ERROR 错误:NG0201:在 NodeInjector 中找不到 NgControl 的提供程序

问题描述

我完全没有想法了.我想使用 Reactive Forms Module，所以我将它导入 app.module.ts 中，如

i ran completly out of ideas. I want to user Reactive Forms Module, so i imported it in app.module.ts like

import { ReactiveFormsModule } from '@angular/forms';

@NgModule({
  declarations: [
    AppComponent,
    ...
  ],
  imports: [
    ...
    ReactiveFormsModule,
    ...
  ],
  providers: [],
  bootstrap: [AppComponent]
})

在我的组件中我定义了:

In my Component i defined:

import { Component, OnInit} from "@angular/core";

import { FormControl, FormGroup } from '@angular/forms';

@Component({
    ...
})

export class SearchComponent implements OnInit{
    //Variablen
    form: FormGroup;

    //Konstruktor
    constructor(){}

    //Methoden
    ngOnInit(){
        this.form = new FormGroup({
            'title': new FormControl(null)
        });
    }

    showValue(){
        console.log(this.form.get('title'));
    }
}

编译运行良好，但在显示时崩溃，并在浏览器控制台中显示以下错误:core.js:6156 ERROR 错误:NG0201:在 NodeInjector 中找不到 NgControl 的提供程序."

Compiling works well, but when displaying it it crashes with the error below shown in the Browser Console:"core.js:6156 ERROR Error: NG0201: No provider for NgControl found in NodeInjector."

你们中有人知道出了什么问题吗?

Does anybody of you has an idea what went wrong?

我真的很感激任何提示.

I would really appreciate any hint.

非常感谢！

推荐答案

要完成这项工作，您必须在 @NgModule 中导入 ReactiveFormsModule，正如您的问题所暗示的那样，它是 ViewsModule.因为 FormControl 作为 ReactiveFormsModule 的一部分而不是 FormsModule 公开.

To make this work you'll have to import the ReactiveFormsModule in your @NgModule which is the ViewsModule as your question suggests. As FormControl is exposed as a part of ReactiveFormsModule and NOT the FormsModule.

import { ReactiveFormsModule, ... } from '@angular/forms';

@NgModule({
  imports: [..., ReactiveFormsModule, ...],
  ...
})
export class ViewsModule {...}

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