I'm having trouble creating a sub that can create objects of a variable type on the fly. Here's an example of what I'm trying to achieve:
[Code]...
I can't get it to work. I've done a fair bit of research, and looked at generic types, reflection, and other tools, but I'm having trouble determining how best to tackle this problem.
I am still developing this function, but here is what I am intending it to do. This function will accept an Object, then try to determine its type. There are a specific set of types I am looking for: Integer, Boolean, Date, String. What I have so far is pretty privative, but it seems to be working so far:
Private Function DataType(ByVal entry As Object) As ValueType
Try
If IsNumeric(entry) Then
[Code].....
I have a class library that contains a number of classes. I would like to dynamically create an instance of one of these classes, set its properties, and call a method.
Example:
Public Interface IExample
Sub DoSomething()
End Interface
Public Class ExampleClass
[Code].....
say I have two POCOs I'm using in EF code first
Public class C1
property F1 as integer
End Class
Public class C2
property F2 as String
End Class
I want to have a function that will create a list either of C1 or C2, to be used in some generic operation, such that
[Code]...
I hope the question makes sense, anyways. I'm looking to know if in VB.NET, when we call an object's constructor, is there some kind of a reference that points back to the caller? I'm interested because of a corner case where I want the object being created to first be able to validate the existence of some data in the caller before it allows itself to be created. If this validation fails, I plan on throwing an exception. This corner case will never happen at runtime unless the object being created is used improperly by a programmer. The object being created is not inheriting the object I want it to validate, so I can't do anything with the MyBase qualifier.
It's bit of a "future-proofing" issue that I have a (bad) habit of doing. Not critical -- I can always leave stern comments behind as a last resort. Wanted to know if this was possible.
I have the following
Sub ChangeLanguage(ByVal caller As Object, ByVal lang As String)
Dim c As Control = caller.GetNextControl(caller, True)
Do Until c Is Nothing
[code].....
I call the sub with:
ChangeLanguage(Me, "en")
The problem I have is that I get the error: "Type 'caller' is not defined."If I change GetType(caller) to GetType(vbLogin) it works fine. (vbLogin is one of the forms)I need to find a way to get it working using caller though.
I am creating a class ("Class B") which is used by another class ("Class A") which instantiates it in VB.NET 3.5.I would like Class B to read a value assigned to one of its properties by Class A every time an event happens in Class B.However, I would like this property value to be dynamically assigned to the property by Class A when the event is fired in Class B.I was thinking about somehow creating a delegate function in Class A that is linked to the property in Class B so that when the event is fired in Class B it would eventually invoke the delegate in Class A so that it returns a value to Class B.I've been reading around delegates (that's how I arrived at the idea), but I am stuck on how to code this up - could someone please help with some skeleton code?
View 1 RepliesI don't know if I stated what I mean in the subject correctly, but I'm making a parsing engine similar to XML so I can implement it in my programs. What I need to know is how to make a new thing like how with XML you can declare a new XMLDocument, like
Dim XDoc as new XDocument
OR:
Dim NPoint as New Point(10,35)
With my parsing engine, I'll have a document type called EDocument and I want to be able to declare string as an EDocument like this
Dim MyDoc as New EDocument()
I have a TreeView, which contains nodes. When a user clicks on a node, corresponding CrystalReport document should be created and displayed.For example, names of my nodes are: "PeriodReport1", "PeriodReport2", "PeriodReport3". My CrystalReport documents are named same: "PeriodReport1", "PeriodReport2", "PeriodReport3".How can I create and display right type of crystal reports document? I could do something like this:
select case reportName
case "PeriodReport1"
[code].....
I am working on a ASP.NET MVC2 website. For learning. I am working with the Visual Basic language.
In a view I would like to do this:
<%: Html.EditorForEnumeracion(Function(v) v.combustible%>
So, I created an HtmlHelper extension method:
Imports System.Runtime.CompilerServices
Imports System.Linq.Expressions
Imports System.Reflection
[Code]....
I'm not having any errors from these pieces of code, they're just empty everytime. I'm wondering if I perhaps have created them incorrectly.
