How to take keyboard input in JavaScript?

前端未结

关注

 5  1999

I want to take keyboard input in JavaScript, where arrow keys, when pressed, will result in the change in shape of a particular shape. How do I take the input of any of the

相关标签:

5条回答

梦如初夏

2020-12-02 09:18
Use JQuery keydown event.
```
$(document).keypress(function(){
    if(event.which == 70){  //f
        console.log("You have payed respect");
    }
});
```
In JS; keyboard keys are identified by Javascript keycodes
0 讨论(0)
发布评论:

提交评论
- 加载中...

孤城傲影

2020-12-02 09:22

You should register an event handler on the window or any element that you want to observe keystrokes on, and use the standard key values instead of keyCode. This modified code from MDN will respond to keydown when the left, right, up, or down arrow keys are pressed:

window.addEventListener("keydown", function (event) {
  if (event.defaultPrevented) {
    return; // Do nothing if the event was already processed
  }

  switch (event.key) {
    case "ArrowDown":
      // code for "down arrow" key press.
      break;
    case "ArrowUp":
      // code for "up arrow" key press.
      break;
    case "ArrowLeft":
      // code for "left arrow" key press.
      break;
    case "ArrowRight":
      // code for "right arrow" key press.
      break;
    default:
      return; // Quit when this doesn't handle the key event.
  }

  // Cancel the default action to avoid it being handled twice
  event.preventDefault();
}, true);
// the last option dispatches the event to the listener first,
// then dispatches event to window

0 讨论(0)

鱼传尺愫

2020-12-02 09:29

Since event.keyCode is deprecated, I found the event.key useful in javascript. Below is an example for getting the names of the keyboard keys pressed (using an input element). They are given as a KeyboardEvent key text property:

function setMyKeyDownListener() {
    window.addEventListener(
      "keydown",
      function(event) {MyFunction(event.key)}
    )
}

function MyFunction (the_Key) {
    alert("Key pressed is: "+the_Key);
}

html { font-size: 4vw; background-color: green; color: white; padding: 1em; }

<body onload="setMyKeyDownListener()">
    <div>
        <input id="MyInputId">
    </div>
</body>
</html>

0 讨论(0)

小蘑菇

2020-12-02 09:30
You can do this by registering an event handler on the document or any element you want to observe keystrokes on and examine the key related properties of the event object.

Example that works in FF and Webkit-based browsers:
```
document.addEventListener('keydown', function(event) {
    if(event.keyCode == 37) {
        alert('Left was pressed');
    }
    else if(event.keyCode == 39) {
        alert('Right was pressed');
    }
});
```
DEMO
0 讨论(0)
发布评论:

提交评论
- 加载中...
悲哀的现实

2020-12-02 09:39
If you are doing this in a browser, you can capture keyboard events.
- keydown
- keypress
- keyup
Can all be listened to on HTML nodes in most browsers.

Webkit also supports...
- textInput
See for more details .. http://unixpapa.com/js/key.html
0 讨论(0)
发布评论:

提交评论
- 加载中...