我想将Xamarin.Forms移动应用程序中的Parent和Child对象插入Azure Mobile Apps服务器。我可以通过TableController Post方法获得Parent和/或Child对象,但我永远不能让Child与Parent相关。
以下代码剪辑的结果是插入了Parent,但Child插入失败,因为在Parent上违反了唯一键约束(我相信它试图插入另一个Parent而不是链接)。
如果我只是尝试插入Child而不插入Parent,那么它确实插入了Parent但是有000 ... 000 Parent.Id
这似乎是一项非常常见的任务,但我找不到有用的教程或答案。我能找到的每个体面的Azure移动应用程序教程都是使用单表ToDo示例,该示例有效,但缺少关系示例。
我的服务器端型号是:
public class Parent : EntityData
{
public string Description { get; set; }
//public ICollection<Child> Childs { get; set; }
}
public class Child : EntityData
{
public string Description { get; set; }
public Parent Parent { get; set; }
}
和我的服务器TableController Post看起来像(对于Parent):
public class ParentController : TableController<Parent>
{
protected override void Initialize(HttpControllerContext controllerContext)
{
base.Initialize(controllerContext);
MyContext context = new MyContext();
DomainManager = new EntityDomainManager<Parent>(context, Request);
}
// POST tables/Parent
public async Task<IHttpActionResult> PostParent(Parent item)
{
Parent current = await InsertAsync(item);
return CreatedAtRoute("Tables", new { id = current.Id }, current);
}
}
和(对于孩子):
public class ChildController : TableController<Child>
{
protected override void Initialize(HttpControllerContext controllerContext)
{
base.Initialize(controllerContext);
MyContext context = new MyContext();
DomainManager = new EntityDomainManager<Child>(context, Request);
}
// POST tables/Child
public async Task<IHttpActionResult> PostChild(Child item)
{
Child current = await InsertAsync(item);
return CreatedAtRoute("Tables", new { id = current.Id }, current);
}
}
在Xamarin.Forms移动端,我有模型:
public class Parent
{
[JsonProperty(PropertyName = "Id")]
public string Id { get; set; }
[JsonProperty(PropertyName = "Description")]
public string Description { get; set; }
}
public class Child
{
[JsonProperty(PropertyName = "Id")]
public string Id { get; set; }
[JsonProperty(PropertyName = "Description")]
public string Description { get; set; }
public Parent Parent { get; set; }
}
和Xamarin.Forms插入命令是:
private async Task PostParentTask()
{
Parent Parent = new Parent { Description = "New Parent" };
await App.MobileService.GetTable<Parent>().InsertAsync(Parent);
await Application.Current.MainPage.DisplayAlert("Parent", string.Format("{0} was posted with GUID {1}", Parent.Description, Parent.Id), "OK");
Child Child = new Child { Description = "New Child", Parent = Parent};
await App.MobileService.GetTable<Child>().InsertAsync(Child);
}
答案 0 :(得分:1)