Dim l As New Log()
l.Log = "Attempted staff login with username [" & txtUsername.Text & "]"
l.LogId = 0
l.StaffId = 4
l.LogDate = Date.Now()
l.Insert()
.Insert() is picked up in my BLL layer by these two functions;
[Code] ......
I am creating an XML web service that passes an array of custom types. In my consuming code I am referencing the code as a web reference which I have given the namespace MYWS. Now in code I am trying to assign the results of my web service call to an array of my type like so..[code]When I do this the complier complains, saying: "Value of 1 dimensional array of my.namespace.MyClass cannot be converted to 1 dimensional array of my. namespace. MYWS.MyClass because my.namespace.MYSW.MyClass is not derived from my.namespace.MyClass"Now I understand the message, the thing is they are the same class. The class is declared in my calling code by the web service references a dll from that project. How do I tell the compiler that these are the same type?
View 1 Replieswhen calling a webmethod
[WebMethod]
public Profile synchronize(string MID, DeviceUploadData data)
The object DeviceUploadData has many properties, and a few of them are array's. My question is about the array specifically. It loses it's value once it's received on the webmethod end.This is the property inside DeviceUploadData
Private data() As DataObject
Public Property Data() As DataObject()
Get
[code]....
So the DataObject is populated with data, then once passed, on the other end, some of the DataObject properties are no longer populated. I haven't included the other properties in this example.
How can I get the name of the object that was passed byref into a method?
Example:
Dim myobject as object
sub mymethod(byref o as object)
debug.print(o.[RealName!!!!])
end sub
[code]....
I'm using this for logging. I use one method multiple times and it would be nice to log the name of the variable that I passed to it. Since I'm passing it byref, I should be able to get this name, right?This would give you the parameter name in the method and it's type, but not the name of the variable that was passed byref.
using system.reflection
Dim mb As MethodBase = MethodInfo.GetCurrentMethod()
For Each pi As ParameterInfo In mb.GetParameters()
[code]....
If you put that in "mymethod" above you'd get "o" and "Object".
I was testing article [URL] to see if I could use this to populate a listview2 with the icons from Directory.GetFiles(apath) and getDirectories. If you go into c:windowssystem32 the program will hang for about 4 mins then if you go back to windows then back to system32 you will get the error.
win32 handle that was passed to icon is not valid or is the wrong type.
This error makes no sense to me[code]...
Unable to cast object of type 'DynamicTreeNode' to type 'DynamicTreeNode'.
I have an inherited TreeView with an inherited class called DynamicTreeNode inside it. I am trying to loop through the DynamicTreeNodes in the TreeView.Nodes property which is causing this error.
I want to pass a List of T where T is an object I've created that has about ten properties (strings, dates and integers).The lst passes to the function successfully. I am also passing an New T of the Object (itm as T).I can see all the values (see image below), but because it's generic I cannot seem to retrieve the property values and I cannot figure out how to iterate through the properties of each itm as they are retrieved in the For Each.[code]
View 10 RepliesFor I = 0 To 10
If Items.Count = 0 Then Exit For
Dim T As New Thread(AddressOf Thread)
T.Start(New Object() {"Test", "Test"})
[code]....
When I put same code in empty project it works.
I've got a piece of code in a project (MyProject) that contains early bound object from a referenced assembly (We'll call it CommonAssembly):
Dim myObject As CommonAssembly.MyEarlyBoundType
now I have another assembly that is dynamically loaded because it is not present in all projects:
Dim myLateBoundObject As Object = AppDomain.CurrentDomain.CreateInstanceAndUnwrap("Utils", "Utils.MyLateBoundType")
MyLateBoundType derives from CommonAssembly.MyEarlyBoundType, and I want to cast myObject to myLateBoundObject and then programmatically invoke the additional
[Code].....
i always get this error when i tried to update my table: Unable to cast object of type 'System.Object[]' to type 'System.String[]'.
i only want to update STATUS, ENDTIME, and PRICE
the data type of each field are:
STATUS = nvarchar
ENDTIME = smalldatetime
PRICE = money
[Code]....
