单击Angular2中的链接时隐藏/显示表格行

请不要将其标记为重复 - 我已经尝试过以下链接：1）Hide/show individual items inside ngFor 2）Angular 2 - expand collapse table row 3）Hide/show individual items inside ngFor in angular 2

问题：
我在点击上一行中的链接时试图隐藏/显示表格行，如下所示： component.html

<div class="table-responsive" *ngFor="let total of totals; let i=index">
<table class="table">
    <ng-container *ngIf="total">   
            <h4 class="productName">Product: {{total.projectGroup}}</h4>
            <tr>
                <th>Total LOC</th>
                <th>Total Test Coverage</th>
                <th>Total Coverage on New Code</th>
                <th>Total Technical Debt</th>
                <th>Total Issues</th>
            </tr>        
            <tr>
                <td>{{total.totalLOC}}</td>
                <td>{{total.totalCoverage}}</td>
                <td>{{total.totalNewCoverage}}</td>
                <td>{{total.totalTechDebtDays}}</td>
                <td><span *ngIf="total.totalCriticalIssues >= 0">Critical: </span>{{total.totalCriticalIssues}} 
 <span *ngIf="total.totalNonCriticalIssues >= 0">Non-critical: </span>{{total.totalNonCriticalIssues}}</td>
            </tr>
            <tr>
                <td><a id="{{i}}" class ="a_link"  (click)="toggle[total.projectGroup]=!toggle[total.projectGroup]; expand(total.projectGroup)"> Expand/Collapse</a></td>
            </tr>
            <tr [hidden]="!toggle[total.projectGroup]">                       
                <div class="table-responsive">
                    <table class="table">
                        <tr class="table-header">
                            <th>Project Key</th>
                            <th>Quality Gate</th>
                            <th>LOC</th>
                            <th>Test Coverage</th>
                            <th>Coverage on New Code</th>
                            <th>Technical Debt</th>
                            <th>Issues</th>
                        </tr>  
                        <tr *ngFor="let pjt of indProjects" class="table-condensed">
                            <td>{{pjt.projectKey}}</td>
                            <td>{{pjt.qualityGate}}</td>
                            <td>{{pjt.loc}}</td>
                            <td>{{pjt.coverage}}</td>
                            <td>{{pjt.newCoverage}}</td>
                            <td>{{pjt.techDebtDays}}</td>
                            <td><span *ngIf="pjt.criticalIssues >= 0">Critical: </span>{{pjt.criticalIssues}} 
 <span *ngIf="pjt.nonCriticalIssues >= 0">Non-critical: </span>{{pjt.nonCriticalIssues}}</td>
                        </tr>
                    </table>
                </div>
            </tr>                
    </ng-container>
</table>

它的工作如果我点击相同的"Expand/Collapse"链接2次 - 首先它显示然后它隐藏 . 但是如果我点击链接一次（显示）然后点击另一个链接，两个扩展都将在内部表中显示相同的数据（这是最后一次扩展的数据） . 我需要的是第一次扩展应显示与该链接相关的数据，第二次扩展应显示与第二次扩展相关的数据 .

请，任何指针都会有所帮助 . 如果我不清楚描述问题，请告诉我 .