在加载时未选择多个选择selectedOptions的Knockout

Question

我正在为用户创建编辑表单,默认情况下不会在多选中选择用户的角色.

有两个应用程序角色:"管理员"和"主持人".示例用户具有1个角色"Administrator".默认情况下不选择此项.

http://jsfiddle.net/jgT8s/4/

HTML:

<form data-bind="with: user">
    <select id="selectRoles"
        data-bind="options: $root.allRoles, selectedOptions: Roles, optionsText: 'Name', optionsValue: 'Id'"
        multiple="true"
        size="5">
    </select>
</form>

JS:

var User = function () {
    var self = this;

    self.Id = ko.observable(1337);
    self.Username = ko.observable('pietpaulusma');
    self.Roles = ko.observableArray([{ Id: 1, Name: 'Administrator' }]);
};

function UserViewModel() {
    var self = this;

    self.user = ko.observable(new User());
    self.allRoles = ko.observableArray([{ Id: 1, Name: 'Administrator' }, { Id: 2, Name: 'Moderator' }]);
}

ko.applyBindings(new UserViewModel());

UPDATE 创建了dependentObservable并将其映射到selectedOptions

self.RoleIds = ko.dependentObservable(function () {
        return ko.utils.arrayMap(self.Roles(), function (role) {
            return role.Id;
        });
    });

工作版:http://jsfiddle.net/jgT8s/5/

Answer 1

问题是Roles包含"完整"对象,而它应该只包含值部分:

self.Roles = ko.observableArray([1]);

看看这里:http://jsfiddle.net/Vkda5/