I have some classes, BsfciFile and StudyFlashCard. Bsfci is the extension to which I save my set of flashcards in an INI format. I am currently working to transform my code from using Windows API calls to access the INI to using a IniFile class that I found on the internet. I would like the BsfciFile to have a Array of StudyFlashCard objects, but I would like the StudyFlashCard class to use the IniFile class object contained in the BsfciFile class. I can pass the IniFile from the BsfciFile class to the constructor for the StudyFlashCard class, but I want it to modify the same IniFile as the BsfciFile class has later on.
[Code]...
when view in browser, i got this error: Unable to cast object of type 'ASP.webform1_aspx' to type 'System.Web.UI.WebControls.Button'.
how should i solve this problem?
Line 7: If Not Page.IsPostBack Then
Line 8: Dim rowIndex As Integer = 0
<b>Line 9: Dim btn As Button = DirectCast(sender, Button)</b>
[Code].....
I had write code (just for learning), the codes :
dim Temp as string
Temp = Recordset("
Table_Field")
but, when I start Debugging the error messages "Unable to cast object of type 'ADODB.InternalField' to type 'System.String"
I am implementing IMAPI2 into my vb.net project but ran into a wall. I am getting the message Unable to cast object of type 'IMAPI2FS.FsiStreamClass' to type 'IMAPI2.IStream' when trying to start the burn. I googled around and found this is something that microsoft hasn't fixed.. which basically renders IMAPI2 useless in vb.net.
I found a post on codeproject.com by eric hadden who combined the IMAPI2.dll and IMAPI2fs.dll into an c# interop file. I also see the IBURN interop in microsoft SDK samples. I'd like to use either, but it's in c# and I'm using vb express. Does anyone know a way to get the interop into visual basic or a way around "Unable to cast object of type 'IMAPI2FS.FsiStreamClass' to type 'IMAPI2.IStream'"?
I'm having a problem with converting from one source type to a destination type. I have a form with 2 buttons (button 2 uses the OpenFileDialog to have the user open an excel file set to NewFile),(button 1 takes the contents from specific cells in NewFile and arranges them how I need into oXLApp1).
The error I get is "Unable to cast object of type 'System.IO.FileStream' to type 'Excel.Application'." in line 14 of the code below.
Public Class Form1
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
[Code]....
I'm new to VB 2005, the code below is actualy coded from VB 6 and just converted it to VB 2005. I'm having trouble with line that's on bold letters.In VB 6 this works just ok. By the way the error message is "Unable to cast object of type 'System.String' to type 'ADODB.Connection'." [code]
View 5 RepliesHi
I've got a pretty general question about the best practice in passing an object reference to a Form in VB.NET. My form is a dialog and I've created an overload ShowDialog method, where I pass an Object into it ByRef.
The trouble is, I want to be able to refer to that Object throughout my dialog Class and not just in the ShowDialog method. For instance, some of my Events for controls on the form, need to reference that object.
I know I could create a local Private variable in the Class and assign it to the passed value, and then use that value. However I'm thinking this isn't very efficient because it would (I believe) create a new copy of the Object (which is a complex, large class in itself).
I can't cast my objects. I get: "Unable to cast object of type 'ClassA' to type 'ClassB'".
The service Class:
Public Class svc_Insp
Implements Isvc_Insp
Public Function Test(ByVal pm_income As ClassC) As String Implements Isvc_Insp.Test
[code]....
Unable to cast COM object of type 'System.__ComObject' to class type 'rjsDocMan.Folder'.Instances of types that represent COM components cannot be cast to types that do not represent COM components; however they can be cast to interfaces as long as the underlying COM component supports QueryInterface calls for the IID of the interface.The code where it is flagging the error is:
<div style="color: Black; background-color: White;">
treeview += AddChildren(Session("DocMan").RootFolder)
</div>
[code].....
I saw this thread and I had simple answer in mind. To use custom enumerator class. So I was trying to make one for that guy, which would have one more property to check whether its has reached end or not. It would also provide current position.I'm getting an error "Unable to cast object of type 'SZArrayEnumerator' to type 'WindowsApplication1.myEnumerator'." at the line 6 [see below].However, return type of values.getEnumerator says its IEnumerator. [code]
View 14 Replies