Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
393 views
in Technique[技术] by (71.8m points)

javascript - Set cursor position in an input text field

After a lot of search I found the following threads:

define cursor position in form input field

jQuery Set Cursor Position in Text Area

Unfortunately in none of the posts a complete form embed code or a real example is given. Now I just don't know how to include nemisj's code (on the first link) or Mark's code (on the second link) into my form:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
  <script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/jquery.validate.js"></script>

  <script>
  $(document).ready(function(){
$("#site").focus(function(){
    if( this.value == this.defaultValue ) {
        $(this).val("http://");
    }
});
  });
  </script>

</head>
<body>
<form action="#" method="post">
<input id="name" type="text" name="name" value="Name" /><br />
<input id="site" type="text" name="mail" value="Website" /><br />
<input type="submit" value="Send"> 
</form>
</body>
</html>

I wonder if someone could kindly help me with this as I'm badly stuck!

Many thanks in advance!

Here's the edited code, but it still doesn't work:

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" 
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
  <script src="http://code.jquery.com/jquery-latest.js"></script>
  <script type="text/javascript" src="http://dev.jquery.com/view/trunk/plugins/validate/jquery.validate.js"></script>

  <script>
function setCursor(node,pos){

    var node = (typeof node == "string" || node instanceof String) ? document.getElementById(node) : node;

    if(!node){
        return false;
    }else if(node.createTextRange){
        var textRange = node.createTextRange();
        textRange.collapse(true);
        textRange.moveEnd(pos);
        textRange.moveStart(pos);
        textRange.select();
        return true;
    }else if(node.setSelectionRange){
        node.setSelectionRange(pos,pos);
        return true;
    }

    return false;
}
  $(document).ready(function(){
$("#site").focus(function(){
    if( this.value == this.defaultValue ) {
    $(this).val("http://");

    var node = $(this).get(0);
    setCursor(node,node.value.length);
}
});
  });
  </script>

</head>
<body>
<form action="#" method="post">
<input id="name" type="text" name="name" value="Name" /><br />
<input id="site" type="text" name="mail" value="Website" /><br />
<input type="submit" value="Send"> 
</form>
</body>
</html>  
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

Inside your <script></script> tag is where your JavaScript goes (although we prefer putting it in a separate file, so that no JavaScript lives on the HTML page itself).

Inside that, you have a call to $(document).ready(), which passes a function() { ... }. Inside that function is all the code that will be executed when your document has loaded.

Inside that function you have a call to $('#site').focus() which itself provides a function —?this time one that will be called whenever the #site element gains focus. And presumably that's where you want to change the cursor position.

So, taking the setCursor function from Set cursor at a length of 14 onfocus of a textbox you can put that anywhere in your <script></script> and then inside that innermost function of yours you can write:

if( this.value == this.defaultValue ) {
    $(this).val("http://");

    var node = $(this).get(0);
    setCursor(node,node.value.length);
}

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...