Is there a way to get an enum to explicitly cast to it's base type?If I have something like this:
Code:
Public Enum Packets As Byte
Stuff = &H0
End Enum
I have to do
Code:
Dim test As Byte = CByte(Packets.Stuff)
Rather than
Code:
Dim test As Byte = Packets.Stuff
I don't see why that's the way it works, since you know that the enum will always have values of the base type.
I have a URL lets say . some time i need to send HTTP and some time i need to send it to HTTPS for that i created a enum:
Private _protocol As Protocol
Enum Protocol
HTTP
HTTPS
[CODE]...
Now when i get value back from protocoltype it returns me integer value as enum do so tell me how to get string from enum or other substitute.
Dim targetUri As String = setting.protocolType & "://www.mysite.com"
Private
Sub cmdExit_Click(ByVal
sender As System.Object,
ByVal e
[code]....
I'm struggling with enums
Private Enum sizeMode
AutoSize = 2
CenterImage = 3
Normal = 0
[CODE]...
Here i'm trying to cast a string to a pictureboxsizemode: PictureBox1.SizeMode = DirectCast(DirectCast(fields(4), sizeMode), PictureBoxSizeMode)
If I defined a ENUM in a base object with serveral default values. When I inherit from the base object I want to add more options the the ENUM list which are specific to the inheriting object.
For example my base could have a ENUM called Direction with values:
None
ALL
Stop
Start
I create a new class call Compass which inherits the base class and what to add the following to the ENUM Direction. I create a new class call Navigation which inherits the base class and what to add the following to the ENUM Direction. So, In my inheriting class haow do I extend the ENUM.
The program below trhows an error in the line "mTable2 = mTable.Copy". The error is: "Unable to cast object of type 'System.Data.DataTable' to type InherintanceQuestion.InheritedTable". This is because mTables is an instance of the InheritedTable class which inherits a DataTable and mTable is a DataTable. So, is there any way I can create the mTable2 to the mTable.copy to the mTable.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[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 RepliesI 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]....
Could anyone assist me in solving my problem ? My code was written in VB (VS 2003.)I got this error: System.InvalidCastException: Cast from type 'DBNull' to type 'Integer' is not valid. in my code.Here is the code line where I am getting the error: LeadCampusID = CInt(.Item("mkCampusID"))I fixed the error by making the changes in the code as :
If Not IsDBNull(.Item("mkCampusID")) Then
LeadCampusID = CInt(.Item("mkCampusID"))
Else
[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 RepliesI have a question about ASP.Net, visual basic I have 2 LINQ query's, the first one works, the second one doesnt, produces a
"Unable to cast object of type 'System.Data.Objects.ObjectQuery'1[SelmaV2.Products]' to type 'System.Collections.Generic.List'1[System.String]'.
[Code]....
Columns 0 & 1 are filled from a DataAdapter from Access Database and three are added. I had this working, but I changed it to check for the column "Feed" so I could add several Locations. At first this worked,but I did someething in perfecting it and it now fails after filling the first row of the datagridview (dgvFdMed).I ran a check and the table LotsTab has 8 rows filled. Column 1 & 2 are strings and the database appears they are fine. The added columns have just been created with no value. My plan is to enter the values and then use the data from the grid.
Private Sub sfillGrid(ByVal Loc As String)
Dim i As Integer
Dim column As DataGridViewColumn
[code]....
I have 2 Child forms inside a parent. For example, FrmChild1 contains a "Friend Sub" I wish to call.I would like one of the child forms to call that sub from another child form (we will call it FrmChild2. The following code works, but when it's done going through the "For Each", I get a "Invalid Cast"
' THIS CODE IS IN FrmChild1
For Each mFrmChild2 As FrmChild2 In FrmParent.MdiChildren
mFrmChild2.GuestRefresh(False)
Next
Error after calls are made:"Unable to cast object of type FrmChild1 to type FrmChild2.
I have a series of API calls that are returning J# data types. I have been able to convert most of the data types (Integer, Boolean, Double, Float, etc) just fine.What I need to do now is convert a java.Util.Collection to a VB .NET collection (ArrayList)
Here is my attempt:
Public Function MakeDotNETCollection(ByVal javaCol As java.util.Collection) As Collection
Dim dotNetCol As Collection
[code]....
I keep getting a runtime error "Unable to cast object of type 'AbstractListlistIterator' to type 'System.Collections.IEnumerator.
