如何使用 observables 在 electron ipcMain 和 angular ipcRenderer 之间异步发送数据

Question

我有一个 ipcMain 和 ipcRenderer 进程（电子和角度的一面）。 如何重写我的代码以便从主进程异步接收数据？ 使用 typeorm 连接到数据库

渲染器端（data.service.ts）：

constructor(private _electronService: ElectronService) {}

getItems(): Observable<Item[]> {
    return of(this._electronService.ipcRenderer.sendSync('get-items')).pipe(
      catchError((error: any) => Observable.throw(error.json))
    );
}

应用程序组件.ts

@Component({
  selector: 'App',
  template: `<div style="text-align:center">
    <h1>
        Welcome to {{ title }}!
    </h1>
    <h2>Here is the contents of the database: </h2>
    <div>
        <ul style="list-style: none">
            <li *ngFor="let item of itemList">
                {{ item.name }}
            </li>
        </ul>
    </div>
</div>`
})

export class AppComponent implements OnInit {
  itemList: Item[];

  constructor(private appservice: AppService) {}

  ngOnInit(): void {
    console.log('component initialized');
    this.appservice.getItems().subscribe((items) => (this.itemList = items));
  }

主端（index.ts）：

import { app, BrowserWindow, ipcMain } from 'electron';

import { createConnection } from 'typeorm';

import { Item} from './assets/model/item.schema';

const createWindow = async () => {
  const connection = await createConnection({
    type: 'mssql',
    host: 'server\\instance',
    username: 'sa',
    password: 'password',
    port: 1433,
    database: 'test',
    synchronize: true,
    logging: true,
    entities: [ Item ],
  });

  const itemRepo = connection.getRepository(Item);

  ipcMain.on('get-items', async (event: any, ...args: any[]) => {
    try {
      event.returnValue = await itemRepo.find();
    } catch (err) {
      throw err;
    }
  });

Answer 1

这对我有用：

data.service.ts（角度）

import { Injectable } from '@angular/core';
import { IpcRenderer } from 'electron';
import { Observable } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class DataService {
  private ipc: IpcRenderer;

  constructor() { 
    if ((<any>window).require) {
      try {
        this.ipc = (<any>window).require('electron').ipcRenderer
      } catch (error) {
        throw error;
      }
    } else {
      console.warn('Could not load electron ipc');
    }
  }

  getData() {
    return new Observable<any>(observer => {
      this.ipc.once('getDataResponse', (event, arg) => {
        observer.next(arg);
      });

      this.ipc.send('getData');
    });
  }
}

main.ts（电子）

import { app, BrowserWindow, ipcMain } from 'electron';
import * as path from 'path';
import * as url from 'url';

let win: BrowserWindow;

app.on('ready', createWindow)

app.on('activate', () => {
    if (win === null) {
        createWindow();
    }
});

function createWindow() {
    win = new BrowserWindow({ 
        width: 800, 
        height: 600,
        frame: false,
        webPreferences: {
            nodeIntegration: true // <-- important
        }
    });

    win.loadURL(
        url.format({
          pathname: path.join(__dirname, `/../../dist/myApp/index.html`),
          protocol: 'file:',
          slashes: true,
        })
    );

    win.webContents.openDevTools();

    win.on('closed', () => {
        win = null;
    });
}

ipcMain.on('getData', (event, args) => {
    event.reply('getDataResponse', {
        data: [
            {
                name: 'test'
            }
        ]
    });
});