Question

我有一个有服务的组件注入它的构造函数，我在对象数组上有一个map函数。当我尝试在map函数中访问我的模型时，它返回了未定义的错误。

代码：

export class StrategyComponent implements ComponentDefinition{
type = "component";
strategies : any[];

constructor(@Inject(GateDataModel) private gateDataModel){
   //Updatedcode
   EmitterService.get("event_name")
        .subscribe(obj => {
            this.buildStrategies(obj.strategies);
        })
}


buildStrategies(_strategies){
    this.strategies = _strategies;
}

selectStrategy(i){ //Function called on click from template
    this.gateDataModel.strategyId = this.strategies[i].id;
    this.strategies.map(function(_strategy, index){
        this.gateDataModel.strategyId = _strategy.id; //Error Here
        i === index ? _strategy.isSelected = true : _strategy.isSelected = false;
    })
}


}

如何在地图功能中访问我的模型？

由于

Answer 1

正如我在评论中提到的，我非常确定问题在于调用＆＃39; 这个 .gateDataModel.strategyId＆＃39;在回电里面。无法在该范围内解析this。您有两种选择：

陷阱this就像这样：


selectStrategy(i){ //Function called on click from template
    this.gateDataModel.strategyId = this.strategies[i].id;
    var _this = this;
    this.strategies.map(function(_strategy, index){
        _this.gateDataModel.strategyId = _strategy.id; //Error Here
        i === index ? _strategy.isSelected = true : _strategy.isSelected = false;
    })
}

您可以使用~~函数指针~~箭头函数表达式代替：


selectStrategy(i){ //Function called on click from template
    this.gateDataModel.strategyId = this.strategies[i].id;
    this.strategies.map((_strategy, index) => {
        this.gateDataModel.strategyId = _strategy.id; //Error Here
        i === index ? _strategy.isSelected = true : _strategy.isSelected = false;
    }) // You might need to check my syntax
}

访问foreach中的注入服务 - angular2

1 个答案: