按键保持延迟。 Javascript

Question

因此操作系统在您按住某个键时会有延迟。它将执行命令一次，延迟，然后重复。我试图通过根据密钥具有 "keydown" 和 "Keyup." 的时间将变量设置为 true 或 false 来绕过此问题，但我不确定为什么它不起作用。我不确定我是否忘记了什么，但如果有人能解释为什么我的代码仍然没有解决问题。

变量

var keyPressed = {Kleft: 37, Kright: 39, Kup: 38,  Kdown: 40, Kspace: 32};
    key = {K37: false, K39: false, K38: false, K40: false, K32: false};

检测按键被按下

//to detect multiple keys being pressed 
    $(document).keydown(function(e) {
        if(keyPressed.Kleft)    //left arrow
            {
                console.log('test');
                key.K37 = true;
                airplane.performAction();
            }
        if(keyPressed.Kright) //right arrow
            {
                key.K37 = true;
                // airplane.performAction();
            }
        if(keyPressed.Kup)  //up arrow
            {
                key.K37 = true;
                // airplane.performAction();
            }
        if(keyPressed.Kdown) //down arrow
            {
                key.K37 = true;
                // airplane.performAction();
            }
        if(keyPressed.Kspace)   //space key
            {
                key.K37 = true;
                bullet = new Bullet({x: airplane.position.x+32, y: airplane.position.y-12}, bullets_total++); //create a new bullet
                bullets.push(bullet); //store the bullet in the bullets array
            }
    }).keyup(function(e) {
        key.K37 = false; //testing just one key for now
        console.log('ehhlo');
        // console.log(key['K'+toString(e)]);
        // key['K'+toString(e)] = false;
    });

Keypress 上执行的函数

function MyAirplane()
{
    this.performAction = function(action)
    {
        if(key.K37 === true){
            console.log('left');
            this.position.x -= 10;
        }
        if(key.K37 == true){
            this.position.x += 10;
        }
        if(key.K37 == true){
            this.position.y -= 10;
        }
        if(key.K37 == true){
            this.position.y += 10;
        }
    }
}

Answer 1

一个想法，尽量不要自动调用performAction。

//to detect multiple keys being pressed 
$(document).keydown(function(e) {
    if(keyPressed.Kleft)    //left arrow
        {
            key.K37 = true;
        }
    if(keyPressed.Kright) //right arrow
        {
            key.K37 = true;
        }
    if(keyPressed.Kup)  //up arrow
        {
            key.K37 = true;
        }
    if(keyPressed.Kdown) //down arrow
        {
            key.K37 = true;
        }
    if(keyPressed.Kspace)   //space key
        {
            key.K37 = true;
            bullet = new Bullet({x: airplane.position.x+32, y: airplane.position.y-12}, bullets_total++); //create a new bullet
            bullets.push(bullet); //store the bullet in the bullets array
        }
}).keyup(function(e) {
    key.K37 = false; //testing just one key for now
    console.log('ehhlo');
    // console.log(key['K'+toString(e)]);
    // key['K'+toString(e)] = false;
});

并创建事件计时器：

function MyAirplane()
{
    this.performAction = function(action)
    {
        if(key.K37 === true){
            console.log('left');
            this.position.x -= 10;
        }
        if(key.K37 == true){
            this.position.x += 10;
        }
        if(key.K37 == true){
            this.position.y -= 10;
        }
        if(key.K37 == true){
            this.position.y += 10;
        }
    }
    // 60 frames per second event checker.
    var eventLoop = setInterval(this.performAction.bind(this), 1000 / 60);
}

按键保持延迟。 Javascript

keydown hold delay. Javascript

javascript

delay

keydown