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);

谁需要完整的示例代码。左+右补充道

var keyPressed = {};
document.addEventListener('keydown', function(e) {

   keyPressed[e.key + e.location] = true;

    if(keyPressed.Shift1 == true && keyPressed.Control1 == true){
        // Left shift+CONTROL pressed!
        keyPressed = {}; // reset key map
    }
    if(keyPressed.Shift2 == true && keyPressed.Control2 == true){
        // Right shift+CONTROL pressed!
        keyPressed = {};
    }

}, false);

document.addEventListener('keyup', function(e) {
   keyPressed[e.key + e.location] = false;

   keyPressed = {};
}, false);

我会试着在按键时添加一个按键事件处理程序。例句:

window.onkeydown = function() {
    // evaluate key and call respective handler
    window.onkeypress = function() {
       // evaluate key and call respective handler
    }
}

window.onkeyup = function() {
    window.onkeypress = void(0) ;
}

这只是为了说明一个模式;这里我就不详细介绍了(尤其是浏览器特定的level2+事件注册)。

请回复这是否有帮助。

如果有人需要简单的解决方案。

let keys = [];
document.addEventListener("keydown", (e) => {
  keys.push(e.key);
  if (keys.includes("Control") && keys.includes("o")) {
    console.log("open");
  }

  if (keys.includes("Control") && keys.includes("s")) {
    console.log("save");
  }
});

// clear the keys array
document.addEventListener("keyup", () => {
  keys = [];
});

如果你想找到任何按键事件与控制键，你可以这样做

onkeypress = (e) =>{
console.log(e);
if(e.ctrlKey && e.code == "KeyZ"){
    document.write("do somthing")
} }

    $(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;
            }
        });

    });