Javascript 角度4-类型错误:_co.send不是函数。(在';#co.send($event)';中,';#co.send';未定义)
我正在尝试使用PostgreSQL数据库在Django后端和Angular 4前端之间创建实时聊天。我想在前端输入我自己的文本,按enter键并发送它。我在Angular 4-Javascript 角度4-类型错误:_co.send不是函数。(在';#co.send($event)';中,';#co.send';未定义),javascript,angular,typescript,web,websocket,Javascript,Angular,Typescript,Web,Websocket,我正在尝试使用PostgreSQL数据库在Django后端和Angular 4前端之间创建实时聊天。我想在前端输入我自己的文本,按enter键并发送它。我在Angular 4-TypeError中得到一个错误:_co.send不是一个函数。(在“\u co.send($event)”中,“\u co.send”未定义)。我不确定哪里有问题。你知道怎么了吗 app.component.html: <button (click)="sendMsg()">Send Message</
TypeError中得到一个错误:_co.send不是一个函数。(在“\u co.send($event)”中,“\u co.send”未定义)
。我不确定哪里有问题。你知道怎么了吗
app.component.html:
<button (click)="sendMsg()">Send Message</button>
<h4>Type away! Press [enter] when done.</h4>
<div><key-up3 (keyup7)="send($event)"></key-up3></div>
<h4>Little Tour of Heroes</h4>
<p><i>Add a new hero</i></p>
<div><little-tour></little-tour></div>
发送消息
打字!完成后按[输入]。
小英雄之旅
添加一个新的英雄
app.component.ts:
import { Component } from '@angular/core';
import { WebsocketService } from './websocket.service';
import { ChatService } from './chat.service';
import { Output, EventEmitter } from '@angular/core';
import {enableProdMode} from '@angular/core';
enableProdMode();
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css'],
providers: [ WebsocketService, ChatService ]
})
export class AppComponent {
constructor(private chatService: ChatService) {
chatService.messages.subscribe(msg => {
console.log("Response from websocket: " + msg.message);
});
}
private message = {
message: 'this is a test message'
}
sendMsg() {
console.log('new message from client to websocket: ', this.message);
this.chatService.messages.next(this.message);
this.message.message = 'this is a test message2';
}
}
@Component({
selector: 'key-up3',
template: `
<input #box (keyup.enter)="keyup7.emit(box.value)">
<p>{{value}}</p>
`
})
export class KeyUpComponent_v3 {
@Output() keyup7 = new EventEmitter<string>();
}
从'@angular/core'导入{Component};
从“./websocket.service”导入{WebsocketService};
从“./chat.service”导入{ChatService};
从“@angular/core”导入{Output,EventEmitter};
从“@angular/core”导入{enableProdMode};
enableProdMode();
@组成部分({
选择器:'应用程序根',
templateUrl:“./app.component.html”,
样式URL:['./app.component.css'],
提供者:[WebsocketService,ChatService]
})
导出类AppComponent{
构造函数(专用聊天室服务:聊天室服务){
chatService.messages.subscribe(msg=>{
日志(“来自websocket的响应:“+msg.message”);
});
}
私人消息={
消息:“这是一条测试消息”
}
sendMsg(){
console.log('从客户端到websocket的新消息:',this.message);
this.chatService.messages.next(this.message);
this.message.message='这是一条测试消息2';
}
}
@组成部分({
选择器:'key-up3',
模板:`
{{value}}
`
})
导出类KeyUpComponent\u v3{
@Output()keyup7=新的EventEmitter();
}
websocket.service.ts:
import { Injectable } from '@angular/core';
import * as Rx from 'rxjs/Rx';
@Injectable()
export class WebsocketService {
constructor() { }
private subject: Rx.Subject<MessageEvent>;
public connect(url): Rx.Subject<MessageEvent> {
if (!this.subject) {
this.subject = this.create(url);
console.log("Successfully connected: " + url);
}
return this.subject;
}
private create(url): Rx.Subject<MessageEvent> {
let ws = new WebSocket(url);
let observable = Rx.Observable.create(
(obs: Rx.Observer<MessageEvent>) => {
