Javascript Angular 模式对话框不起作用并隐藏按钮页脚

我正在使用ANGLE创建一个基本的Web应用程序.我想创建3列Scrum板.

在第一篇专栏文章中，我想创建一个按钮，只要您单击它，就会打开一个模式对话框.问题是，一旦将模式对话框实现到按钮中，按钮就变得不可见，甚至页脚也消失了.

以下是所有内容:

body.component.html:

<div class="board-container">
    <div class="column" id="offen">
        <app-task-form></app-task-form>
    </div>
    <div class="column" id="bearbeitung">
        <!-- Hier kommen Aufgaben in der Kategorie "In Bearbeitung" -->
    </div>
    <div class="column" id="abgeschlossen">
        <!-- Hier kommen Aufgaben in der Kategorie "Abgeschlossen" -->
    </div>

task-form.component.html:

<input type="text" [(ngModel)]="taskTitle" placeholder="Enter task title" />
<button mat-raised-button (click)="openModal()">Open Modal</button>

task-form.component.ts:

import { Component } from '@angular/core';
import { MatDialog } from '@angular/material/dialog';

import { ModalComponent } from '../modal/modal.component';

@Component({
  selector: 'app-task-form',
  templateUrl: './task-form.component.html',
  styleUrls: ['./task-form.component.css']
})
export class TaskFormComponent {
  taskTitle: string = ''; // Eine Eigenschaft, um den Aufgabentitel zu speichern

  constructor(public dialog: MatDialog) {}

  openModal() {
    this.dialog.open(ModalComponent);
  }
}

modal.component.ts:

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

@Component({
  selector: 'app-modal',
  templateUrl: './modal.component.html',
  styleUrls: ['./modal.component.css']
})
export class ModalComponent {

}

app.module.ts:

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms'; // Importiere FormsModule


import { AppRoutingModule } from './app-routing.module';
import { AppComponent } from './app.component';
import { HeaderComponent } from './header/header.component';
import { BodyComponent } from './body/body.component';
import { FooterComponent } from './footer/footer.component';
import { TaskFormComponent } from './task-form/task-form.component';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { ModalComponent } from './modal/modal.component';

@NgModule({
  declarations: [
    AppComponent,
    HeaderComponent,
    BodyComponent,
    FooterComponent,
    TaskFormComponent,
    ModalComponent
    ],
  imports: [
    BrowserModule,
    AppRoutingModule,
    FormsModule, // Füge FormsModule hinzu
    BrowserAnimationsModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }