所以我想在javascript游戏上实现简单的触控。我从搜索中得到以下答案：
Snake Game with Controller Buttons for Mobile Use **UPDATED**
但是我试图将此jquery更改为javascript，以便它可以与我的游戏一起使用
jQuery的：
$(document).on('click', '.button-pad > button', function(e) {
if ($(this).hasClass('left-btn')) {
e = 37;
}
使用Javascript：
var contoller = document.getElementById("button-pad").on('click',
'.button-pad > button', function(e) {
if ('.button-pad > button'(this).hasClass('btn-left')) {
e = 37;
}
我以为我把它分类了但它根本不起作用
Codepen在这里：
你现有的代码有一些问题，但它足够接近我可以翻译它。但是，您当前的代码似乎想要将传递给click处理程序（e）的事件参数重新分配给37。这毫无意义。很可能你只想要另一个变量设置为37，这就是我在下面所做的：
spaceInvader(window, document.getElementById('space-invader'));
window.focus();
let game = null;
let ship = null;
function spaceInvader (window, canvas) {
canvas.focus();
var context = canvas.getContext('2d');
/* GAME */
function Game () {
this.message = '';
this.rebel = [];
this.republic = [];
this.other = [];
this.size = {x: canvas.width, y: canvas.height};
this.wave = 0;
this.refresh = function () {
this.update();
this.draw();
requestAnimationFrame(this.refresh);
}.bind(this);
this.init();
}
Game.MESSAGE_DURATION = 1500;
Game.prototype.init = function () {
this.ship = new Ship(this);
this.addRebel(this.ship);
this.refresh();
};
Game.prototype.update = function () {
this.handleCollisions();
this.computeElements();
this.elements.forEach(Element.update);
if (!this.rebel.length) {
this.showText('Gatwick closed', true);
return;
}
if (!this.republic.length) this.createWave();
};
Game.prototype.draw = function () {
context.clearRect(0, 0, this.size.x, this.size.y);
this.elements.forEach(Element.draw);
Alien.drawLife(this.republic);
if (this.message) {
context.save();
context.font = '30px Arial';
context.textAlign='center';
context.fillStyle = '#FFFFFF';
context.fillText(this.message, canvas.width / 2, canvas.height / 2);
context.restore();
}
};
Game.prototype.computeElements = function () {
this.elements = this.other.concat(this.republic, this.rebel);
};
Game.prototype.addRebel = function (element) {
this.rebel.push(element);
};
Game.prototype.addRepublic = function (element) {
this.republic.push(element);
};
Game.prototype.addOther = function (element) {
this.other.push(element);
};
Game.prototype.handleCollisions = function () {
this.rebel.forEach(function(elementA) {
this.republic.forEach(function (elementB) {
if (!Element.colliding(elementA, elementB)) return;
elementA.life--;
elementB.life--;
var sizeA = elementA.size.x * elementA.size.y;
var sizeB = elementB.size.x * elementB.size.y;
this.addOther(new Explosion(this, sizeA > sizeB ? elementA.pos : elementB.pos));
}, this);
}, this);
this.republic = this.republic.filter(Element.isAlive);
this.rebel = this.rebel.filter(Element.isAlive);
this.other = this.other.filter(Element.isAlive);
this.republic = this.republic.filter(this.elementInGame, this);
this.rebel = this.rebel.filter(this.elementInGame, this);
};
Game.prototype.elementInGame = function (element) {
return !(element instanceof Bullet) || (
element.pos.x + element.halfWidth > 0 &&
element.pos.x - element.halfWidth < this.size.x &&
element.pos.y + element.halfHeight > 0 &&
element.pos.y - element.halfHeight < this.size.x
);
};
Game.prototype.createWave = function () {
this.ship.life = Ship.MAX_LIFE;
this.ship.fireRate = Math.max(50, Ship.FIRE_RATE - 50 * this.wave);
this.wave++;
this.showText('Wave: ' + this.wave);
var waveSpeed = Math.ceil(this.wave / 2);
var waveProb = (999 - this.wave * 2) / 1000;
var margin = {x: Alien.SIZE.x + 10, y: Alien.SIZE.y + 10};
for (var i = 0; i < 2; i++) {
var x = margin.x + (i % 8) * margin.x;
var y = -200 + (i % 3) * margin.y;
this.addRepublic(new Alien(this, {x: x, y: y}, waveSpeed, waveProb));
}
};
Game.prototype.showText = function (message, final) {
this.message = message;
if (!final) setTimeout(this.showText.bind(this, '', true), Game.MESSAGE_DURATION);
};
/* GENERIC ELEMENT */
function Element (game, pos, size) {
this.game = game;
this.pos = pos;
this.size = size;
this.halfWidth = Math.floor(this.size.x / 2);
this.halfHeight = Math.floor(this.size.y / 2);
}
Element.update = function (element) {
element.update();
};
Element.draw = function (element) {
element.draw();
};
Element.isAlive = function (element) {
return element.life > 0;
};
Element.colliding = function (elementA, elementB) {
return !(
elementA === elementB ||
elementA.pos.x + elementA.halfWidth < elementB.pos.x - elementB.halfWidth ||
elementA.pos.y + elementA.halfHeight < elementB.pos.y - elementB.halfHeight ||
elementA.pos.x - elementA.halfWidth > elementB.pos.x + elementB.halfWidth ||
elementA.pos.y - elementA.halfHeight > elementB.pos.y + elementB.halfHeight
);
};
/* SHIP */
function Ship(game) {
var pos = {
x: Math.floor(game.size.x / 2) - Math.floor(Ship.SIZE.x / 2),
y: game.size.y - Math.floor(Ship.SIZE.y / 2)
};
Element.call(this, game, pos, Ship.SIZE);
this.kb = new KeyBoard();
this.speed = Ship.SPEED;
this.allowShooting = true;
this.life = Ship.MAX_LIFE;
this.fireRate = Ship.FIRE_RATE;
}
Ship.SIZE = {x: 67, y: 100};
Ship.SPEED = 8;
Ship.MAX_LIFE = 5;
Ship.FIRE_RATE = 200;
Ship.prototype.update = function () {
if (this.kb.isDown(KeyBoard.KEYS.LEFT) && this.pos.x - this.halfWidth > 0) {
this.pos.x -= this.speed;
} else if (this.kb.isDown(KeyBoard.KEYS.RIGHT) && this.pos.x + this.halfWidth < this.game.size.x) {
this.pos.x += this.speed;
}
if (this.allowShooting && this.kb.isDown(KeyBoard.KEYS.SPACE)) {
var bullet = new Bullet(
this.game,
{x: this.pos.x, y: this.pos.y - this.halfHeight },
{ x: 0, y: -Bullet.SPEED },
true
);
this.game.addRebel(bullet);
this.toogleShooting();
}
};
Ship.prototype.draw = function () {
var img = document.getElementById('ship');
context.save();
context.translate(this.pos.x - this.halfWidth, this.pos.y - this.halfHeight);
context.drawImage(img, 0, 0);
context.restore();
this.drawLife();
};
Ship.prototype.drawLife = function () {
context.save();
context.fillStyle = 'white';
context.fillRect(this.game.size.x -112, 10, 102, 12);
context.fillStyle = 'red';
context.fillRect(this.game.size.x -111, 11, this.life * 100 / Ship.MAX_LIFE, 10);
context.restore();
};
Ship.prototype.toogleShooting = function (final) {
this.allowShooting = !this.allowShooting;
if (!final) setTimeout(this.toogleShooting.bind(this, true), this.fireRate);
};
/* ALIENS */
function Alien(game, pos, speed, shootProb) {
Element.call(this, game, pos, Alien.SIZE);
this.speed = speed;
this.shootProb = shootProb;
this.life = 3;
this.direction = {x: 1, y: 1};
}
Alien.SIZE = {x: 51, y: 60};
Alien.MAX_RANGE = 350;
Alien.CHDIR_PRO = 0.990;
Alien.drawLife = function (array) {
array = array.filter(function (element) {
return element instanceof Alien;
});
context.save();
context.fillStyle = 'white';
context.fillRect(10, 10, 10 * array.length + 2, 12);
array.forEach(function (alien, idx) {
switch (alien.life) {
case 3:
context.fillStyle = 'green';
break;
case 2:
context.fillStyle = 'yellow';
break;
case 1:
context.fillStyle = 'red';
break;
}
context.fillRect(10 * idx + 11, 11, 10, 10);
});
context.restore();
};
Alien.prototype.update = function () {
if (this.pos.x - this.halfWidth <= 0) {
this.direction.x = 1;
} else if (this.pos.x + this.halfWidth >= this.game.size.x) {
this.direction.x = -1;
} else if (Math.random() > Alien.CHDIR_PRO) {
this.direction.x = -this.direction.x;
}
if (this.pos.y - this.halfHeight <= 0) {
this.direction.y = 1;
} else if (this.pos.y + this.halfHeight >= Alien.MAX_RANGE) {
this.direction.y = -1;
} else if (Math.random() > Alien.CHDIR_PRO) {
this.direction.y = -this.direction.y;
}
this.pos.x += this.speed * this.direction.x;
this.pos.y += this.speed * this.direction.y;
if (Math.random() > this.shootProb) {
var bullet = new Bullet(
this.game,
{x: this.pos.x, y: this.pos.y + this.halfHeight },
{ x: Math.random() - 0.5, y: Bullet.SPEED },
false
);
this.game.addRepublic(bullet);
}
};
Alien.prototype.draw = function () {
var img = document.getElementById('fighter');
context.save();
context.translate(this.pos.x + this.halfWidth, this.pos.y + this.halfHeight);
context.rotate(Math.PI);
context.drawImage(img, 0, 0);
context.restore();
};
/* BULLET */
function Bullet(game, pos, direction, isRebel) {
Element.call(this, game, pos, Bullet.SIZE);
this.direction = direction;
this.isRebel = isRebel;
this.life = 1;
try {
var sound = document.getElementById('sound-raygun');
sound.load();
sound.play().then(function () {}, function () {});
}
catch (e) {
// only a sound issue
}
}
Bullet.SIZE = {x: 6, y: 20};
Bullet.SPEED = 3;
Bullet.prototype.update = function () {
this.pos.x += this.direction.x;
this.pos.y += this.direction.y;
};
Bullet.prototype.draw = function () {
context.save();
var img;
if (this.isRebel) {
context.translate(this.pos.x - this.halfWidth, this.pos.y - this.halfHeight);
img = document.getElementById('rebel-bullet');
}
else {
context.translate(this.pos.x + this.halfWidth, this.pos.y + this.halfHeight);
img = document.getElementById('republic-bullet');
context.rotate(Math.PI);
}
context.drawImage(img, 0, 0);
context.restore();
};
/* EXPLOSION */
function Explosion(game, pos) {
Element.call(this, game, pos, Explosion.SIZE);
this.life = 1;
this.date = new Date();
try {
var sound = document.getElementById('sound-explosion');
sound.load();
sound.play().then(function () {}, function () {});
}
catch (e) {
// only a sound issue
}
}
Explosion.SIZE = {x: 115, y: 100};
Explosion.DURATION = 150;
Explosion.prototype.update = function () {
if (new Date() - this.date > Explosion.DURATION) this.life = 0;
};
Explosion.prototype.draw = function () {
var img = document.getElementById('explosion');
context.save();
context.translate(this.pos.x - this.halfWidth, this.pos.y - this.halfHeight);
context.drawImage(img, 0, 0);
context.restore();
};
/* KEYBOARD HANDLING */
function KeyBoard() {
var state = {};
window.addEventListener('keydown', function(e) {
state[e.keyCode] = true;
});
window.addEventListener('keyup', function(e) {
state[e.keyCode] = false;
});
this.isDown = function (key) {
return state[key];
};
}
KeyBoard.KEYS = {
LEFT: 37,
RIGHT: 39,
SPACE: 32
};
window.addEventListener('load', function() {
game = new Game();
});
// Get all the button elements that are children of elements that have
// the .button-pad class and convert the resulting node list into an Array
let elements =
Array.prototype.slice.call(document.querySelectorAll('.button-pad button'));
// Loop over the array
elements.forEach(function(el){
el.textContent = "XXXX";
// Set up a click event handler for the current element being iterated:
el.addEventListener('click', function(e) {
// When the element is clicked, check to see if it uses the left-btn class
if(this.classList.contains('left-btn')) {
// Perform whatever actions you need to:
ship.update();
}
});
});
}<h1>Gatwick invaders</h1>
<p>Press <b>left arrow</b> to go left, <b>right arrow</b> to go right, and <b>space</b> to shoot...</p>
<canvas id="space-invader" width="640" height="500" tabindex="0"></canvas>
<img id="fighter" src="https://raw.githubusercontent.com/MrVIncentRyan/assets/master/drone1.png" />
<img id="ship" src="https://raw.githubusercontent.com/MrVIncentRyan/assets/master/cop1.png" />
