Change paragraph text dynamically with jQuery?

问题

I want to take the information typed into a text field and display it in a paragraph elsewhere on the page. Basically, exactly what is happening below as I'm type this (go to post a question and start typing in the main text box and you'll see what I mean).

Any idea how to do this? The page has so much JavaScript on it I can't find how they did it.

回答1:

I think you are looking for this.

Here is how your html should look like:

<textarea id="txt" style="width:600px; height:200px;"></textarea>
<p id="preview"></p>

And jQuery:

$(function(){
  $('#txt').keyup(function(){
     $('#preview').text($(this).val());
  });
});

This grabs the value of textarea on its keyup event and later the paragraph's text is changed (text() method) with that of textarea $(this).val().

回答2:

Here's an example that should just work -

<html>
<head>
 <style>
 #typing{background-color:;}
 #display{background-color:#FFEFC6;}
 </style>
 <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.js"></script>
</head>
<body>
 <div id="typing">
  <input type="text" name="typing" value="" id="typing_input" style="height:100px;width:300px;">

  </input>
 </div>
 <div id="display">
  <p id="typing_display"></p>
 </div>

 <script type="text/javascript" charset="utf-8">

   $(document).ready(function()
   {
    $('#typing_input').bind("keypress keydown", function(event) {
     $('#typing_display').text($('#typing_input').attr("value"));
    });

   });
 </script>
</body>
</html>

Sorry for the extra styles - can't help myself. Jquery's .change() won't change is until different events are fired, .live() and .bind() are what you want. There's also the .attr("value") part which sometimes does extra magic that i don't totally understand - but it does stay up to date. Best of luck!

回答3:

I would use something like keyup and update the display each time a key is released. You might also need to handle the change event in case someone pastes something into the box.

<div id="container">
<textarea id="textfield"></textarea>
<p id="displayArea"></p>
</div>

<script type="text/javascript">
    var display = $('#displayArea');
    $('#textfield').keyup( function() {
       display.text( $(this).val() );
    }).change( function() {
       display.text( $(this).val() );
    });
</script>

Also, you could look at the WMD editor, which is what SO uses. It does more than you are asking for, but you could get some ideas from it.

来源：https://stackoverflow.com/questions/3441699/change-paragraph-text-dynamically-with-jquery

标签

jquery

text

preview