相关疑难解决方法(0)

我的md-select设置如下:

<md-select placeholder="Category" ng-model="current.Category" flex >
    <md-option ng-repeat="item in categories" ng-value="{{item}}">{{item.Name}}</md-option>
</md-select>

@scope.categories 价值是

[  
{  
  "Name":"Commercial & Industrial",
  "ParentId":null,
  "Categories":[  
     {  
        "Name":"Deceptive Marketing",
        "ParentId":19,
        "Categories":[  

        ],
        "Id":24,
        "ModifiedDate":"2015-08-06T07:49:53.0489545",
        "CreatedDate":"2015-08-06T15:49:51.707"
     },
     {  
        "Name":"Aggressive Agents",
        "ParentId":19,
        "Categories":[  

        ],
        "Id":25,
        "ModifiedDate":"2015-08-06T07:50:10.0026497",
        "CreatedDate":"2015-08-06T15:50:08.63"
     }
  ],
  "Id":19,
  "ModifiedDate":"08/06/2015 @ 7:49AM",
  "CreatedDate":"08/06/2015 @ 3:49PM"
 },
 {  
  "Name":"Competitive Supply",
  "ParentId":null,
  "Categories":[  
     {  
        "Name":"Security Deposit",
        "ParentId":20,
        "Categories":[  

        ],
        "Id":21,
        "ModifiedDate":"2015-08-06T07:49:30.3966895",
        "CreatedDate":"2015-08-06T15:49:25.8"
     },
     {  
        "Name":"Meter",
        "ParentId":20,
        "Categories":[  

        ],
        "Id":22,
        "ModifiedDate":"2015-08-06T07:49:34.6571155",
        "CreatedDate":"2015-08-06T15:49:33.3"
     },
     {  
        "Name":"Bill",
        "ParentId":20,
        "Categories":[ …