是否可以在JavaScript中以编程方式模拟按键事件?
当前回答
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>
其他回答
只需使用CustomEvent
Node.prototype.fire=function(type,options){
var event=new CustomEvent(type);
for(var p in options){
event[p]=options[p];
}
this.dispatchEvent(event);
}
4 ex想模拟ctrl+z
window.addEventListener("keyup",function(ev){
if(ev.ctrlKey && ev.keyCode === 90) console.log(ev); // or do smth
})
document.fire("keyup",{ctrlKey:true,keyCode:90,bubbles:true})
在alex2k8的基础上,这里有一个修订版,可以在jQuery支持的所有浏览器中工作(问题是缺少jQuery.event的参数。触发器,在使用内部函数时很容易忘记它)。
// jQuery plugin. Called on a jQuery object, not directly.
jQuery.fn.simulateKeyPress = function (character) {
// Internally calls jQuery.event.trigger with arguments (Event, data, elem).
// That last argument, 'elem', is very important!
jQuery(this).trigger({ type: 'keypress', which: character.charCodeAt(0) });
};
jQuery(function ($) {
// Bind event handler
$('body').keypress(function (e) {
alert(String.fromCharCode(e.which));
console.log(e);
});
// Simulate the key press
$('body').simulateKeyPress('x');
});
您甚至可以更进一步,让它不仅模拟事件,而且实际插入字符(如果它是一个输入元素),但是在尝试这样做时,有许多跨浏览器的问题。最好使用更精致的插件,如SendKeys。
基于@aljgom的回答:
这对我来说很有效。而不是像aljgom建议的那样将事件分派给元素,而是将它分派给文档。
document.dispatchEvent(new KeyboardEvent("keydown", { key: "c" }));
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>
让它工作的关键部分是认识到charCode, keyCode和这些都是不推荐的方法。因此,如果处理按键事件的代码使用这三个中的任何一个,那么它将收到一个伪答案(例如,默认值为0)。
只要使用非弃用的方法(如key)访问按键事件,就应该没问题。
为了完成,我添加了触发事件的基本Javascript代码:
const rightArrowKey = 39 const event = new KeyboardEvent('keydown',{'key':rightArrowKey}) document.dispatchEvent(事件)