map data yet available

 function init() {  
        map = new esri.Map("map", {  
          basemap: "topo", // 指定的地图底图.有效选项:"streets","satellite","hybrid","topo","gray","oceans","national-geographic","osm".  
          center: [116.4012,39.902],   // 居中的经纬度  修改为北京的经纬度后(第一个参数是经度,第二个参数是纬度)
          //center: [-122.445, 37.752],   // 居中的经纬度  
          zoom: 14  // 缩放深度级别  
        });  



  

修改过为北京的经纬度后,变成了

原因是zoom的级别过大,将它改小,就可以正常显示,或者将api换成3.7,也可以成功显示结果



这是我CloseEventClass.ts的代码: import { Event2 } from './Event'; export class CloseEvent2 extends Event2 implements CloseEvent { readonly code: number; readonly reason: string; readonly wasClean: boolean; constructor(type: string, { code, reason }: CloseEventInit = {}) { super(type); this.code = code || 0; this.reason = reason || ''; this.wasClean = this.code === 0; } } export const CloseEventClass = typeof CloseEvent !== 'undefined' ? CloseEvent : CloseEvent2; 这是我ErrorEventClass.ts的代码: import { Event2 } from './Event'; export class ErrorEvent2 extends Event2 implements ErrorEvent { readonly colno: number; readonly error: any; readonly filename: string; readonly lineno: number; readonly message: string; constructor(type: string, { colno, error, filename, lineno, message }: ErrorEventInit = {}) { super(type); this.error = error; this.colno = colno || 0; this.filename = filename || ''; this.lineno = lineno || 0; this.message = message || ''; } } export const ErrorEventClass = typeof ErrorEvent !== 'undefined' ? ErrorEvent : ErrorEvent2; 这是我MessageEventClass.ts的代码: import { Event2 } from './Event'; export class MessageEvent2 extends Event2 implements MessageEvent { public readonly data: any; public readonly origin: string; public readonly lastEventId: string; public readonly source: any; public readonly ports: ReadonlyArray<any>; constructor( type: string, { data = null, origin = '', lastEventId = '', source = null, ports = [] }: MessageEventInit = {}, ) { super(type); this.data = data; this.origin = `${origin}`; this.lastEventId = `${lastEventId}`; this.source = source; this.ports = [...ports]; } initMessageEvent(): void { throw Error('Deprecated method'); } } export const MessageEventClass = typeof MessageEvent !== 'undefined' ? MessageEvent : MessageEvent2; 这是我Multiplexer.ts的代码: import { TypedEmitter } from '../../common/TypedEmitter'; import { Message } from './Message'; import { MessageType } from './MessageType'; import { EventClass } from './Event'; import { CloseEventClass } from './CloseEventClass'; import { ErrorEventClass } from './ErrorEventClass'; import { MessageEventClass } from './MessageEventClass'; import Util from '../../app/Util'; interface MultiplexerEvents extends WebSocketEventMap { empty: Multiplexer; channel: { channel: Multiplexer; data: ArrayBuffer }; open: Event; close: CloseEvent; message: MessageEvent; } export interface WebsocketEventEmitter { dispatchEvent(event: Event): boolean; addEventListener<K extends keyof WebSocketEventMap>( type: K, listener: (this: WebSocket, ev: WebSocketEventMap[K]) => any, options?: boolean | AddEventListenerOptions, ): void; removeEventListener<K extends keyof WebSocketEventMap>( type: K, listener: (this: WebSocket, ev: WebSocketEventMap[K]) => any, options?: boolean | EventListenerOptions, ): void; } export class Multiplexer extends TypedEmitter<MultiplexerEvents> implements WebSocket { readonly CONNECTING = 0; readonly OPEN = 1; readonly CLOSING = 2; readonly CLOSED = 3; public binaryType: BinaryType = 'blob'; public readyState: number; private channels: Map<number, { channel: Multiplexer; emitter: WebsocketEventEmitter }> = new Map(); private nextId = 0; private maxId = 4294967296; private storage: Array<string | ArrayBufferLike | Blob | ArrayBufferView> = []; private readonly messageEmitter: WebsocketEventEmitter; private emptyTimerScheduled = false; public onclose: ((this: WebSocket, ev: CloseEvent) => any) | null = null; public onerror: ((this: WebSocket, ev: Event) => any) | null = null; public onmessage: ((this: WebSocket, ev: MessageEvent) => any) | null = null; public onopen: ((this: WebSocket, ev: Event) => any) | null = null; public url = ''; public static wrap(ws: WebSocket): Multiplexer { return new Multiplexer(ws); } protected constructor(public readonly ws: WebSocket, private _id = 0, emitter?: WebsocketEventEmitter) { super(); this.readyState = this.CONNECTING; if (this._id === 0) { ws.binaryType = 'arraybuffer'; this.readyState = this.ws.readyState; } this.messageEmitter = emitter || ws; const onOpenHandler = (event: Event) => { this.readyState = this.ws.readyState; this.dispatchEvent(event); }; const onCloseHandler = (event: CloseEvent) => { this.readyState = this.ws.readyState; this.dispatchEvent(event); this.channels.clear(); }; const onErrorHandler = (event: Event) => { this.readyState = this.ws.readyState; this.dispatchEvent(event); this.channels.clear(); }; const onMessageHandler = (event: MessageEvent) => { const { data } = event; const message = Message.parse(data); switch (message.type) { case MessageType.CreateChannel: { const { channelId, data } = message; if (this.nextId < channelId) { this.nextId = channelId; } const channel = this._createChannel(channelId, false); this.emit('channel', { channel, data }); break; } case MessageType.RawStringData: { const data = this.channels.get(message.channelId); if (data) { const { channel } = data; const msg = new MessageEventClass('message', { data: Util.utf8ByteArrayToString(Buffer.from(message.data)), lastEventId: event.lastEventId, origin: event.origin, source: event.source, }); channel.dispatchEvent(msg); } else { console.error(`Channel with id (${message.channelId}) not found`); } break; } case MessageType.RawBinaryData: { const data = this.channels.get(message.channelId); if (data) { const { channel } = data; const msg = new MessageEventClass('message', { data: message.data, lastEventId: event.lastEventId, origin: event.origin, source: event.source, }); channel.dispatchEvent(msg); } else { console.error(`Channel with id (${message.channelId}) not found`); } break; } case MessageType.Data: { const data = this.channels.get(message.channelId); if (data) { const { emitter } = data; const msg = new MessageEventClass('message', { data: message.data, lastEventId: event.lastEventId, origin: event.origin, source: event.source, }); emitter.dispatchEvent(msg); } else { console.error(`Channel with id (${message.channelId}) not found`); } break; } case MessageType.CloseChannel: { const data = this.channels.get(message.channelId); if (data) { const { channel } = data; channel.readyState = channel.CLOSING; try { channel.dispatchEvent(message.toCloseEvent()); } finally { channel.readyState = channel.CLOSED; } } else { console.error(`Channel with id (${message.channelId}) not found`); } break; } default: const error = new Error(`Unsupported message type: ${message.type}`); this.dispatchEvent(new ErrorEventClass('error', { error })); } }; const onThisOpenHandler = () => { if (!this.storage.length) { return; } const ws = this.ws; if (ws instanceof Multiplexer) { this.storage.forEach((data) => ws.sendData(data)); } else { this.storage.forEach((data) => ws.send(data)); } this.storage.length = 0; }; const onThisCloseHandler = () => { ws.removeEventListener('open', onOpenHandler); ws.removeEventListener('error', onErrorHandler); ws.removeEventListener('close', onCloseHandler); this.messageEmitter.removeEventListener('message', onMessageHandler); this.off('close', onThisCloseHandler); this.off('open', onThisOpenHandler); }; ws.addEventListener('open', onOpenHandler); ws.addEventListener('error', onErrorHandler); ws.addEventListener('close', onCloseHandler); this.messageEmitter.addEventListener('message', onMessageHandler); this.on('close', onThisCloseHandler); this.on('open', onThisOpenHandler); this.scheduleEmptyEvent(); } public get bufferedAmount(): number { return 0; } public get extensions(): string { return ''; } public get protocol(): string { return ''; } public get id(): number { return this._id; } private scheduleEmptyEvent(): void { if (this.emptyTimerScheduled) { return; } this.emptyTimerScheduled = true; Promise.resolve().then(() => { if (this.emptyTimerScheduled) { this.emptyTimerScheduled = false; this.emit('empty', this); } }); } private clearEmptyEvent(): void { if (this.emptyTimerScheduled) { this.emptyTimerScheduled = false; } } public close(code = 1000, reason?: string): void { if (this.readyState === this.CLOSED || this.readyState === this.CLOSING) { return; } if (this._id) { this.readyState = this.CLOSING; try { const message = Message.fromCloseEvent(this._id, code, reason).toBuffer(); if (this.ws instanceof Multiplexer) { this.ws.sendData(message); } else { this.ws.send(message); } this.emit('close', new CloseEventClass('close', { code, reason })); } finally { this.readyState = this.CLOSED; } } else { this.ws.close(code, reason); } } // public send(data: string | ArrayBufferLike | Blob | ArrayBufferView): void { // if (this.ws instanceof Multiplexer) { // if (typeof data === 'string') { // data = Message.createBuffer(MessageType.RawStringData, this._id, Buffer.from(data)); // } else { // data = Message.createBuffer(MessageType.RawBinaryData, this._id, Buffer.from(data)); // } // } // this._send(data); // } public send(data: string | ArrayBuffer | Blob | ArrayBufferView): void { let out: string | ArrayBuffer | Blob | ArrayBufferView; if (typeof data === 'string') { out = data; } else if (data instanceof ArrayBuffer) { out = data; } else if (ArrayBuffer.isView(data)) { // 修改此处不要转换为 Buffer out = (data as ArrayBufferView); } else { out = data; // Blob 或其他合法类型 } this.ws.send(out); } // public sendData(data: string | ArrayBufferLike | Blob | ArrayBufferView): void { // if (this.ws instanceof Multiplexer) { // data = Message.createBuffer(MessageType.Data, this._id, Buffer.from(data)); // } // this._send(data); // } public sendData(data: string | ArrayBufferLike | Blob | ArrayBufferView): void { if (this.ws instanceof Multiplexer) { let buf: Buffer; if (typeof data === 'string') { buf = Message.createBuffer(MessageType.Data, this._id, Buffer.from(data)); } else if (data instanceof ArrayBuffer) { buf = Message.createBuffer(MessageType.Data, this._id, Buffer.from(data)); } else if (ArrayBuffer.isView(data)) { buf = Message.createBuffer(MessageType.Data, this._id, Buffer.from(data.buffer, data.byteOffset, data.byteLength)); } else if (data instanceof Blob) { // Blob 需要异步读取,可以暂时 throw 或转换为 ArrayBuffer throw new Error('Blob not supported yet'); } else { // 保护代码 throw new Error('Unsupported data type'); } data = buf; } this._send(data); } private _send(data: string | ArrayBufferLike | Blob | ArrayBufferView): void { const { readyState } = this; if (readyState === this.OPEN) { if (this.ws instanceof Multiplexer) { this.ws.sendData(data); } else { this.ws.send(data); } } else if (readyState === this.ws.CONNECTING) { this.storage.push(data); } else { throw Error(`Socket is already in CLOSING or CLOSED state.