I am building a software which will be used to create a remote desktop connection. However I'm getting this error:
Unable to cast COM object of type 'System.__ComObject' to interface type 'MSTSCLib.IMsTscNonScriptable'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{C1E6743A-41C1-4A74-832A-0DD06C1C7A0E}' failed
due to the following error: Δεν υποστηρίζεται τέτοια διασύνδεση (Exception from HRESULT: 0x80004002 E_NOINTERFACE)).
[Code]...
I am using a background worker and am attempting to use the following code. However I keep getting this error on i "Unable to cast object of type 'ObjectCollection' to type 'System.Array'."
Private Sub btnVerify_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnVerify.Click
myArray = listProxies.Items()
BackgroundWorker1.RunWorkerAsync()
End Sub
[code]....
I have a generic Class I'm using to hold information loaded from a database.I have a method which takes a DataRow as an argument, uses the object's known column name and extracts the data from the DataRow, such that:Dim loadData As T = CType(myDataRow("myColumnName"), T))works as my default assignment in most cases.Unfortunately, due to some horrifying design constraints, some of my columns may be null, and may also be taken from enumerations.This means that when <T> is Nullable(Of SomeEnumeration) the above code does not work because I can't cast 0 directly to SomeEnumeration.Zero.Is there some way to check whether <T> is Nullable(Of [Enum])? Or some way to write a method which allows Integers to be cast to Nullable(Of [Enum])?I feel like I'm forgetting something that would allow me to write one of the other of these, but my weak google-fu is turning up nothing.
EDIT: Okay, thanks to dasblinkenlight's answer below, I can detect when this circumstance is occurring, but what I need to do now is to take a type <T> which I know is Nullable(Of SomeClass), get a type reference to SomeClass and then create a new object of type Nullable(Of SomeClass) and assign that to LoadData.My problem was that I had a lot of difficulty in finding any function which would accept baseType as an actual Type.Parse accepted baseType as a parameter, I knew baseType was an [Enum] type because of dasblinkenlight's code, so I was, in this instance, able to code a solution. It's a solution which is very specific to my problem (i.e., T is Nullable(of SomeEnumeration)), but it's a solution nonetheless.
I have given reference to Microsoft HTML in COM (am using VB 2008)
"Unable to cast object of type 'System.Windows.Forms.HtmlElement' to type 'mshtml.IHTMLElement'."
I want to retrieve all the properties like the class name, html id of every object in the web browser. I am getting the above exception when i try to direct cast it.[code]...
I have a number of controls (Device1, Device2, etc.) that all inherit from BaseDeviceControl. In the DragEnter event handler I am trying to test for the correct type by using the BaseDevvceControl like this....
[Code]....
I have a copy function that I'd like to override in subclasses to return the type of the subclass. Here are my interfaces:
Public Interface IBase(Of T)
Function Copy() As T
End Interface
[Code]....
when I search for a customer, it can search but the problem is that when I search for customer and I wanted to update or delete, It has an error which says "OleDbCommand.Prepare method requires all parameters to have an explicitly set type." What does that mean? Here is the code that I am using:
Public Class EditingCust
Dim cmd As OleDbCommand
Dim myAdapter As New OleDbDataAdapter[code].....
cast integer values to an array of enum values?
View 2 RepliesI have been trying to use vb2008 to automatically update CustomDocumentProperties fields that I have set up within a pro-forma document. I can load the Word application and word document without problems.I want to update the CustomDocumentProperties fields with data read from a dB. To do this I am assuming that I need to iterate through the CustomDocumentProperties fields within the word document and when one is "found" that matches the data I wish to merge then assign the dB value to the field.The problem is that I am getting an exception error when I try to reference the document customdocumentproperties
"Error : Unable to cast the COM object of type 'System._ComObject' to interface type 'Microsoft.Office.Interop.Word.CustomProperties'. ...... "
my code looks like;
Dim WordApp As Word._Application
Dim odoc As Word._Document
Dim BContinue As Boolean = True
[code].....
1) VB Allows non-type template parameters2) VB supports explicit specialization 3) VB allows the type parameters to be used as the base class for the generic type4) VB allows a generic type parameter itself to to be a generic 5) VB enforces that all codes are valid for all types of parametrs
View 1 Repliesi want to know how to type cast to user defined type in vb.net.I have a mark object which contains student id , subject name,subject id and mark. I have to read the subject id from a combo box and read corresponding mark value from it to a text box.
View 2 Replies