我觉得我错过了一些非常基本的东西,但是我无法使用下拉菜单来工作,因为我期望使用Knockout.js.
我有一组要在菜单中显示的对象,我需要找到所选的选项并将其发布到服务器.我可以让菜单渲染,但似乎无法获得所选项目的值.我的视图模型如下所示：
function ProjectFilterItem( name,id ) {
this.Name = name;
this.Id = id;
}
function Filterviewmodel() {
this.projectFilters = ko.observableArray([
new ProjectFilterItem( "foo","1" ),new ProjectFilterItem( "bar","2" ),new ProjectFilterItem( "baz","3" )
]);
this.selectedProject = ko.observable();
}
ko.applyBindings( new Filterviewmodel() );
我的视图标记看起来像这样：
<select
id = "projectMenu"
name = "projectMenu"
data-bind = "
options: projectFilters,optionsText: 'Name',/* I have to enquote the value or I get a JS error */
optionsValue: 'Id',/* If I put 'selectedProject here,nothing is echoed in the span below */
optionsCaption: '-- Select Project --'
"
></select>
<b>Selected Project:</b> <span data-bind="text: selectedProject"></span>
如何让选定的菜单项显示在范围内,并发布到服务器？ (我假设我在span中渲染的observable与我发布的相同.)我是否需要ProjectFilterItem中的另一个属性,如this.selected = ko.observable(false); ？如果是这样,我将如何将其声明为值的目标？
解决方法
您只需使用
value binding绑定选定的值：
Note: For a multi-select list,to set which of the options are
selected,or to read which of the options are selected,use the
selectedOptions binding. For a single-select list,you can also read
and write the selected option using the value binding.
在你的例子中：
<select
id = "projectMenu"
name = "projectMenu"
data-bind = "
value: selectedProject,options: projectFilters,optionsValue: 'Id',optionsCaption: '-- Select Project --'
"
></select>
见Demo.
