JS无法获取display为none的隐藏元素的宽度和高度的解决方案

在实际开发中会遇到确实需要获取隐藏元素的宽高，这儿所说的隐藏元素是display为none的元素。

可使用jQuery Actual Plugin插件来完成，其源码如下：

    ;( function ( factory ) {
    if ( typeof define === 'function' && define.amd ) {
        // AMD. Register module depending on jQuery using requirejs define.
        define( ['jquery'], factory );
    } else {
        // No AMD.
        factory( jQuery );
    }
    }( function ( $ ){
      $.fn.addBack = $.fn.addBack || $.fn.andSelf;
    
      $.fn.extend({
    
        actual : function ( method, options ){
          // check if the jQuery method exist
          if( !this[ method ]){
            throw '$.actual => The jQuery method "' + method + '" you called does not exist';
          }
    
          var defaults = {
            absolute      : false,
            clone         : false,
            includeMargin : false,
            display       : 'block'
          };
    
          var configs = $.extend( defaults, options );
    
          var $target = this.eq( 0 );
          var fix, restore;
    
          if( configs.clone === true ){
            fix = function (){
              var style = 'position: absolute !important; top: -1000 !important; ';
    
              // this is useful with css3pie
              $target = $target.
                clone().
                attr( 'style', style ).
                appendTo( 'body' );
            };
    
            restore = function (){
              // remove DOM element after getting the width
              $target.remove();
            };
          }else{
            var tmp   = [];
            var style = '';
            var $hidden;
    
            fix = function (){
              // get all hidden parents
              $hidden = $target.parents().addBack().filter( ':hidden' );
              style   += 'visibility: hidden !important; display: ' + configs.display + ' !important; ';
    
              if( configs.absolute === true ) style += 'position: absolute !important; ';
    
              // save the origin style props
              // set the hidden el css to be got the actual value later
              $hidden.each( function (){
                // Save original style. If no style was set, attr() returns undefined
                var $this     = $( this );
                var thisStyle = $this.attr( 'style' );
    
                tmp.push( thisStyle );
                // Retain as much of the original style as possible, if there is one
                $this.attr( 'style', thisStyle ? thisStyle + ';' + style : style );
              });
            };
    
            restore = function (){
              // restore origin style values
              $hidden.each( function ( i ){
                var $this = $( this );
                var _tmp  = tmp[ i ];
    
                if( _tmp === undefined ){
                  $this.removeAttr( 'style' );
                }else{
                  $this.attr( 'style', _tmp );
                }
              });
            };
          }
    
          fix();
          // get the actual value with user specific methed
          // it can be 'width', 'height', 'outerWidth', 'innerWidth'... etc
          // configs.includeMargin only works for 'outerWidth' and 'outerHeight'
          var actual = /(outer)/.test( method ) ?
            $target[ method ]( configs.includeMargin ) :
            $target[ method ]();
    
          restore();
          // IMPORTANT, this plugin only return the value of the first element
          return actual;
        }
      });
    }));

使用实例:

    //get hidden element actual width
    $('.hidden').actual('width');
    
    //get hidden element actual innerWidth
    $('.hidden').actual('innerWidth');
    
    //get hidden element actual outerWidth
    $('.hidden').actual('outerWidth');
    
    //get hidden element actual outerWidth and set the `includeMargin` argument
    $('.hidden').actual('outerWidth',{includeMargin:true});
    
    //get hidden element actual height
    $('.hidden').actual('height');
    
    //get hidden element actual innerHeight
    $('.hidden').actual('innerHeight');
    
    //get hidden element actual outerHeight
    $('.hidden').actual('outerHeight');
    
    // get hidden element actual outerHeight and set the `includeMargin` argument
    $('.hidden').actual('outerHeight',{includeMargin:true});
    
    //if the page jumps or blinks, pass a attribute '{ absolute : true }'
    //be very careful, you might get a wrong result depends on how you makrup your html and css
    $('.hidden').actual('height',{absolute:true});
    
    // if you use css3pie with a float element
    // for example a rounded corner navigation menu you can also try to pass a attribute '{ clone : true }'
    // please see demo/css3pie in action
    $('.hidden').actual('width',{clone:true});

插件地址：http://dreamerslab.com/works