ng-bootstrap ngbDropdown not working in angular 4

Question

At my angular 4 application is the ngbDropdown-Element from ng-bootstrap not working.

I have installed the following npm modules for this case:

"@ng-bootstrap/ng-bootstrap": "^1.0.0-alpha.22", "bootstrap": "4.0.0-alpha.6", "bootstrap-sass": "^3.3.7",

My app.module.ts is looking like this:

import { BrowserModule } from "@angular/platform-browser"
import { NgModule } from "@angular/core";
import { FormsModule } from "@angular/forms";
import { HttpModule } from "@angular/http";

import { AppComponent } from "./app.component";
import { FileitHeaderComponent } from "./fileit-header/fileit-header.component";
import {TranslateModule} from "ng2-translate";
import { CCACampaignComponent } from "./cca-campaign/cca-campaign.component";
import {NgbModule} from "@ng-bootstrap/ng-bootstrap";


@NgModule({
  declarations: [
    AppComponent,
    FileitHeaderComponent,
    CCACampaignComponent
  ],
  imports: [
    BrowserModule,
    FormsModule,
    HttpModule,
    TranslateModule.forRoot(),
    NgbModule.forRoot()
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

And in the CCA Campaign I am trying to use the Demo of ng-bootstrap:

<div ngbDropdown class="d-inline-block">
    <button class="btn btn-outline-primary" id="dropdownMenu1" ngbDropdownToggle>Toggle dropdown</button>
        <div class="dropdown-menu" aria-labelledby="dropdownMenu1">
            <button class="dropdown-item">Action - 1</button>
            <button class="dropdown-item">Another Action</button>
            <button class="dropdown-item">Something else is here</button>
        </div>
</div>

But the result of this code is unfortunately very bad:

and nothing happens when I click on it ...

Answer 1

@Philipp Just make a minor change to your HTML code:

<div ngbDropdown class="d-inline-block">
    <button class="btn btn-outline-primary" id="dropdownMenu1" ngbDropdownToggle>Toggle dropdown</button>
        <div class="dropdown-menu" aria-labelledby="dropdownMenu1" ngbDropdownMenu>
            <button class="dropdown-item">Action - 1</button>
            <button class="dropdown-item">Another Action</button>
            <button class="dropdown-item">Something else is here</button>
        </div>
</div>

ngbDropdownMenu is property added to "dropdown-menu" div.

Answer 2

tl;dr; install Bootstrap 4 CSS.

ng-bootstrap requires Bootstrap 4 as documented on the "Getting Started" page. For some reason you've got "bootstrap-sass": "^3.3.7" so it looks like you are mixing Bootstrap versions and might be using Bootstrap 3, effectively.

With the Bootstrap 4 CSS things work perfectly fine as shown on the demo page (and plunkers you can fork from it): https://ng-bootstrap.github.io/#/components/dropdown