`); } } private _createChannel(id: number, sendOpenEvent: boolean): Multiplexer { const emitter = new TypedEmitter<MultiplexerEvents>(); const channel = new Multiplexer(this, id, emitter); this.channels.set(id, { channel, emitter }); if (sendOpenEvent) { if (this.readyState === this.OPEN) { Util.setImmediate(() => { channel.readyState = this.OPEN; channel.dispatchEvent(new EventClass('open')); }); } } else { channel.readyState = this.readyState; } channel.addEventListener('close', () => { this.channels.delete(id); if (!this.channels.size) { this.scheduleEmptyEvent(); } }); this.clearEmptyEvent(); return channel; } public createChannel(data: Buffer): Multiplexer { if (this.readyState === this.CLOSING || this.readyState === this.CLOSED) { throw Error('Incorrect socket state'); } const id = this.getNextId(); const channel = this._createChannel(id, true); this.sendData(Message.createBuffer(MessageType.CreateChannel, id, data)); return channel; } private getNextId(): number { let hitTop = false; while (this.channels.has(++this.nextId)) { if (this.nextId === this.maxId) { if (hitTop) { throw Error('No available id'); } this.nextId = 0; hitTop = true; } } return this.nextId; } public dispatchEvent(event: Event): boolean { if (event.type === 'close' && typeof this.onclose === 'function') { Reflect.apply(this.onclose, this, [event]); } if (event.type === 'open' && typeof this.onopen === 'function') { Reflect.apply(this.onopen, this, [event]); } if (event.type === 'message' && typeof this.onmessage === 'function') { Reflect.apply(this.onmessage, this, [event]); } if (event.type === 'error' && typeof this.onerror === 'function') { Reflect.apply(this.onerror, this, [event]); } return super.dispatchEvent(event); } } 问题出在哪里,怎么解决
最新发布
07-25
<think>我们面临的核心问题是自定义事件类(如CloseEvent2, ErrorEvent2等)在实现标准Event接口时,出现了类型不兼容错误,具体表现在`NONE`属性上(标准接口要求`NONE`为字面量类型`0`,而自定义类中为`number`类型)。此外,在Multiplexer.ts等文件中使用这些自定义事件类时,也出现了类型不匹配的错误。 解决方案思路: 1. 理解标准事件接口:在TypeScript中,标准事件接口(如CloseEvent, ErrorEvent, MessageEvent)定义在lib.dom.d.ts中。其中,`Event`接口有一个静态属性`NONE`,其类型为`0`(字面量类型)。 2. 自定义事件类的问题:我们自定义的事件类(如CloseEvent2)可能将`NONE`定义为`number`类型,导致无法满足标准接口的要求。 3. 修正方法:将自定义事件类中的`NONE`属性类型改为`0`(字面量类型),以匹配标准接口。 具体步骤: 步骤1:修改自定义事件类(CloseEventClass.ts, ErrorEventClass.ts, MessageEventClass.ts等) 例如,在CloseEventClass.ts中: 原代码可能类似: export class CloseEvent2 implements CloseEvent { public static NONE = 0; // ... 其他属性和方法 } 修改为: export class CloseEvent2 implements CloseEvent { public static readonly NONE: 0 = 0; // 明确指定为字面量类型0 // ... 其他属性和方法 } 同样,对ErrorEvent2、MessageEvent2等自定义事件类进行同样的修改。 步骤2:检查其他可能不兼容的属性 除了`NONE`属性,还需要确保其他属性和方法与标准接口一致。例如,`CloseEvent`接口有`code`、`reason`、`wasClean`等属性。确保自定义类中这些属性的类型与接口一致。 步骤3:重新编译,检查错误是否消除 如果按照上述修改后,类型错误应该会消失。因为现在自定义事件类的`NONE`属性类型与标准接口一致(都是`0`)。 深入分析: 为什么会出现这个错误? 在TypeScript中,接口的实现要求严格匹配。标准接口`CloseEvent`中,`NONE`是静态属性,且类型为`0`(字面量类型)。而自定义类中如果定义为`number`,虽然0是number的子类型,但静态属性的类型检查是严格的,要求完全匹配。 另外,在Multiplexer.ts中,我们传递自定义事件对象给事件处理函数,这些处理函数期望的是标准事件类型。因此,自定义事件类必须完全实现标准事件接口。 参考引用[1]中提到了类型声明的写法,我们可以借鉴如何声明事件处理函数。引用[4]展示了WebSocket事件处理函数的使用,其中事件参数都是标准事件类型(Event, MessageEvent, CloseEvent)。因此,我们的自定义事件类必须与这些标准事件类型兼容。 