HTML 输入文件选择事件在选择同一文件时不会触发 [英] HTML input file selection event not firing upon selecting the same file

问题描述

是否有机会检测用户为 file 元素类型的 HTML input 所做的每个文件选择?

Is there any chance to detect every file selection the user made for an HTML input of type file element?

这之前被问过很多次，但如果用户再次选择相同的文件，通常建议的 onchange 事件不会触发.

This was asked many times before, but the usually proposed onchange event doesn't fire if the user select the same file again.

推荐答案

在每个 onclick 事件上将 input 的值设置为 null.即使选择了相同的路径，这也会重置 input 的值并触发 onchange 事件.

Set the value of the input to null on each onclick event. This will reset the input's value and trigger the onchange event even if the same path is selected.

var input = document.getElementsByTagName('input')[0];

input.onclick = function () {
  this.value = null;
};
  
input.onchange = function () {
  console.log(this.value);
};

<input type="file" value="C:fakepath">

注意:如果您的文件以C:fakepath"为前缀是正常的.这是一项安全功能，可防止 JavaScript 知道文件的绝对路径.浏览器内部仍然知道它.

Note: It's normal if your file is prefixed with 'C:fakepath'. That's a security feature preventing JavaScript from knowing the file's absolute path. The browser still knows it internally.

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