angular自定义directive [filelistread]: 多文件上传，解决ngModel读不了上传文件的问题，并补充limit数量限制

angular-directive-filelistread2.js

/**
 * multiple files upload
 * usage:
 * <form name="form">
 *   <input type="file" multiple name="uploads" filelistread limit="8" ng-model="uploads" />
 *   <label ng-show="form.uploads.$error.limit">上传文件数量限制最多为8个</label>
 * </form>
 */
angular.module('testapp', []).directive("filelistread", function() {
	return {
		require: 'ngModel',
		scope: {
			limit: '@',
			ngModel: '='
		},
		link: function(scope, elem, attr, ctrl) {
			elem.bind('change', function(changeEvent) {
				scope.$apply(function() {
					scope.ngModel = changeEvent.target.files;
					// ctrl.$setViewValue(changeEvent.target.files);
					// scope.filelistread = changeEvent.target.files;
					if (scope.ngModel.length > scope.limit) {
					// if (ctrl.$viewValue.length > scope.limit) {
						ctrl.$setValidity('limit', false);
					} else {
						ctrl.$setValidity('limit', true);
					}
				});
			});
		}
	};
})