jQuery-自动输入文字大小（不是textarea！）

这是一个插件，可以满足您的需求：

插件：

(function($){$.fn.autoGrowInput = function(o) {    o = $.extend({        maxWidth: 1000,        minWidth: 0,        comfortZone: 70    }, o);    this.filter('input:text').each(function(){        var minWidth = o.minWidth || $(this).width(), val = '', input = $(this), testSubject = $('<tester/>').css({     position: 'absolute',     top: -9999,     left: -9999,     width: 'auto',     fontSize: input.css('fontSize'),     fontFamily: input.css('fontFamily'),     fontWeight: input.css('fontWeight'),     letterSpacing: input.css('letterSpacing'),     whiteSpace: 'nowrap' }), check = function() {     if (val === (val = input.val())) {return;}     // Enter new content into testSubject     var escaped = val.replace(/&/g, '&amp;').replace(/s/g,' ').replace(/</g, '&lt;').replace(/>/g, '&gt;');     testSubject.html(escaped);     // Calculate new width + whether to change     var testerWidth = testSubject.width(),         newWidth = (testerWidth + o.comfortZone) >= minWidth ? testerWidth + o.comfortZone : minWidth,         currentWidth = input.width(),         isValidWidthChange = (newWidth < currentWidth && newWidth >= minWidth)        || (newWidth > minWidth && newWidth < o.maxWidth);     // Animate width     if (isValidWidthChange) {         input.width(newWidth);     } };        testSubject.insertAfter(input);        $(this).bind('keyup keydown blur update', check);    });    return this;};})(jQuery);