.net - Returning A List Using Entity Framework, 'System.Collections.Generic.List Cannot Be Converted To '1-dimensional Array
May 3, 2012
i have issue returning a list in a web method. here is the code
<WebMethod()> _
Public Function getTags(para_parents As String) As List(Of getTypeDetailsByParentName_Result)()
Dim context As New PPEntities
[code]....
the error is
Value of type 'System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)' cannot be converted to '1-dimensional array of System.Collections.Generic.List(Of SaftyonRoad.getTypeDetailsByParentName_Result)'
What's really the point in using the former?It's hard to use linq if I used the former. I have to convert that to an array first which is difficult because there is no (asarray) function.I think I would change all of my code that's using System.
Collections.Specialized.StringCollection to System.Collections.Generic.List(Of String)
I have converted c# .cs to vb:= I have 6 errors on:
Red "List" says Too few type arguments to system.Collections.Generic.List(Of T)' Orange "Calendar" says Value of type 'System.Windows.Forms.Control.ControlCollection' cannot be converted to 'Form1.Kobush.Windows.Forms.Appointment'.
I have a lists of different custom classes and each must be sorted severals times before the algorithm is complete. For each sort I wrote a comparer. Sofar so good. Everything works. But: By now I have abou a dozen different comparers in more than one class and it is still getting more. I wonder if there is a way to limit the number by writing a new general function that can be used to sort all lists without the need for a specific comparer.Below is what I've got so far. But it does not work.
"System.Collections.Generic.List(Of ClassA)" can not be converted into "System.Collections.Generic.List(Of Object)."
I need to be able to tell if a property is of type List(of T)but am currently unable to. if i do
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is System.Collections.Generic.List(Of Object)
I get the following error
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is System.Collections.Generic.List(Of Object) Expression of type 'System.Reflection.PropertyInfo' can never be of type[code]......
in what situation will an item in System.Collections.Generic.List not be removed successfully?url...The way they phrase it makes me think that it is possible that a Remove operation on an item found in the List(Of T) could actually fail.
I need another (dozen) pair of eyes on this. The following code:
Interface iRuleEntity Function GetRuleViolations() As List(Of RuleViolation) End Interface Partial Public Class Feedback
[code]....
is giving me this error:'Feedback' must implement 'Function GetRuleViolations() As System.Collections.Generic.List(Of RuleViolation)' for interface 'iRuleEntity'.
vb Dim s As String = strContents '<a global variable) Dim currentPos As Int64 = 0 Dim endPos As Int64 = strContents.Length - 1 '// A dictionary, used to count the frequencies Dim characterCounter As New Dictionary(Of [String], Int64)() While currentPos <> endPos '//
[CODE]...
Gives this error: Value of type 'System.Collections.Generic.KeyValuePair(Of String, Long)' cannot be converted to 'System.Collections.DictionaryEntry'.
Public Function GetAllEmployee() As List(Of Employees) Return DB.Employees.Select(Function(q) New With {q.EmployeeID, q.LastName,q.FirstName}).ToList() End Function
I'm getting an error:
Value of type System.Collections.Generic.List(Of <anonymous type>) cannot be converted to System.Collections.Generic.List(Of NorthwindModel.Employees).
I've seen many examples in LINQ but i'm not able to reproduce the same result in vb.net.
I have following code: Dim context As New MyModel.Entities()
Dim rnd As New System.Random()Dim gardens As List(Of Tuin) = (From t In context.Gardens Where _ t.Approved = True And _ Not t.Famous = True _ Order By rnd.Next() _ Select t).ToList()
Is there an exhaustive list of all of the "base" (not used in an object-oriented sense but more in a common sense) generic types in the 4.0 .NET Framework? I have found this list that I often send newer/mid-level devs to so they can understand how non-generic types map to generic types, but this is by no means exhaustive. I'm looking for something that also includes things such as KeyValuePair<>, Tuple<>, and other basic generics that may not be very-well known. Interfaces such as IObservable<> would be nice but not necessarily required.
