I using Microsoft.Office.Interop.Excel I get returned a 2D array of type object[,] which contains double for elements. Note that the index lower bound is 1 instead of the default 0, but I can deal with that easily. How can nicely convert the array into double[,] using .NET 3.5. (by nicely I mean concise, or compact).
[Code]...
I would like to cast a double to an integer, but rather than keep the numerical value the same I want to keep the bit pattern the same (this is for a compression algorithm), is this already possible in VB.net, or would I need to try and come up with my own method for doing this?
View 3 RepliesI am currently going through a book on beginning VB,NET and am trying to complete one of the exercises in the book. I have created a function that validates user entries to check that they are numeric and within certain a range.If text value is entered into the textbox I get an exception error saying that
"Cast from String to type double is not valid"
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.Cast(Of Double) extension method not working in a particular situation.However I can get my own extension method .CastToDouble working.Would you call this a Framework bug?see the commented out line of code in the code below.Similar code posted in my last post in this thread: http:[url].....
Option Strict On
Option Explicit On
Option Infer Off[code]......
Private
Sub cmdExit_Click(ByVal
sender As System.Object,
ByVal e
[code]....
I have
Public stack() As CTest
I want
Public stack() As Object
The latter is giving the error "Unable to cast object of type 'Object' to 'CTest'." when used:
Dim thestack As CTest() = testdatabase.getStack
Where testdatabase.getStack simply returns stack();
Public Function getStack() As Object()
Return stack
End Function
This fixes it, but it's not ideal (for me personally):
Dim thestack As Object() = testdatabase.getStack
So if I could keep the variable as-is (Public stack() As Object) and then do something along the lines of class.stack() = CTest I should be able to do Dim thestack As CTest() = testdatabase.getStack because the object array will programmatically have changed from Object to CTest.
I get an Invalid Cast Exception - Conversion from string to double not allowed. I don't know what to do.
Option
Strict
On[code]......
In C# we can do something like this:
Honda a = new Car(); and that works but the same one doesn't work in Visual Basic.NET (I am fairly new to Visual Basic)
Dim a as Honda = new Car and it says Unable to cast object of type 'SampleApp.Car' to type 'SampleApp.Honda'.
Here is my sample code:
Module Module1
Sub Main()
Dim a As B = New A
[Code]....
Suppose I have a list of Cat.
Public Class Cat
Public Property id As Guid
Public Property name As String
Public Property race As catRace
End Class
How can I quickly transform this List(Of Cat) into a List(Of Guid) using the id property?
I could do :
Dim newList As List(Of Guid)
For each item in catList
newList.Add(item.id)
Next
But I think there must be a way to do this faster (1 LOC). I just can't find how.
I have a method which receives an object as parameter. This object is always of a class I have created, it will never be something simple as string, integer, etc
In my simple example I have created a class called ClassThatWillBeUpdated that requires a type for some reason not shown in the example
Public Class ClassThatWillBeUpdated(Of T)
Private _count As Integer = 0
Public Property Count() As Integer
[Code]....
Or maybe it would be possible to call the DoWork(of T)(item) directly when creating the thread, but as far as I know it's not possible to make a thread run a method that has (of T) as that is basically what I'm looking for
Needless to say, the above code would fail during compile as I have no idea how to do it, if it's even possible. I'm using .net framework 3.5
All I am trying to do is select one school id. Do you know where I went wrong? ty
Public Function findId(ByVal table_name As String, ByVal name As String)
Try
con.ConnectionString = connection_String
[Code]......
unable to cast object of type dataset to type datatable.Dim dataTable As DataTable = DirectCast(dataGrid.DataSource, DataTable)
View 4 RepliesI am getting this error Cast from string "" to type 'Double' is not valid.Here is my coding:
Private Sub btnCalculate_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCalculate.Click
Dim intSqft As Integer
intSqft = Val(txtl1.Text) * txtw1.Text
[Code]...
Is this code you have obtained from elsewhere? Have you tried debugging it line by line? Which line throws the error?
View 2 RepliesI am new in programming with VS2008. Nowdays I try to built a simulation of graphics movement. I use Panel to draw the graphics but I faced a problem when I want to move the object. There were a message
"Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.PaintEventArgs'.".
Public Class Form1
Dim x, y As Integer
Dim n As Integer
Dim xp, yp As Integer
Dim xt, yt As Integer
[Code] .....
In the code base I'm working in there have a method that has the signature
Public Sub SetDropDownValue(Of T As Structure)(ByVal target As ListControl, ByVal value As Nullable(Of T))
The method I am writing is passed a parameter of type object.
How can I cast the object into something that can be passed into the SetDropDownValue method?
