javascript 在被 javascript 生成的元素激活时不起作用

如何解决javascript 在被 javascript 生成的元素激活时不起作用

我遇到了一个看似简单但令人费解的 javascript 问题。这里我有两个片段； 两者几乎相同，只是后一个代码段的黄色输入框是由 Javascript 生成的。

这两个代码的区别是：

<table><tbody><tr class="newdiv"><td style="background:yellow">enter</td></tr></tbody></table> click the yellow Box!
<br><textarea id="result"></textarea>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
// the script below enables typing 'enter' into textarea by clicking the yellow Box.
$('.newdiv>td').click(function(){
    var range = document.createrange();
    range.selectNodeContents(this);  
    var sel = window.getSelection(); 
    sel.removeAllRanges(); 
    sel.addRange(range);
    insertAtCaret('result',sel);return false;
});
function insertAtCaret(areaId,text) {
  var txtarea = document.getElementById(areaId);
  if (!txtarea) {
    return;
  }
  var scrollPos = txtarea.scrollTop;
  var strPos = 0;
  var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
    "ff" : (document.selection ? "ie" : false));
  if (br == "ie") {
    txtarea.focus();
    var range = document.selection.createrange();
    range.moveStart('character',-txtarea.value.length);
    strPos = range.text.length;
  } else if (br == "ff") {
    strPos = txtarea.selectionStart;
  }
  var front = (txtarea.value).substring(0,strPos);
  var back = (txtarea.value).substring(strPos,txtarea.value.length);
  txtarea.value = front + text + back;
  strPos = strPos + text.length;
  txtarea.scrollTop = scrollPos;
}
</script>

<button onclick="myfunction()">show</button>
<div id="show"></div>
<br><textarea class="txta" id="result"></textarea>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
function myfunction(){
document.getElementById('show').innerHTML = `
<table><tbody><tr class="newdiv"><td style="background:yellow">enter</td></tr></tbody></table> click the yellow Box!
`;
}
// the script below enables typing 'enter' into textarea by clicking the yellow Box.
$('.newdiv>td').click(function(){
    var range = document.createrange();
    range.selectNodeContents(this);  
    var sel = window.getSelection(); 
    sel.removeAllRanges(); 
    sel.addRange(range);
    insertAtCaret('result',txtarea.value.length);
  txtarea.value = front + text + back;
  strPos = strPos + text.length;
  txtarea.scrollTop = scrollPos;
}
</script>

第二个片段的黄色框是由：

function myfunction(){
document.getElementById('show').innerHTML = `
<table><tbody><tr class="newdiv"><td style="background:yellow">enter</td></tr></tbody></table> click the yellow Box!
`;
}

第二个代码段通过javascript函数生成黄色框，输入enter是jquery函数。我的问题是：为什么函数在第一个片段中起作用，而在第二个片段中不起作用，尽管它们的差异（以我的拙见）似乎不会影响函数本身？

解决方法

请使用以下代码更改代码。

来自

$('.newdiv>td').click(function(){
    var range = document.createRange();
    range.selectNodeContents(this);  
    var sel = window.getSelection(); 
    sel.removeAllRanges(); 
    sel.addRange(range);
    insertAtCaret('result',sel);return false;
});

致

$(document).on('click','.newdiv>td',function(){
    var range = document.createRange();
    range.selectNodeContents(this);  
    var sel = window.getSelection(); 
    sel.removeAllRanges(); 
    sel.addRange(range);
    insertAtCaret('result',sel);return false;
});

Reference answer

<button onclick="myfunction()">show</button>
<div id="show"></div>
<br><textarea class="txta" id="result"></textarea>

<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script>
function myfunction(){
document.getElementById('show').innerHTML = `
<table><tbody><tr class="newdiv"><td style="background:yellow">enter</td></tr></tbody></table> click the yellow box!
`;
}
// the script below enables typing 'enter' into textarea by clicking the yellow box.
$(document).on('click',sel);return false;
});
function insertAtCaret(areaId,text) {
  var txtarea = document.getElementById(areaId);
  if (!txtarea) {
    return;
  }
  var scrollPos = txtarea.scrollTop;
  var strPos = 0;
  var br = ((txtarea.selectionStart || txtarea.selectionStart == '0') ?
    "ff" : (document.selection ? "ie" : false));
  if (br == "ie") {
    txtarea.focus();
    var range = document.selection.createRange();
    range.moveStart('character',-txtarea.value.length);
    strPos = range.text.length;
  } else if (br == "ff") {
    strPos = txtarea.selectionStart;
  }
  var front = (txtarea.value).substring(0,strPos);
  var back = (txtarea.value).substring(strPos,txtarea.value.length);
  txtarea.value = front + text + back;
  strPos = strPos + text.length;
  txtarea.scrollTop = scrollPos;
}
</script>