<img id="rebel-bullet" src="https://raw.githubusercontent.com/OlivierB-OB/starwars-invader/master/rebelBullet.png" />
<img id="republic-bullet" src="https://raw.githubusercontent.com/OlivierB-OB/starwars-invader/master/republicBullet.png" />
<img id="explosion" src="https://raw.githubusercontent.com/OlivierB-OB/starwars-invader/master/explosion.png" />
<audio id="sound-explosion" src="https://raw.githubusercontent.com/OlivierB-OB/starwars-invader/master/explosion.mp3"></audio>
<audio id="sound-raygun" src="https://raw.githubusercontent.com/OlivierB-OB/starwars-invader/master/raygun.mp3"></audio>
</div>
<div class="button-pad">
<div class="btn-up">
<button type="submit" class="up">
<img src="http://aaronblomberg.com/sites/ez/images/btn-up.png" />
</button>
</div>
<div class="btn-right">
<button type="submit" class="right">
<img src="http://aaronblomberg.com/sites/ez/images/btn-right.png" />
</button>
</div>
<div class="btn-down">
<button type="submit" class="down">
<img src="http://aaronblomberg.com/sites/ez/images/btn-down.png" />
</button>
</div>
<div class="btn-left">
<button type="submit" class="left">
<img src="http://aaronblomberg.com/sites/ez/images/btn-left.png" />
</button>
</div>
</div>A custom solution for emulating keypresses on mobile in both vanilla Javascript as well as jQuery!
// jQuery (edge), for use with ES2015-19
/*
$(document).on("click", ".example-btn", e => { // Click event handler
if($(this).hasClass("example-btn")) { // Verifying that element has class
e = 37
jQuery.event.trigger({type: "keypress", which: character.charCodeAt(e)}) // Simulating keystroke
// The following is simply for debugging, remove if needed
alert("Button validation confirmed!")
console.log("E: ", e)
}
})
*/
// Pure Javascript (ECMA Standard)
document.querySelector(".example-btn").addEventListener("click", function(e) { // Click event handler
if(this.classList.contains("example-btn")) { // Verifying that element has class
e = 37
if(document.createEventObject) {
var eventObj = document.createEventObject();
eventObj.keyCode = e;
document.querySelector(".example-btn").fireEvent("onkeydown", eventObj);
} else if(document.createEvent) {
var eventObj2 = document.createEvent("Events");
eventObj2.initEvent("keydown", true, true);
eventObj2.which = e;
document.querySelector(".example-btn").dispatchEvent(eventObj2);
}
// The following is simply for debugging, remove if needed
alert("Button validation confirmed!");
console.log("E: ", e);
}
});
// ---------------------------------------------------------------------------------------------------
/*
You can not use the "this" statement when referring to an embedded element. In your previous code "this" would refer to ".button-container > .example-btn" which the compiler will interpret as only the parent element, being .button-container (.button-pad in your code) not the child element in which you want. Also there is no such thing as returning a character code and expecting it to automatically know what to do with it. I assume you are doing this to emulate a keystroke on a mobile device and I assure you that this design works although it might be flawed. Give it a try and I hope it does something to at least help if not solve your problem.
*/
// ---------------------------------------------------------------------------------------------------
当事件侦听器附加到元素时，该侦听器对于该元素不是唯一的，而是传播给其子元素。通过在事件侦听器上添加一个以我们想要的元素为目标的参数，在jQuery中启用此功能。这不是vanillaJS中的情况，但是使用e.target我们可以检查事件执行的元素。
可能你看起来像这样。但是，我更喜欢在按钮中添加一个id，以便您可以更轻松地使用它。
document.addEventListener('click', function(e){
if(e.target.tagName === 'BUTTON' && e.target.classList.value.includes('btn-left')){
// execute your code
}
});