是否可以在JavaScript中以编程方式模拟按键事件?


当前回答

这是我找到的:

函数createKeyboardEvent(名称,键,altKey, ctrlKey, shiftKey, metaKey,气泡){ var e = new事件(name) E.key = key e.keyCode = e.key.charCodeAt(0) e.which = e.keyCode e.altKey = altKey e.ctrlKey = ctrlKey e.shiftKey = shiftKey e.metaKey = metaKey e.泡泡=泡泡 返回e } Var name = 'keydown' Var键= 'a' var event = createKeyboardEvent(name, key, false, false, false, false, true) 文档。addEventListener(name, () => {}) document.dispatchEvent(事件)

其他回答

我想模拟按Tab键……扩展Trevor的回答,我们可以看到像“tab”这样的特殊键确实会被按下,但我们看不到按“tab”会产生的实际结果……

尝试与调度这些事件的'activeElement'以及全局文档对象都-代码添加下面;

代码片段如下:

var element = document.getElementById("firstInput"); document.addEventListener("keydown", function(event) { console.log('we got key:', event.key, ' keyCode:', event.keyCode, ' charCode:', event.charCode); /* enter is pressed */ if (event.keyCode == 13) { console.log('enter pressed:', event); theKey = 'Tab'; attributes = { bubbles: true, key: theKey, keyCode: 9, charCode: 0, }; setTimeout(function() { /* event.keyCode = 13; event.target.value += 'b'; */ var e = new window.KeyboardEvent('focus', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('keydown', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('beforeinput', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('keypress', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('input', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('change', attributes); document.activeElement.dispatchEvent(e); e = new window.KeyboardEvent('keyup', attributes); document.activeElement.dispatchEvent(e); }, 4); setTimeout(function() { var e = new window.KeyboardEvent('focus', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('keydown', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('beforeinput', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('keypress', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('input', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('change', attributes); document.dispatchEvent(e); e = new window.KeyboardEvent('keyup', attributes); document.dispatchEvent(e); }, 100); } else if (event.keyCode != 0) { console.log('we got a non-enter press...: :', event.key, ' keyCode:', event.keyCode, ' charCode:', event.charCode); } }); <h2>convert each enter to a tab in JavaScript... check console for output</h2> <h3>we dispatchEvents on the activeElement... and the global element as well</h3> <input type='text' id='firstInput' /> <input type='text' id='secondInput' /> <button type="button" onclick="document.getElementById('demo').innerHTML = Date()"> Click me to display Date and Time.</button> <p id="demo"></p>

如果你可以使用jQuery 1.3.1:

函数simulateKeyPress(字符){ jQuery.event.trigger ({ 类型:键盘按键, 其中:character.charCodeAt (0) }); } $(函数(){ 美元(的身体).keypress(函数(e) { 警报(e.which); }); simulateKeyPress(“e”); }); < script src = " https://cdnjs.cloudflare.com/ajax/libs/jquery/1.3.1/jquery.min.js " > > < /脚本

这就是我在chrome中使用js/typescript所做的尝试。多亏了 这是灵感的答案。

var x = document.querySelector('input');

var keyboardEvent = new KeyboardEvent("keypress", { bubbles: true });
// you can try charCode or keyCode but they are deprecated
Object.defineProperty(keyboardEvent, "key", {
  get() {
    return "Enter";
  },
});
x.dispatchEvent(keyboardEvent);

{ // example document.querySelector('input').addEventListener("keypress", e => console.log("keypress", e.key)) // unfortunatelly doesn't trigger submit document.querySelector('form').addEventListener("submit", e => { e.preventDefault(); console.log("submit") }) } var x = document.querySelector('input'); var keyboardEvent = new KeyboardEvent("keypress", { bubbles: true }); // you can try charCode or keyCode but they are deprecated Object.defineProperty(keyboardEvent, "key", { get() { return "Enter"; }, }); x.dispatchEvent(keyboardEvent); <form> <input> </form>

下面是一个在Chrome和Chromium上工作的解决方案(只测试了这些平台)。似乎Chrome有一些错误或自己的方法来处理关键代码,所以这个属性必须单独添加到KeyboardEvent。

函数simulateKeydown (keycode, istrl,isAlt,isShift){ var e = new KeyboardEvent("keydown",{冒泡泡:true, cancelable:true, char:String.fromCharCode(keycode), key:String.fromCharCode(keycode), shiftKey:isShift, ctrlKey:isCtrl, altKey:isAlt}); Object.defineProperty(e, 'keyCode', {get: function(){返回this.keyCodeVal;}}); e.keyCodeVal = keycode; document.dispatchEvent (e); } simulateKeydown(39, false, false, false);

你可以在EventTarget(元素,窗口,文档等)上分派键盘事件,如下所示:

element.dispatchEvent(new KeyboardEvent('keydown', {'key': 'a'}));

但是,dispatchEvent可能不会更新输入字段值,也可能不会触发常规键盘按下的行为,这可能是因为Event的原因。itrusted property,我不知道是否有办法绕过

但是你也可以通过设置输入值来改变输入。

element.value += "a";

例子:

let element = document.querySelector('input'); 元素。Onkeydown = e =>警报(e.key); changeValButton。Onclick =() =>元素。Value += "a"; dispatchButton。Onclick = () => { 元素。dispatchEvent(new KeyboardEvent('keydown', {'key': 'a'})); } <输入/ > <button id="dispatchButton">按下分派事件</button> <button id="changeValButton">按下按钮更改值</button> . </button id="changeValButton">


您可以根据需要向事件添加更多属性,如本答案所示。看一下KeyboardEvent文档

element.dispatchEvent(new KeyboardEvent("keydown", {
    key: "e",
    keyCode: 69, // example values.
    code: "KeyE", // put everything you need in this object.
    which: 69,
    shiftKey: false, // you don't need to include values
    ctrlKey: false,  // if you aren't going to use them.
    metaKey: false   // these are here for example's sake.
}));

    

此外,由于keypress已弃用,您可以使用keydown + keyup,例如:

element.dispatchEvent(new KeyboardEvent('keydown', {'key':'Shift'} ));
element.dispatchEvent(new KeyboardEvent( 'keyup' , {'key':'Shift'} ));

对于使用ReactJS的页面,这是一个尝试模拟键盘行为的线程