指令函数在angularjs中多次调用

Question

我在anguular js中创建了一个指令来调整angularjs中的图像大小。
这是指令代码：

app.directive('resize1', function ($window) {
    return {
        restrict: 'A',
        replace: true,
        scope: {
            params: '&',
            path: '=',
            siteurl: '='
        },
        link: function($scope, element, attrs) {
            $scope.resizeImage = function() {
                var size = 0;
                var width = angular.element($window).width();
                src = $(element).attr('src');

                if (src != null || src != '') {
                    var url = parse_url(src).query;
                    var path = parse_url(src).path;

                    var str = url.split('&');
                    var link = '?';
                    $.each(str, function(index, value) {
                        pair = value.split('=');
                        if (pair[0] != 'h' && pair[0] != 'w') {

                            link = link + value + '&';
                        }
                    });

                    if (width >= 960) {
                        size = $scope.$eval($scope.params).gt960;
                        newWidth = size.w;
                        newHeight = size.h;

                    } else if (width < 960 && width >= 480) {
                        size = $scope.$eval($scope.params).bt480960;
                        newWidth = size.w;
                        newHeight = size.h;
                    } else {
                        size = $scope.$eval($scope.params).lt480;
                        newWidth = size.w;
                        newHeight = size.h;
                    }
                    link = link + 'h=' + newHeight + '&w=' + newWidth;
                    $(element).attr('src', path +  link);
                    $(element).attr('ng-src', path +  link);
                    $(element).closest('div.spinner').css({
                        'height' : newHeight,
                        'width' : newWidth,
                        'margin' : '0px auto'
                    });
                }
            };

            angular.element($window).bind('resize', function() {
                $scope.resizeImage();
            });

            $scope.$watch('path', function (){
                //alert('df');
                $scope.resizeImage();
            });
        }
    }
});

我的html是：

<div class="list-view" ng-hide="productDetail == null">
    <div class="list-view-img">
        <div class="spinner">
            <img resize1
                ng-src="{{siteurl}}thumbnails/index?file={{path}}&h=200&w=200"
                params="{lt480: {h: 300,w: 300}, bt480960: {h: 450,w: 450}, gt960: {h: 940,w: 940}}"
                path="paths.products.primary_image + productDetail.primary_image"
                siteurl="siteUrl"
            />
        </div>
    </div>
</div>

现在问题是它工作正常但是指令函数被调用了3次.. 谁能告诉我什么可能是错的？为什么它被称为三次虽然我已经调用了一次？