ws.onmessage = obs.next.bind(obs);
ws.onerror = obs.error.bind(obs);
ws.onclose = obs.complete.bind(obs);
return ws.close.bind(ws);
})
let observer = {
next: (data: Object) => {
if (ws.readyState === WebSocket.OPEN) {
ws.send(JSON.stringify(data));
}
}
}
return Rx.Subject.create(observer, observable);
}
}
import { Injectable } from '@angular/core';
import { Observable, Subject } from 'rxjs/Rx';
import { WebsocketService } from './websocket.service';
const CHAT_URL = 'ws://localhost:8000/';
export interface Message {
message: string
}
@Injectable()
export class ChatService {
public messages: Subject<Message>;
constructor(wsService: WebsocketService) {
this.messages = <Subject<Message>>wsService
.connect(CHAT_URL)
.map((response: MessageEvent): Message => {
let data = JSON.parse(response.data);
return {
message: data.message
}
});
}
}
从'@angular/core'导入{Injectable};
从“rxjs/Rx”导入*作为Rx;
@可注射()
导出类WebsocketService{
构造函数(){}
私人科目:接收科目;
公共连接(url):Rx.Subject{
如果(!this.subject){
this.subject=this.create(url);
log(“成功连接:+url”);
}
返回此.subject;
}
私有创建(url):Rx.Subject{
设ws=newwebsocket(url);
让可观察=Rx.observable.create(
(obs:Rx.Observer)=>{
ws.onmessage=obs.next.bind(obs);
ws.onerror=obs.error.bind(obs);
ws.onclose=obs.complete.bind(obs);
返回ws.close.bind(ws);
})
让观察者={
下一步:(数据:对象)=>{
if(ws.readyState==WebSocket.OPEN){
send(JSON.stringify(data));
}
}
}
返回Rx.Subject.create(观察者、可观察者);
}
}
chat.service.ts:
import { Injectable } from '@angular/core';
import * as Rx from 'rxjs/Rx';
@Injectable()
export class WebsocketService {
constructor() { }
private subject: Rx.Subject<MessageEvent>;
public connect(url): Rx.Subject<MessageEvent> {
if (!this.subject) {
this.subject = this.create(url);
console.log("Successfully connected: " + url);
}
return this.subject;
}
private create(url): Rx.Subject<MessageEvent> {
let ws = new WebSocket(url);
let observable = Rx.Observable.create(
(obs: Rx.Observer<MessageEvent>) => {
ws.onmessage = obs.next.bind(obs);
ws.onerror = obs.error.bind(obs);
ws.onclose = obs.complete.bind(obs);
return ws.close.bind(ws);
})
let observer = {
next: (data: Object) => {
if (ws.readyState === WebSocket.OPEN) {
ws.send(JSON.stringify(data));
}
}
}
return Rx.Subject.create(observer, observable);
}
}
import { Injectable } from '@angular/core';
import { Observable, Subject } from 'rxjs/Rx';
import { WebsocketService } from './websocket.service';
const CHAT_URL = 'ws://localhost:8000/';
export interface Message {
message: string
}
@Injectable()
export class ChatService {
public messages: Subject<Message>;
constructor(wsService: WebsocketService) {
this.messages = <Subject<Message>>wsService
.connect(CHAT_URL)
.map((response: MessageEvent): Message => {
let data = JSON.parse(response.data);
return {
message: data.message
}
});
}
}
从'@angular/core'导入{Injectable};
从'rxjs/Rx'导入{可观察,主题};
从“./websocket.service”导入{WebsocketService};
const CHAT_URL='ws://localhost:8000/';
导出接口消息{
消息:string
}
@可注射()
出口类聊天室服务{
公共信息:主题;
构造函数(wsService:WebsocketService){
this.messages=wsService
.connect(聊天室URL)
.map((响应:MessageEvent):Message=>{
让data=JSON.parse(response.data);
返回{
message:data.message
}
});
}
}
您有sendMsg
功能,但组件中缺少send
功能?在app.component.ts:
中有sendMsg()
。我不知道你的意思是什么?但是你也在调用(keyup7)=“send($event)”
,这是未定义的。如果还没有定义,请检查。