我从脚本创建了 textarea 扩展器，但之后它没有扩展

) But after When i write in the textarea it doesn't expands.Why?

这是我的脚本:

<script src='js/jquery.textarea-expander.js'></script>
<script >$(document).ready(function() { 
var regex,v,l,c,b;

$( "#wnd_Addparam" ).dialog({
            autoOpen: false,
            height: 'auto',
            width: 350,
            modal: true,
            resizable:false,
            buttons: {
                "Add": function() {
                                 contapara=(parseInt(contapara)+1);

                document.getElementById("sorpara").innerHTML+="<li id="inputp"+contapara+"_id" class="ui-state-default"><span class="ui-icon ui-icon-arrowthick-2-n-s"></span>"+txt_idparam.value+"</li>";    
                $('#formp').submit();
                                $( this ).dialog( "close" ); 
                                   },
                Cancel: function() {
                    $( this ).dialog( "close" );
                }
            },
            close: function() {
                $( this ).dialog( "close" );
            }
        });

        $( "#btn_Addpar" ).click(function() {
                        i=(parseInt(contapara)+1);

    $('#wnd_Addparam').append('<form method="GET" id="formparam"><table><tr><td><label> ID  </label></td><td><textarea class="expand" id="inputp'+i+'_id" class="text"> </textarea></td></tr><tr><td><label>Type</label></td><td><select id="inputp'+i+'_type"><option value="text">Text</option><option value="integer">Integer</option><option value="float">Float</option><option value="list_values">List of values</option><option value="range">Range</option><option value="selection_collapsed">Selection (collapsed)</option><option value="selection_expanded">Selection (expanded)</option><option value="subimage">Subimage selection</option><option value="polygon">Polygon selection</option><option value="horizontal_separator">Horizontal separator</option></select></td></tr><tr><td> <label > Description</label></td> <td><textarea class="expand" id="inputp'+i+'_description" size=24></textarea></td></tr><tr><td><label>Value</label></td><td><textarea class="expand" id="inputp'+i+'_value"></textarea></td></tr><tr><td><label>Info (help)</label></td><td><textarea class="expand" id="inputp'+i+'_info"></textarea></td></tr><tr><td><label> Visible?</label></td><td><input type="checkbox" id="inputp'+i+'_visible"></td></tr></table>/form>');
                $( "#wnd_Addparam" ).dialog( "open" );
            });});</script>

插件扩展器..

/**
* TextAreaExpander plugin for jQuery
* v1.0
* Expands or contracts a textarea height depending on the
* quatity of content entered by the user in the box.
*
* By Craig Buckler, Optimalworks.net
*
* As featured on SitePoint.com:
* http://www.sitepoint.com/blogs/2009/07/29/build-auto-expanding-textarea-1/
*
* Please use as you wish at your own risk.
*/
/**
* Usage:
*
* From JavaScript, use:
* $(<node>).TextAreaExpander(<minHeight>, <maxHeight>);
* where:
* <node> is the DOM node selector, e.g. "textarea"
* <minHeight> is the minimum textarea height in pixels (optional)
* <maxHeight> is the maximum textarea height in pixels (optional)
*
* Alternatively, in you HTML:
* Assign a class of "expand" to any <textarea> tag.
* e.g. <textarea name="textarea1" rows="3" cols="40" class="expand"></textarea>
*
* Or assign a class of "expandMIN-MAX" to set the <textarea> minimum and maximum height.
* e.g. <textarea name="textarea1" rows="3" cols="40" class="expand50-200"></textarea>
* The textarea will use an appropriate height between 50 and 200 pixels.
*/
(function($) {
// jQuery plugin definition
$.fn.TextAreaExpander = function(minHeight, maxHeight) {
var hCheck = !($.browser.msie || $.browser.opera);
// resize a textarea
function ResizeTextarea(e) {
// event or initialize element?
e = e.target || e;
// find content length and box width
var vlen = e.value.length, ewidth = e.offsetWidth;
if (vlen != e.valLength || ewidth != e.boxWidth) {
if (hCheck && (vlen < e.valLength || ewidth != e.boxWidth)) e.style.height = "0px";
var h = Math.max(e.expandMin, Math.min(e.scrollHeight, e.expandMax))+2;
e.style.overflow = (e.scrollHeight > h ? "auto" : "hidden");
e.style.height = h + "px";
e.valLength = vlen;
e.boxWidth = ewidth;
}
return true;
};
// initialize
this.each(function() {
// is a textarea?
if (this.nodeName.toLowerCase() != "textarea") return;
// set height restrictions
var p = this.className.match(/expand(d+)-*(d+)*/i);
this.expandMin = minHeight || (p ? parseInt('0'+p[1], 10) : 0);
this.expandMax = maxHeight || (p ? parseInt('0'+p[2], 10) : 99999);
// initial resize
ResizeTextarea(this);
// zero vertical padding and add events
if (!this.Initialized) {
this.Initialized = true;
$(this).css("padding-top", 0).css("padding-bottom", 0);
$(this).bind("keyup", ResizeTextarea).bind("focus", ResizeTextarea);
}
});
return this;
};
})(jQuery);
// initialize all expanding textareas
jQuery(document).ready(function() {
jQuery("textarea[class*=expand]").TextAreaExpander();
});

推荐答案

插件会在 document.ready 上准备 textarea，因此在 document.ready 触发后该类分配给的任何 textarea 都不会受到插件的影响 - 但是，你可以直接调用插件而不是添加类:

jQuery(".expand").TextAreaExpander();