Ionic framework 错误：未捕获（承诺中）：NullInjectorError:R3InjectorError（RegisterManagementModule）[AccessProviders->；AccessProviders]

我在

register.page.ts

中使用AngularJS的Ionic应用程序中遇到问题；当我要在项目中添加

AccessProviders

路径时，项目会显示：

错误：Uncaught（承诺中）：NullInjectorError:R3InjectorError（registermanagemodule）[AccessProviders->AccessProviders->AccessProviders->AccessProviders->AccessProviders]：NullInjectorError:AccessProviders没有提供程序

我已手动创建access providers文件夹和文件。

注册.page.ts

import {Router} from "@angular/router";
import { ToastController, LoadingController, AlertController } from "@ionic/angular";
import {AccessProviders} from "../../providers/access-providers";

@Component({
  selector: 'app-register',
  templateUrl: './register.page.html',
  styleUrls: ['./register.page.scss'],
})
export class RegisterPage implements OnInit {

    name: string = "";
    gender: string = "";
    dob: string = "";
    email: string = "";
    password: string = "";
    confirm_password: string = "";
    disabledButton;

  constructor(
      private router: Router,
      private toastCtrl: ToastController,
      private alertCtrl: AlertController,
      private loadingCtrl: LoadingController,
      private accsPrvds: AccessProviders,
  ) { }

  ionViewDidEnter() {
      this.disabledButton = false;
  }

import { HttpClient, HttpHeaders, HttpErrorResponse } from "@angular/common/http";
import  'rxjs/add/operator/map';
import  'rxjs/add/operator/timeout';

@Injectable()
export class AccessProviders {
    server: string = 'http://localhost:8100/register'; //should change.

    constructor(
        public http: HttpClient
    ) {

    }

    postData(body, file) {
        let headers = new HttpHeaders({
            'Content-Type': 'application/json; charset=UTF-8'
        });

        let options = {
            headers: headers
        };

        return this.http.post(this.server + file, JSON.stringify(body), options)
            .timeout(59000)// 59 sec timeout
            .map(res => res);
    }
}

访问提供商。ts

import {Router} from "@angular/router";
import { ToastController, LoadingController, AlertController } from "@ionic/angular";
import {AccessProviders} from "../../providers/access-providers";

@Component({
  selector: 'app-register',
  templateUrl: './register.page.html',
  styleUrls: ['./register.page.scss'],
})
export class RegisterPage implements OnInit {

    name: string = "";
    gender: string = "";
    dob: string = "";
    email: string = "";
    password: string = "";
    confirm_password: string = "";
    disabledButton;

  constructor(
      private router: Router,
      private toastCtrl: ToastController,
      private alertCtrl: AlertController,
      private loadingCtrl: LoadingController,
      private accsPrvds: AccessProviders,
  ) { }

  ionViewDidEnter() {
      this.disabledButton = false;
  }

import { HttpClient, HttpHeaders, HttpErrorResponse } from "@angular/common/http";
import  'rxjs/add/operator/map';
import  'rxjs/add/operator/timeout';

@Injectable()
export class AccessProviders {
    server: string = 'http://localhost:8100/register'; //should change.

    constructor(
        public http: HttpClient
    ) {

    }

    postData(body, file) {
        let headers = new HttpHeaders({
            'Content-Type': 'application/json; charset=UTF-8'
        });

        let options = {
            headers: headers
        };

        return this.http.post(this.server + file, JSON.stringify(body), options)
            .timeout(59000)// 59 sec timeout
            .map(res => res);
    }
}

我如何解决这个问题？我希望得到我的答案。
在您的
访问提供程序.ts
文件中添加blow代码：

import { Injectable } from '@angular/core'; // at top

@Injectable({
  providedIn: 'root' // just before your class
})
export class AccessProviders {}

看起来您需要将其添加到app.modules.ts文件的providers下

如果您只需要在一个页面中使用该类，则可以将其添加到相应页面的page.module.ts文件中。
确保
HttpClientModule
在
AppModule
级别注册。
我遇到了类似的问题，我在这里找到了解决方案：

我必须进口
“从“@angular/common/http”；”导入{HttpClientModule}”
导入：[HttpClientModule]，在引用组件的模块内。
在应用程序模块中

您必须在顶部添加：

import {AccessProviders} from "../../providers/access-providers";

在同一个文件上，找到提供者，只需将AccessProviders添加到提供者列表中