1
我使用Northwind数据库,尝试了解Asp.Net的WebAPI。ASP.Net WebAPI URL不返回任何数据
我的模型/控制器/全局文件如下所示。
当我浏览到本地主机:XXXX/API /员工/ 5它正确地去到正确的控制器:
' GET /api/employees/5
Public Function GetValue(ByVal ID As Integer) As Employee
Dim emp As Employee = db.Employees.Find(ID)
Return emp
End Function
...但是EMP返回Null /无。
Northwind数据库中肯定有数据:
任何人都可以看到我要去哪里错了吗?
谢谢,马克
型号/ Employee.vb:
Imports System.Data.Entity
Namespace MvcApplication21
Public Class Employee
Public Property EmployeeID() As Integer
Public Property FirstName() As String
Public Property LastName() As String
End Class
Public Class EmployeeDBContext
Inherits DbContext
Public Property Employees() As DbSet(Of Employee)
End Class
End Namespace
控制器/ EmployeesController.vb
Imports System.Web.Http
Imports MvcApplication21
Imports MvcApplication21.MvcApplication21
Public Class EmployeesController
Inherits ApiController
Private db As New EmployeeDBContext
' GET /api/employees
Public Function GetValues() As IEnumerable(Of String)
Return New String() {"value1", "value2"}
End Function
' GET /api/employees/5
Public Function GetValue(ByVal EmployeeID As Integer) As Employee
Dim employee As Employee = db.Employees.Find(EmployeeID)
Return employee
End Function
Web.config文件:
<configuration>
<connectionStrings>
<add name="DefaultConnection" connectionString="Data Source=.\SQLEXPRESS;Initial Catalog=Northwind;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>
Global.asax.vb
Imports System.Web.Http
Imports System.Web.Optimization
Public Class WebApiApplication
Inherits System.Web.HttpApplication
Shared Sub RegisterGlobalFilters(ByVal filters As GlobalFilterCollection)
filters.Add(New HandleErrorAttribute())
End Sub
Shared Sub RegisterRoutes(ByVal routes As RouteCollection)
routes.IgnoreRoute("{resource}.axd/{*pathInfo}")
routes.MapHttpRoute(_
name:="DefaultApi", _
routeTemplate:="api/{controller}/{id}", _
defaults:=New With {.id = RouteParameter.Optional} _
)
routes.MapRoute(_
name:="Default", _
url:="{controller}/{action}/{id}", _
defaults:=New With {.controller = "Home", .action = "Index", .id = UrlParameter.Optional} _
)
End Sub
的你在顶部显示的两个GetValue函数和EmployeesController.vb是不同的 –
你怎么知道它返回null?您使用什么代码来制作HTTP请求?您是否尝试过使用提琴手查看电线上的请求? –
嗨达雷尔 - 是的,在Internet Explorer中它打开一个文本文件,它的所有内容都是NULL - F12的IE工具中的请求是:密钥\t值 请求\t GET/api/employees/5 HTTP/1.1 - 答复机构是空的 – Mark