I have a view on some data in my database it returns the data as I would expect, for example
Call Date To From Phone Number 20/1/2010 00:00 23:59 08923233223 20/1/2010 00:00 23:59 08923233245
However when I have added this to my Entity Model and query it I get duplicate(and unexpected) data appearing
Call Date To From Phone Number 20/1/2010 00:00 23:59 08923233223 20/1/2010 00:00 23:59 08923233223
I am simply binding a Entity Data Source to this Entity but I am left scratching my head as to why the data is being returned differently
EDIT: Interestingly this can't be the result of some strange under the hood join as the row counts match as expected. I have also put together a query myself to test with the same odd results.From o In App.Entities.v_PersonalRules Where o.companyid = CompanyID Select o. I am using Visual Studio 2010, .NET 4
Dim arr1 As New List(Of Double) Dim arr2 As New List(Of Object) Dim timeStart As DateTime = Now For x As Integer = 0 To 1000000
[code]....
It involves 2 lists. The first one is 1-dimensional, the second one is 2-dimensional.The first routine (which operates on the first list) completes in about .015 seconds. The second routine (which operates on the second list), however, takes almost 10 seconds. The only difference is that the second list is 2-dimensional.Is there a way to speed this up or am I doing something wrong? I have a program that requires several 2-dimensional arrays and it's running extremely slow right now. How can I speed it up so I get the same feedback that I'd get if the lists were 1-dimensional?
I have a generic repository that I communicate with my object context with. My object context has function imports that I want to be able to call through my generic repository. Currently I call them through an "Execute" function, but this is not ideal because I have to pass in my function name and parameters as strings which can cause run-time exceptions. My function imports map to complex types.
Is there a way to do something similar to:
Dim rep As IRepository(Of ComplexType)
Dim type As ComplexType = rep.Find(where:=Function(t) t.FunctionImport(parm, parm)).First()
i have been working on a simple program but cant get my head around it. It does not show any errors at the moment but when i run it does not do the things i would like it to do. I will paste in the code first and explain it below.
[Code]...
So basically the form has help button to show instructions, quit to quit the program and check to check whether the country from listbox lstCountries matches the correct capital in lstCapitals. The idea of the program is to shuffle the items in two arraylists and then add them to seperate listboxes called lstCountries and lstCapitals. At start i used 1 dimensional array and it worked like a charm for mixing up items in arrays and then adding them to listboxes, but then the problem had to match the correct Country with correct Capital and it only worked if i picked the items on the same index such as 1 and 1(straight line). It all sounds complicated and confusing, P.S alot of code is commented out, because i have tried many ways to make it work.
I am using 2 dimensional arrays for my work. My problem working with them they are incredibly slow for my work. I am starting the array with randomly assigning values (non zero) to the array. Most of the array values are zeros as shown in below form (e.g. 5 x 5):
Is it possible to have a two-dimensional array/list/collection such as the following. The first dimension is to have 2 elements, 0 and 1. The second dimension I would like to be able to have a different number of elements for each of the elements in the first dimension. To explain better, I'd like X in array (0, X) to go up to say 4 and Y in array(1, Y) to only go up to say 2.
So there would be: array(0,0) array(0,1) array(0,2) array(0,3) array(0,4) array(1,0) array(1,1) array(1,2) But no array(1,3) or array(1,4).
I'd also need to be able to use Redim Preserve to increase the size of the second dimension for each of the first dimension's elements.
I need to put 2 different fields on the same line/row/subscript, into a one-dimensional array or list. I've done this before with a delimiter and then parsed it out later, but I wonder if there is a nicer way to do this?
We are currently converting a larger legacy application from .Net1.1 to .Net2.0, both VB. Our new standard is Generic List, instead of arrays.We are recoding component by component. And while not everything is yet stored in generic.list we end up with compile time errors.Converting from generic.list to array is supported with myGenList.ToArray().But from array to generic list isnt that easy."Value of type '1-dimensional array of something' cannot be convertet to 'System.Collection.Generic.List(of something)"I know for sertain that the array consist of the type 'something', so an runtime exception converting is ok.Is there a good way to do the workaround untill the hole application is recoded?
Does link text mean I have to return a concrete implementation? Even though I am using svcutil with the /r that includes my entites(where IMyInterface is defined). I get no errors but it changes all List(of IMyInterface) to list(of Object) and I cannot deserialize it on the client
Error: list(of object) cannot be converted to list(of IMyInterface).
I have a generic List(Of Customer). The customer class has a name, address, and phone number properties. I also have a property of another class that accepts a customer name array. I am able to do this by doing the following:
Dim names As String() Dim i As Integer = 0 'customer.GetCustomers is a List(of Customer)
[Code]....
Is there a better way to convert this to a string array?
