The following line is giving me an InvalidCastException when trying to convert to IEnumerable type, even though I have implemented IEnumerable interface. Return New CountryInfo(CountryCodes(i), CountryNames(i)) (also in bold below)
Imports System
Imports Gaia.WebWidgets.HtmlFormatting
Imports System.Collections.Generic
Imports System.Globalization
[code]....
I have an object called Result<T> that has a constructor which accepts an argument of IEnumerable<T>. I'd like to be able to pass in a datatable if possible.
I tried datatable.AsEnumerable(), but where I bind to the data it was complaining that 'MyProperty' is not a field or property on type 'DataRow' - which makes sense since 'MyProperty' isn't a property on 'DataRow', but it was a column in my datatable.Is there a way to convert a datatable to something that I can pass into the Result object and still have it bind to, say, a gridview?
I have these errors when creating my website?
Error 1Server Error in '/ Application. -------------------------------------------------------------------------------- Conversion from type 'DBNull' to type 'String' is not valid. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.InvalidCastException: Conversion from type 'DBNull' to type 'String' is not valid. Source Error: Line 64:
Line 65:
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].....
is there a way to retrieve type T from IEnumerable<T> through reflection?
e.g.
i have a variable IEnumerable<Child> info; i want to retrieve Child's type through reflection
And here is the code that produces the error
CODE:
How can i cast this one?
While learning to use LINQ in VB.NET, I came across the following:Dim x As IEnumerable = (some LINQ query)
If you can't instantiate an interface, but only a concrete implementation of it, why is this allowed? Is there some difference between doing Dim x as (Type) and Dim x as New (Type)?
I am stuck trying to convert code that works in C to VB. The C code is:internal IEnumerable<GraphicsBase> Selection
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I have read the stuff about how this has to be done in VB using GetEnumerator method, but I just can't seem to get it to work.
In many projects I work on, whenever I have to return a read only collection, I use the IEnumerable<T> interface and make it type specific like so:
CODE:
Most of the time, I return a List but in some functions and read only properties I return an array which also serves the purpose alright by kind courtesy of Extension Methods.
My question is am I violating any design principles by returning IEnumerable<T>s instead of specific types (e.g.: List<T>, HashSet<T>, Stack<T> or Arrays)?
I keep getting this error "InvalidCastException: Conversion from string to type 'Double' is not valid." whenever I try and run this piece of code. Could someone explain to me where it is trying to make a conversion to double? No matter what I do to my input string, I get the error.Here is the stack trace:
Input string was not in a correct format.Description:An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.FormatException: Input string was not in a correct format.
[code]...
I am creating a gridview and need to gather the data from various functions that return a type of IEnumerable. I've created gridviews using a dataset as a datasource, but how does one use multiple data sources(of IEnumerable) to populate one gridview? Like how do you combine all that into one dataset?
View 1 RepliesIm trying to improve some apps ive written, the first is a console app... Im trying to get it so that i wont get an invalidcastexception if the user inputs a string, when the variable is type "Double"
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I'm a beginner to Visual Basic. In here I want to recreate a piggy bank which tells me how much money do I have. I created a function but the program tells me :
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I have used the Gridview_PageIndexChanging event in asp.net.i have used the code like this:
gridFileDetails.PageIndex = e.NewPageIndex
During the run time when i clicked the next page,it generates an error:
An exception of type 'System.InvalidCastException' occurred in FFK.DLL but was not handled in user
code
Additional information: Unable to cast
object of type
'System.Web.UI.WebControls.ContentPlaceHolder'
to type
'System.Web.UI.WebControls.GridViewRow'.
in the RowCommand event,I have used the following RowCommand event:
Protected Sub gridFileDetails_RowCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCommandEventArgs) Handles gridFileDetails.RowCommand
Dim row As GridViewRow = CType(CType(e.CommandSource, Control).NamingContainer, GridViewRow)
[code]....
I tried using the linq Zip method on IEnumerable but it does not work for more than 2 arrays.Here is an example in Python of what I am trying to do(I got p - nested IEnumerable - and need q - another nested IEnumerable):
>>> l=['a','b','c']
>>> m=[1,2,3]
>>> n=['x','y','z'][code].......
