Kendo网格服务器端筛选将空作为筛选对象发送到后端

使用Kendo AngularJS和ASP.NET MVC,我试图将网格的filters对象发送到后端。但是,即使我将serverFiltering设置为true,在前端生成的任何过滤器在请求中都是空的。

grid.dataSource = new kendo.data.DataSource({
    serverFiltering: true,
    transport: {
        read: {
              url: "api/foo",
              dataType: "json",
              type: "POST"
              }
     },
     schema: {
          data: "data", // records are returned in the "data" field of the response      
          total: "total"
    }
    });

//set grid to filterable
grid.filterable = {
    mode: 'row',
    operators: {
         string: {
                 contains: "contains"
                 }
     }
 };

我看了一眼 similar question 但这对我没有帮助,因为我无法复制作为公认答案列出的解决方案