I am using reflection to get an object's type, or for this issue an object that has instance properties type, at runtime and then I need to change an existing variable's type into that newly found type. Is this possible? For example, the following code does not work in the line indicated within:
Public Sub DoSomething(x As T, y As T, exp As String)
'This is a instance property on the object of a different type
'i.e. 'T.AnotherType' We need to reflect to find out what type of object
[code].....
How to cast Datagridview.selectedRow(0).databounditem in Object Classes as we do in C#[code]...
View 2 Repliesi am trying to create an sql parameter but i am having an error. it gives me an error like this: Unable to cast object of type 'System.Boolean' to type 'System.Data.SqlClient.SqlParameter'. on all of this line
Dim paramcollection As New List(Of SqlParameter) ' no error on this part but the lines below gives me an error:
paramcollection.Add(New SqlParameter("@CGLCode", SqlDbType.VarChar).Value =
[Code].....
I have do the coding to export the data from DataGridView to Excel. But If am running the code am getting the below error.
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I seem to have broken something I get this error Unable to cast object of type System.EventArgs' to type 'System.Windows.Forms.KeyPressEventArgs'.
my code:
Private Sub ListControl_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ListControl.SelectedIndexChanged
[code].....
I want to do something like this:
Dim selectedCourses As List(Of Guid) =
From item In chkListCourses.Items Where item.Selected =
True Select item.Value
But I get the error:
Unable to cast object of type
'WhereSelectEnumerableIterator2[System.Object,System.Object]'
to type
'System.Collections.Generic.List1[System.Guid]'.
The value of item is a string representation of a Guid. I'd also like the syntax for a Lambda expression.
I have a base class called Schedule and three classes inherited: DailySchedule, WeeklySchedule, MontlySchedule. Now I would like to build a form in which users can modify the schedule and I have to compile different parts of it depending on whether the schedule is daily, weekly or monthly. Then I want to have back the schedule modified. Which object can I use on the form?
I thought to implement on the base class an interface iSchedule and to pass the interface to the form, but when I'm on the form constructor how can I cast the interface to the correct class? e.g. in the form constructor I will have a sched variable as iSchedule, I can see that, for example, is a DailySchedule from an interface property called Type. But how can I cast the interface to an instance of the DailySchedule class and to access to its members?
i write this code to work with some radio button and calculate Score for a questionare : Dim SScore AsByte = 0 Dim BTNN AsByte = 0 Dim BTNNS AsString = "" ForEach rBTN AsRadioButtonInMe.Controls If Mid(rBTN.Name, 1, 5) = "RBS01"Then If rBTN.Checked Then SScore = SScore + CType(Mid(rBTN.Name, 7, 1), Byte) EndIf EndIf Next I get this error on line 4 : Unable to cast object of type 'System.Windows.Forms.Button' to type 'System.Windows.Forms.RadioButton'. i dont know what is it and how can handle it.
View 5 RepliesUnable to cast object of type 'Panel1' to type
[Code]...
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 am working in VB.net and have a Class, Foo, that implements an interface, IBar.I have a List of Foo's, but I need to pass a list of IBar's into a function, but I keep getting casting errors, even when I use DirectCast.My code is [code]MainWorks works, but it would be really annoying and inefficient to have to do that everywhere I want to call this function.
View 4 RepliesI am having problems with my code, where I get the "Object cannot be cast from DBNull to other types" message when Insert(). I get the message on every Insert to this table, even though the data is successfully inserted. If I Update the same data after Insert(), it does so without error. I have checked my values and none of them are DBNull. Even when the same values are passed on Insert that are passed on Update.
My code is :
Private Sub Save()
Dim bo As tbl_GL
bo = New tbl_GL()
bo.ConnectionString = AppConfig.ConnectString
[Code] .....
Why is this query not working
Private mapOverlays As New List(Of GMapOverlay)
Dim mapOverlay = mapOverlays.Where(Function(x) x.Id = overlay.Name).Distinct()
DirectCast(mapOverlay,GMapOverlay).IsVisibile = False
I am getting the error
Unable to cast object of type
'd__7a`1[GMap.NET.WindowsForms.GMapOverlay]' to type
'GMap.NET.WindowsForms.GMapOverlay'.
I'm having a real problem with serializing data. I understand that its designed to basically copy the structure and data of a structure. In my case, I have the state of a DVD that i would like to save (persist) to disk. [Code] error: 'Error Generating XML', Inner Exception: "Unable to cast COM object of type 'System.ComObject' to class type 'DirectShowLib.DVDState'.
COM components that enter the CLR and do not support IProvideClassInfo or that do not have any interop assembly registered will be wrapped in the ComObject type. Instances of this type cannot be cast to any other class; however they can be cast to interfaces as long as the underlying COM component supports QueryInterface calls for the IID of the interface."