要在Angular 7中创建一个递归对象表格行，可以使用递归组件的概念。以下是一个解决方案的代码示例：

1. 创建一个名为recursive-table-row的递归组件：

recursive-table-row.component.ts：

import { Component, Input } from '@angular/core';

@Component({
  selector: 'recursive-table-row',
  templateUrl: './recursive-table-row.component.html',
  styleUrls: ['./recursive-table-row.component.css']
})
export class RecursiveTableRowComponent {
  @Input() rowData: any;
  @Input() columns: string[];

  hasChildren(): boolean {
    return this.rowData.children && this.rowData.children.length > 0;
  }
}

recursive-table-row.component.html：

  {{rowData[column]}}


  
    
  

2. 在父组件中使用递归组件：

parent.component.ts：

import { Component } from '@angular/core';

@Component({
  selector: 'app-parent',
  templateUrl: './parent.component.html',
  styleUrls: ['./parent.component.css']
})
export class ParentComponent {
  data = [
    { name: 'John', age: 30, children: [
      { name: 'Alice', age: 5, children: [] },
      { name: 'Bob', age: 10, children: [
        { name: 'Charlie', age: 3, children: [] },
        { name: 'David', age: 7, children: [] }
      ] }
    ] },
    { name: 'Mary', age: 25, children: [] }
  ];

  columns = ['name', 'age'];
}

parent.component.html：

  

    

      
{{column}}
    
  
  

    

      
    
  

3. 在模块中引入递归组件：

app.module.ts：

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { AppComponent } from './app.component';
import { RecursiveTableRowComponent } from './recursive-table-row/recursive-table-row.component';
import { ParentComponent } from './parent/parent.component';

@NgModule({
  declarations: [
    AppComponent,
    RecursiveTableRowComponent,
    ParentComponent
  ],
  imports: [
    BrowserModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

这样，当你在父组件中使用标签时，就会生成一个递归的对象表格。