Error is Simple Application -- Error Type (A first chance exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll)
View 3 RepliesI have this issue with casting....is there anyway i could pass an integer into a label...this is what i have done so far but i am getting this error "A first chance exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll"
Dim firstNumber As Integer
Dim secondNumber As Integer
Dim solution As Integer
[CODE].........................
why I got the following (InvalidCastException was unhandled) on the following code and how can I solve the problem.
LabelPB.Text = P - Total.Text 'Conversion from string "" to type 'Double' is not valid
I am using .ToString("#,##0.00") to format a number. I'm sure I have used this before but today it doesn't work.I want to format a System.Double value from the datatable like this 12345.6789 to 12,345.68
Code:
myString = dt.Rows(i)("column_name").ToString("#,##0.00")
gives a System.InvalidCastException:Conversion from string "#,##0.00" to type 'Integer' is not valid.
Trying to insert a record into a db, but I get the following error System.InvalidCastException: Conversion from string "Duck" to type 'Integer' is not valid. ---> System.FormatException: Input string was not in a correct format."Duck" is what I entered into a LNameTextBox.
Here is the code.
Dim myCommand As OleDbCommand = New OleDbCommand("INSERT INTO [Info] ([UIN], [Last Name], [First Name], [Department Code]) VALUES (@UINValue, @LNameValue, @FNameValue, @DeptCodeValue)", myConnection)
myCommand.Parameters.Add("@UINValue", OleDbType.Integer, UINTextBox.Text, "[UIN]")
[code]....
I can't understand why it is trying to converty the Last Name textbox entry to an integer.
In my project I'm trying to get the caption property of serial ports available on computer. But when I run this code below I get "A first chance exception of type 'System.InvalidCastException' occurred in Microsoft.VisualBasic.dll" exception. I tried putting "Option Strict On" and then I'm getting build error saying it disallows Late binding.
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I want to use explicit conversion (CType function in VB.NET) to convert the variable d from double type to integer type and store the result as 132.
Imports System.Console
Module Module1
Sub Main()
[CODE]...
This is my code. But Visual Basic tells me an error: Error1Type 'i' is not defined.C:\Users\mihaispr\Desktop\Conversie explicita\Conversie explicita\Module1.vb1922Conversie explicita
1. When I try to do something like; Imports System.Collections
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I've pieced together some information from other posts but I'm stuck. The first part works fine. Basically I query the database using LINQ and then I loop through the results generating a report.
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i am getting all filenames from a directory.parsing out the directory names & the .vb extension then converting those filesnames to classes.Every file in the LPCriteria direcotry is its own class with a "Evaluate" function.[code]
View 1 RepliesPossibly a dup but I tried googling and searching here before posting. Assume a 2 column table with columns Age (int) and EmpName (string) A datatable can be converted to IEnumerable by a simple dbTable.AsEnumerable() Now to perform any Linq you must know the column names since intellisense will not pick it up due the fact that AsEnumerable has returned a bunch of datarows that you can enumerate. I have used a small 2 col table but for tables with many columns it is a pain. So most of the time we try something like
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In a VS 2008 ASP.net 3.5 aspx.vb file, Response.Write(DDL.SelectedItem) worked very well.But "Dim filenameDDL As String = DDL.SelectedItem.Text" did not. Then I tried the following codes and found the problem -- Conversion from type 'ListItem' to type 'String' is not valid.
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. I get this error: "Cannot convert lambda expression to type 'string' because it is not a delegate type" - keyword select become underlined in blue
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Above code should displays drop list of employees first name and last name in a combo box
How can I use a string parameter for a method and convert this to a type.
I am using reflection to retrieve items within an enumeration:
CODE:
Currently I am creatnig a separate method for each enumeration in order to retrieve it's values.
What I would like to do is pass the name of the enumeration as a parameter to the method and cast this as a type.
I am creating a simple console application in vb.net in order to convert a file from any type to utf8 but i can't figure out how this thing works with the encoding. I know that the source file is in Unicode, but when i convert it to a new format i get junk. Any suggestions? i am not sure if my code is correct
this is my code.
[Code]...