 0]], 
    labels: JSON.parse('["2016-10-22T13:00:00.000Z","2016-10-23T13:00:00.000Z","2016-10-24T13:00:00.000Z","2016-10-25T13:00:00.000Z"]') 
} 

與此錯誤：

Error: [ngRepeat:dupes] Duplicates in a repeater are not allowed. Use 'track by' expression to specify unique keys. Repeater: inner in activity track by $indexb, Duplicate key: undefined, Duplicate value: 0 

請看一看，並告知有什麼不對。

Answer 1

$indexb無效，因爲它是一個角度定義的屬性。只需使用$index即可。如果你想定義你自己的看到這個：https://docs.angularjs.org/api/ng/directive/ngInit