代码示例修正: 以CloseEventClass.ts为例: 修改前(可能导致错误的版本): ```typescript import { CloseEvent } from './Event'; export class CloseEvent2 implements CloseEvent { public static NONE = 0; // 这里类型被推断为number // 其他属性和方法 // ... } ``` 修改后: ```typescript import { CloseEvent } from './Event'; export class CloseEvent2 implements CloseEvent { public static readonly NONE: 0 = 0; // 明确指定为0类型 // 确保其他属性和方法也符合CloseEvent接口 public readonly code: number; public readonly reason: string; public readonly wasClean: boolean; constructor(code: number, reason?: string) { this.code = code; this.reason = reason || ''; this.wasClean = (code >= 1000 && code < 1015 && code !== 1005 && code !== 1006); } // 其他需要实现的属性和方法... } ``` 注意:我们还需要根据标准接口`CloseEvent`实现其他必要的属性和方法。这里仅以`NONE`为例。 同理,修改其他自定义事件类。 如果修改后仍然存在其他属性不兼容的错误,请根据错误提示逐一检查并修正。 最后,重新编译项目,观察错误是否消除。 如果问题仍然存在,请检查标准事件接口(CloseEvent, ErrorEvent, MessageEvent)的定义,确保自定义事件类完全实现了这些接口。 由于引用[3]中提到,遇到类型声明问题可以参考lodash的声明,但这里我们处理的是DOM事件,所以更应该参考TypeScript内置的lib.dom.d.ts中的定义。 总结: 解决此类类型不兼容问题的关键是确保自定义类或对象完全符合目标接口的类型要求,特别是对于字面量类型的属性,必须精确匹配。</think>### TypeScript TS2420 和 TS2345 错误解决方案 #### 问题分析 错误的核心在于自定义事件类(如 `CloseEvent2`)与标准 `CloseEvent` 接口的类型冲突,具体表现为 `NONE` 属性的类型不兼容: - 标准接口要求 `NONE` 为字面量类型 `0` - 自定义类实现为 `number` 类型 ```typescript // 标准接口定义 (lib.dom.d.ts) interface CloseEvent { readonly NONE: 0; // 其他属性... } // 自定义类实现 class CloseEvent2 implements CloseEvent { static NONE = 0; // 被推断为 number 类型 // 错误:Type 'number' is not assignable to type '0' } ``` #### 解决方案 ##### 1. 精确匹配字面量类型 **修改自定义事件类**,明确声明静态属性为字面量 `0`: ```typescript class CloseEvent2 implements CloseEvent { static readonly NONE: 0 = 0; // ✅ 精确匹配字面量类型 // 其他属性和方法... } ``` ##### 2. 使用类型断言(临时方案) 在需要传递自定义事件的场景,使用类型断言: ```typescript // Multiplexer.ts 中的示例 this.dispatchEvent(new CloseEvent2(code, reason) as CloseEvent); // ✅ ``` ##### 3. 实现完整接口 确保自定义类完整实现接口要求的所有属性和方法: ```typescript class CloseEvent2 implements CloseEvent { static readonly NONE: 0 = 0; readonly code: number; readonly reason: string; readonly wasClean: boolean; constructor(code: number, reason: string) { this.code = code; this.reason = reason; this.wasClean = (code >= 1000 && code < 1015); } // 实现其他必需方法 initCloseEvent(...) { /* ... */ } } ``` ##### 4. 使用类型适配层 创建适配器函数处理类型转换: ```typescript function createCloseEvent(code: number, reason: string): CloseEvent { return new CloseEvent2(code, reason) as unknown as CloseEvent; } ``` #### 完整实现示例 ```typescript // CloseEventClass.ts export class CloseEvent2 implements CloseEvent { static readonly NONE: 0 = 0; readonly bubbles = false; readonly cancelable = false; readonly code: number; readonly reason: string; readonly wasClean: boolean; constructor(code: number, reason: string = "") { this.code = code; this.reason = reason; this.wasClean = (code >= 1000 && code < 1015); } // 实现标准方法 initCloseEvent(type: string, canBubble: boolean, cancelable: boolean) { // 具体实现... } } ``` #### 最佳实践建议 1. **接口优先设计**:先定义完整接口再实现类 ```typescript interface CustomCloseEvent extends CloseEvent { customProperty: string; } ``` 2. **使用类型测试**:验证实现是否符合接口 ```typescript const testEvent: CloseEvent = new CloseEvent2(1000); // ✅ 编译时检查 ``` 3. **避免扩展内置类型**:优先使用组合而非继承 ```typescript class SafeCloseEvent { private readonly nativeEvent: CloseEvent; get code() { return this.nativeEvent.code; } } ``` #### 类型系统原理 TypeScript 的结构类型系统通过 **鸭子类型** 进行检查: ```typescript interface A { x: 0 } class B { static x = 0 } // 推断为number // 类型检查过程 const check: A = B; // ❌ 失败 // 因为 typeof B.x === number 不匹配 A.x 的 0 ``` 通过精确声明字面量类型 `0`,我们确保类型结构完全匹配[^1][^3]。 #### 相关问题 1. 如何在 TypeScript 中精确匹配接口的字面量类型属性? 2. TypeScript 的结构类型系统在接口实现中如何工作? 3. 实现 DOM 事件接口时应遵循哪些最佳实践? 4. 如何设计自定义事件系统并保持与原生事件兼容? 5. TypeScript 中的类型断言在什么场景下适用?
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