export class DrawerControl { constructor(selector, robotSelector, mapSelector, mapPath) { this.me = document.querySelector(selector) this.ctx = null if (this.me.getContext) { this.ctx = this.me.getContext('2d') this.resize() } else { throw new Error('canvas context:2d is not available!') } this.me.onmousedown = this.onMouseDown this.me.onmouseup = this.onMouseUp this.me.onmousemove = this.onMouseMove this.me.onmousewheel = this.onMouseWheel this.me.oncontextmenu = this.onMouseRightClick这样的一段canvas代码怎么和this.me.contex一样添加双击事件
时间: 2024-04-17 15:24:57 浏览: 25
要为canvas元素添加双击事件,可以使用addEventListener方法将双击事件绑定到canvas元素上。具体的代码如下:
```javascript
this.me.addEventListener('dblclick', this.onDoubleClick)
```
在构造函数中添加上述代码即可。这样,当canvas元素被双击时,会触发`onDoubleClick`方法。你可以根据需要定义`onDoubleClick`方法来处理双击事件。
相关问题
class Player { constructor(x, y, radius, color, vector) { this.x = x; this.y = y; this.radius = radius; this.color = color; this.vector = vector; this.life = 3;//玩家生命值 } draw(ctx) { ctx.save(); ctx.beginPath(); ctx.fillStyle = this.color; ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false); ctx.fill(); ctx.closePath(); ctx.restore(); } resize(x, y) { this.x = x; this.y = y; } } class Enemy { constructor(x, y, radius, color, vector) { this.x = x; this.y = y; this.radius = radius; this.color = color; this.vector = vector; } draw(ctx) { ctx.save(); ctx.beginPath(); ctx.fillStyle = this.color; ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false); ctx.fill(); ctx.closePath(); ctx.restore(); } update() { this.x += this.vector.x; this.y += this.vector.y; } } 要为玩家添加生命值。判断敌人与玩家是否撞击,是则玩家的生命值减1当玩家生命值减到0时,游戏结束。
可以在 `Player` 类中添加一个 `life` 属性来表示玩家的生命值,并将其初始化为 3。然后在 `Enemy` 类中添加一个 `checkCollision()` 方法来检测敌人与玩家是否撞击,如果撞击,则将玩家的生命值减 1。在 `Player` 类中添加一个 `checkGameOver()` 方法来检测玩家生命值是否减为 0,如果减为 0,则游戏结束。
下面是修改后的代码:
```
class Player {
constructor(x, y, radius, color, vector) {
this.x = x;
this.y = y;
this.radius = radius;
this.color = color;
this.vector = vector;
this.life = 3; // 玩家生命值
}
draw(ctx) {
ctx.save();
ctx.beginPath();
ctx.fillStyle = this.color;
ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false);
ctx.fill();
ctx.closePath();
ctx.restore();
}
resize(x, y) {
this.x = x;
this.y = y;
}
checkGameOver() {
if (this.life === 0) {
// 游戏结束
console.log('Game over');
}
}
}
class Enemy {
constructor(x, y, radius, color, vector) {
this.x = x;
this.y = y;
this.radius = radius;
this.color = color;
this.vector = vector;
}
draw(ctx) {
ctx.save();
ctx.beginPath();
ctx.fillStyle = this.color;
ctx.arc(this.x, this.y, this.radius, 0, Math.PI * 2, false);
ctx.fill();
ctx.closePath();
ctx.restore();
}
update() {
this.x += this.vector.x;
this.y += this.vector.y;
}
checkCollision(player) {
const distance = Math.sqrt((player.x - this.x) ** 2 + (player.y - this.y) ** 2);
if (distance < player.radius + this.radius) {
// 玩家与敌人撞击,玩家生命值减1
player.life--;
console.log('Life:', player.life);
}
}
}
```
// 下载器类 class Downloader { constructor(data, options) { this.data = data; this.options = options; this.item = null; this.onStart = null; this.onProgress = null; this.onCompleted = null; this.data.progress = 0; // 新增 progress 属性 this.data.status='pause';//true 表示 进度没有结束,继续下载 this.data.timeid=0; } start() { const win = BrowserWindow.getFocusedWindow(); this.options.onStarted = (item) => { this.item = item; this.data.status='process';//true 表示 进度没有结束,继续下载 this.onStart(); }; this.options.onTotalProgress=(progress)=>{ this.data.progress = progress.percent * 100; // 更新 progress 属性 this.onTotalProgress(progress); } this.options.onCompleted = () => { this.onCompleted(); }; download(win, this.data.dowloadLink, this.options); } pause() { if (this.item) { this.item.pause(); } } resume() { if (this.item) { this.item.resume(); } } cancel() { if (this.item) { this.item.cancel(); } } } 这是我说的类,里面有异步方法,怎么实现
你可以在异步方法执行完毕后,通过 Promise 或回调函数的方式通知外部代码。例如,在 onCompleted 回调函数中设置一个 Promise,然后在外部代码中等待这个 Promise 执行完毕,再执行下一步操作。类似下面这样:
```
class Downloader {
constructor(data, options) {
this.data = data;
this.options = options;
this.item = null;
this.onStart = null;
this.onProgress = null;
this.onCompleted = null;
this.data.progress = 0;
this.data.status = 'pause';
this.data.timeid = 0;
}
start() {
const win = BrowserWindow.getFocusedWindow();
this.options.onStarted = (item) => {
this.item = item;
this.data.status = 'process';
this.onStart();
};
this.options.onTotalProgress = (progress) => {
this.data.progress = progress.percent * 100;
this.onTotalProgress(progress);
};
this.options.onCompleted = () => {
this.onCompletedPromise.resolve(); // 执行 Promise
};
this.onCompletedPromise = {}; // 保存 Promise 对象
this.onCompletedPromise.promise = new Promise((resolve, reject) => {
this.onCompletedPromise.resolve = resolve;
this.onCompletedPromise.reject = reject;
});
download(win, this.data.dowloadLink, this.options);
}
async pause() {
if (this.item) {
await this.onCompletedPromise; // 等待 Promise 执行完毕
this.item.pause();
}
}
async resume() {
if (this.item) {
await this.onCompletedPromise; // 等待 Promise 执行完毕
this.item.resume();
}
}
async cancel() {
if (this.item) {
await this.onCompletedPromise; // 等待 Promise 执行完毕
this.item.cancel();
}
}
}
```
这样就能保证异步方法执行完毕后再执行外部代码了。