我试图开发一个JavaScript游戏引擎,我遇到了这个问题:

当我按空格键时,角色会跳跃。 当我按下→角色向右移动。

问题是,当我按右键,然后按空格键时,角色会跳跃,然后停止移动。

我使用keydown函数来按下键。如何检查是否同时按下了多个键?


当前回答

我喜欢使用这个片段,它对于编写游戏输入脚本非常有用

var keyMap = [];

window.addEventListener('keydown', (e)=>{
    if(!keyMap.includes(e.keyCode)){
        keyMap.push(e.keyCode);
    }
})

window.addEventListener('keyup', (e)=>{
    if(keyMap.includes(e.keyCode)){
        keyMap.splice(keyMap.indexOf(e.keyCode), 1);
    }
})

function key(x){
    return (keyMap.includes(x));
}

function checkGameKeys(){
    if(key(32)){
        // Space Key
    }
    if(key(37)){
        // Left Arrow Key
    }
    if(key(39)){
        // Right Arrow Key
    }
    if(key(38)){
        // Up Arrow Key
    }
    if(key(40)){
        // Down Arrow Key
    }
    if(key(65)){
        // A Key
    }
    if(key(68)){
        // D Key
    }
    if(key(87)){
        // W Key
    }
    if(key(83)){
        // S Key
    }
}

其他回答

    $(document).ready(function () {
        // using ascii 17 for ctrl, 18 for alt and 83 for "S"
        // ctr+alt+S
        var map = { 17: false, 18: false, 83: false };
        $(document).keyup(function (e) {
            if (e.keyCode in map) {
                map[e.keyCode] = true;
                if (map[17] && map[18] && map[83]) {
                    // Write your own code here, what  you want to do
                    map[17] = false;
                    map[18] = false;
                    map[83] = false;
                }
            }
            else {
                // if u press any other key apart from that "map" will reset.
                map[17] = false;
                map[18] = false;
                map[83] = false;
            }
        });

    });

这是布雷登斯答案的一个实现。

Var键= {} handleKeyPress(evt) { let {keyCode, type} = evt ||事件;//处理IE let isKeyDown = (type == 'keydown'); keys[keyCode] = isKeyDown; // test: enter键被按下,shift键没有被按下 if(isKeyDown && keys[13] && !keys[16]){ Console.log('用户按下enter没有shift') } }; 窗口。addEventListener(“弹起”,handleKeyPress); 窗口。addEventListener(“keydown”,handleKeyPress);

只是让某些东西更稳定:

var keys = [];
$(document).keydown(function (e) { 
    if(e.which == 32 || e.which == 70){
    keys.push(e.which);
    if(keys.length == 2 && keys.indexOf(32) != -1 && keys.indexOf(70) != -1){
        
        
        
        alert("it WORKS !!"); //MAKE SOMETHING HERE---------------->
        
        
        
        keys.length = 0;
    }else if((keys.indexOf(32) == -1 && keys.indexOf(70) != -1) || (keys.indexOf(32) != -1 && keys.indexOf(70) == -1) && (keys.indexOf(32) > 1 || keys.indexOf(70) > 1)){
    }else{
        keys.length = 0;
    }
}else{
    keys.length = 0;
}
});
Easiest, and most Effective Method

//check key press
    function loop(){
        //>>key<< can be any string representing a letter eg: "a", "b", "ctrl",
        if(map[*key*]==true){
         //do something
        }
        //multiple keys
        if(map["x"]==true&&map["ctrl"]==true){
         console.log("x, and ctrl are being held down together")
        }
    }

//>>>variable which will hold all key information<<
    var map={}

//Key Event Listeners
    window.addEventListener("keydown", btnd, true);
    window.addEventListener("keyup", btnu, true);

    //Handle button down
      function btnd(e) {
      map[e.key] = true;
      }

    //Handle Button up
      function btnu(e) {
      map[e.key] = false;
      }

//>>>If you want to see the state of every Key on the Keybaord<<<
    setInterval(() => {
                for (var x in map) {
                    log += "|" + x + "=" + map[x];
                }
                console.log(log);
                log = "";
            }, 300);

我使用case, if和bool。我有一个项目,这对我很有效


window.addEventListener("keydown", onKeyDown, false);
window.addEventListener("keyup", onKeyUp, false);

function onKeyDown(event) {
  var keyCode = event.keyCode;
  switch (keyCode) {
    case 68: //D
      keyd = true;
      break;
    case 32: //spaaaaaaaaaaaaaaace
      keyspace = true;
      break;
    case 65: //A
      keya = true;
      break;
    case 37:
      keya = true;
      break;
    case 38:
      keyspace = true;
      break;
    case 39:
      keyd = true;
      break;
  }
}

function onKeyUp(event) {
  var keyCode = event.keyCode;

  switch (keyCode) {
    case 68: //dddddd
      keyd = false;
      break;
    case 32: //spaaaaaaaaaaaaaaaaaaaaaace
      keyspace = false;
      break;
    case 65: //aaaaa
      keya = false;
      break;
    case 37:
      keya = false;
      break;
    case 38:
      keyspace = false;
      break;
    case 39:
      keyd = false;
      break;
  }
}