跨WCF数据服务的动态连接
我正在通过WCF数据服务原型化一个通用数据浏览器 用户可以从树视图中选择实体,因此我不能硬编码查询结果类型,而必须动态编码查询(URI或LINQ) 为了提供跨不同数据服务的联接,我正在将每个数据服务的结果加载到客户端,并尝试动态联接它们:跨WCF数据服务的动态连接,wcf,wcf-data-services,dynamic-linq,Wcf,Wcf Data Services,Dynamic Linq,我正在通过WCF数据服务原型化一个通用数据浏览器 用户可以从树视图中选择实体,因此我不能硬编码查询结果类型,而必须动态编码查询(URI或LINQ) 为了提供跨不同数据服务的联接,我正在将每个数据服务的结果加载到客户端,并尝试动态联接它们: Dim q1 As IQueryable = ctx.Execute(Of Object)(New Uri("Service1.svc/Customers")).ToList.AsQueryable Dim q2 As IQueryable = ctx.Ex
Dim q1 As IQueryable = ctx.Execute(Of Object)(New Uri("Service1.svc/Customers")).ToList.AsQueryable
Dim q2 As IQueryable = ctx.Execute(Of Object)(New Uri("Service2.svc/Orders")).ToList.AsQueryable
Dim j = q1.JoinDynamic("q1", q2, "q2", "q1.CustomerID", "q2.CustomerID", "New (q1.CustomerID as q1id, q1.CompanyName as CompanyName)")
我在使用dynamich连接时遇到问题。见:
作为一种解决方法,我通过内存中的程序集动态创建了连接代码。 这似乎很有效。 我可以在调试器中看到连接结果。 我只是不知道如何将结果绑定到DataGrid
Dim codeDomProvider = New VBCodeProvider
Dim cp As New Compiler.CompilerParameters
cp.GenerateExecutable = False
cp.GenerateInMemory = True
cp.CompilerOptions = "/optionexplicit- /optionstrict-"
cp.ReferencedAssemblies.Add(IO.Path.ChangeExtension(My.Application.Info.AssemblyName, "exe"))
cp.ReferencedAssemblies.Add("System.dll")
cp.ReferencedAssemblies.Add("System.Core.dll")
cp.ReferencedAssemblies.Add("System.Data.Services.Client.dll")
Dim sb = New Text.StringBuilder()
sb.Append("Imports System" & vbCrLf)
sb.Append("Imports System.Linq" & vbCrLf)
sb.Append("Imports " & My.Application.Info.AssemblyName & vbCrLf)
sb.Append("Public Class JoinHelper" & vbCrLf)
sb.Append("Public Shared Function GetData() As Object" & vbCrLf)
sb.Append(" Dim ctx1 As New NorthwindDataService.NorthwindEntities(New Uri(""http://localhost:3631/NorthwindDataService.svc/""))" & vbCrLf)
sb.Append(" Dim ctx2 As New SalesDataService.SalesEntities(New Uri(""http://localhost:4354/SalesDataService.svc""))" & vbCrLf)
sb.Append(" Dim q1 as System.Data.Services.Client.QueryOperationResponse (of NorthwindDataService.Customers) = ctx1.Execute(Of NorthwindDataService.Customers)(New Uri(""Customers"", UriKind.Relative))" & vbCrLf)
sb.Append(" Dim q2 as System.Data.Services.Client.QueryOperationResponse (of SalesDataService.CustomerSize) = ctx2.Execute(Of SalesDataService.CustomerSize)(New Uri(""CustomerSize"", UriKind.Relative))" & vbCrLf)
sb.Append(" Dim j = From c In q1 Join s In q2 On c.CustomerID Equals s.CustomerID Select New With {c.CompanyName, s.Size}" & vbCrLf)
'sb.Append(" return j.tostring" & vbCrLf)
sb.Append(" return j" & vbCrLf)
'sb.Append(" r = j.ToList" & vbCrLf)
'sb.Append(" return r" & vbCrLf)
sb.Append("End Function" & vbCrLf)
sb.Append("End Class" & vbCrLf)
sb.Append(vbCrLf)
Dim code = sb.ToString
Dim compilerResults = codeDomProvider.CompileAssemblyFromSource(cp, code)
If compilerResults.Errors.HasErrors Then
Throw New ApplicationException(compilerResults.Errors.Item(0).ToString)
End If
Dim o = compilerResults.CompiledAssembly.CreateInstance("JoinHelper")
Dim t = o.GetType
Dim j = t.InvokeMember("GetData", Reflection.BindingFlags.InvokeMethod, Nothing, o, Nothing)
DataGrid1.ItemsSource = j