Is there a robust way to get a constructor with string parameter by reflection?I have no choice, but instantiate a class without knowing if the constructor belongs to it, a base class, or come intermediate class in the inheritance chain.
View 1 RepliesI have this code to get the default constructor:
Public Function f(ByVal t As System.Type) As Object
Return t.GetConstructor(New System.Type() {}).Invoke(New Object() {})
End Function
I need to pass values to the Constructor as
Public Function f(ByVal t As System.Type) As Object
Return t.GetConstructor(New System.Type() {someInteger,someString,etc.etc}).Invoke(New Object() {})
End Function
Also I have 3 classes of Type T, with all having different parametric constructor. It's important for me to have it generic as the Classes of type T might increase in future with less or more parameters.
I'm passing a type name and some parameters from C# code into a navigation framework written in VB. The navigation framework looks for a constructor on the type that matches the parameters passed in using Type.GetConstructor(Types()). The constructor that I'm looking for expects an array of integers Integer() in vb. But it gets an array of System.Int32. I've gone so far as to try this:
[Code]...
And the VB code still sees System.Int32 on the other end, which means that it doesn't find the constructor.
I want to make a generic EventArgs sub class that has a write-only property which, when updated by the code that is handling the event, will also update the byref parameter of the constructor of the class.
The code I have so far doesn't work. How do I get the property "Item" to update the "item" constructor parameter so I can retrieve the value that was set?
public class EventArgsSet<T> : EventArgs
{
public EventArgsSet(ref T item)
{
[Code].....
I'm trying to make this code with reflection since I want it to manage Technician and other types too.
[Code]....
I'm trying to change the reference of a variable passed from one form to another in the constructor of the recieveing form but after I've changed it the original reference still remains in the source form. Why is this and can I force it to accept the new reference?
View 12 RepliesHow 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 trying to call a method using Reflection on a method that has a STRING parameter.However a STRING does not have a parameterless constructor.So instead of something like.>>
Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1
[code].....
I have an abstract class which requires a delegate to function. I pass the delegate into the constructor. Now that I have a non default constructor I need to call the abstract class's constructors from the concrete class which means that I need to use MyBase.New(...). I have included a quick example below.
Public MustInherit Class BaseClass
Public Delegate Sub WorkMethod()
Private _Work As WorkMethod
[code]....
I have tried to do this but I keep getting the following error: "Implicit reference to object under construction is not valid when calling another constructor".Can I not do what I am trying to do above? I initially had the delegate setup in its own setter method. But then I am creating a deceptive API because it does require a point to a method to work properly.
what's the rationale behind this limitation: Constructor call is valid only as the first statement in an instance constructor i want to pass an argument to my constructor which validates this argument and calls mybase.new according to this argument but it doesn't let me
example:
Public Class prob
Inherits System.ApplicationException
Public Sub New(ByVal problem As String, ByRef inner_exception As Exception)
[code]....
What I wanted to do was, given the table name (as string), use reflection to instantiate the get method for specific fields (defined as properties with Get and Set methods.
Public Property VC60() As String
Get
Return _VC60
[code].....
I am preparing to deploy a web service that uses SqlConnection primarily as its means to get to the database, and I am adding some new methods that use a DataContext instead of thatand the default constructor and DBML file would use a connection string refering to my development machine (I believe...)
View 1 RepliesIs it possible to get a string form a table and executed at runtime using reflection?(.Amount > 1000) and ((.Total * 80%) >.Amount)� Amount and Total are Decimal properties of an existing class
View 4 RepliesI have buttons generated through code (dynamically). I have to associate an event (the same) to them. I use AddHandler button.click, AddressOf mysub.The issue is that mysub gets a string (mysub(string)), but AddressOf doesn't accept a parameter inside the routine. How can I do this? Using also an alternative to AddressOf.
EDIT:
Public Class Form1
...
Private Sub mysub(ByVal sender As Object, ByVal e As System.EventArgs, ByVal str As String)[code]......
Under component services, a COM+ component is used by the company, right-clicking it and choosing 'Activation' tab will show the 'constructor string' that is used for DB server connection by all applications. How can I access it the simplest way possible?
[Code]...
Dim PrinterIP as String
Dim Str as String
Dim objReg As New IWshRuntimeLibrary.WshShell
[Code]....
where i put the *'s i get the error "The parameter 'address' cannot be an empty string. Parameter name: address".
Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick
Dim mail As New MailMessage()
Dim SmtpServer As New SmtpClient
[code].....
I am not the one who developed this tool, it's the previous programmer and they gave the project to me to update it however, when I try to run the application in my local computer I am getting this error: Argument not specified for parameter 'XLSFile' of 'Public Sub New(XMLFile As String, XLSFile As String)'.
The error points to the code below in bold letter:
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Zym.ConnectionString = Web.Configuration.WebConfigurationManager.ConnectionStrings("cnworkload").ConnectionString
'Dim cn As System.Data.SqlClient.SqlConnection = New System.Data.SqlClient.SqlConnection(Zym.ConnectionString)
'Dim DA As New System.Data.SqlClient.SqlDataAdapter("SELECT * FROM SUMMARY_WORKLOAD", cn)
[code].....
I need to pass in parameters to my sub/function. When the parameter is passed, the value in the string, I would like to get the value evaluated and sent as:
Dim strParams As String = drRow(0)
' drRow is a row from DB Table. the value in drRow(0) =
' "@FromDate=""" & Now.AddDays(-10).ToShortDateString & """&@ToDate=""" &
[code].....
I get the following exception for the code shown below. The error occurs when i request access token.I downloaded the latest dll(2.3.1) from the twitterizer website.
{"Value cannot be null. Parameter name: String"}
Dim OAuthTokens As New OAuthTokens
Dim accessToken As New Twitterizer.OAuthTokenResponse
accessToken = OAuthUtility.GetAccessToken(ConsumerKey, ConsumerSecretkey, "oauth_token", "oauth_verifier")
I have a function that takes a String as a parameter And in it I have variables, so if I call it it's like
Dim Text As String = MyStringConverter("Hello Mr. " & Name & " " & Surname "!")
In my program i have it send an email and it send the email but after it sends i get this error "The parameter 'addresses' cannot be an empty string. Parameter name: addresses". I don't know why.
View 1 RepliesI'm calling unmanaged C++ Dll function from VB.Net project by usin dllimport attribute like this;
<DllImport("Injection.dll", CallingConvention:=CallingConvention.Cdecl)> _
Private Shared Sub Injector(ByRef Client As String, ByRef Dll As String)
End Sub
We have a legacy component that has been converted from VB6 to VB.Net.The VB component was called from an ASPX page using Request("param") to pass optional parameters to function calls. That means the value is null/nothing if the parameter is not present.The parameters were then added to an ADODB call of a store procedure using Parameters.Append.When used from VB6 missing, Request("param") values were coerced into empty strings when passed to the VB6 component. This meant that the ADODB call was satisfied (for required parameters).When the code was ported to VB.Net, the null Request("param") values are now passed as null values (VB nothing?) and Parameters.Append skips adding the value if it is nothing. This caused the stored procedure calls to break as a required param was missing.
If we change the component's function parameters to be optional and have paramname as string = "" defaults, will a null/nothing value be converted to an empty string, or is null/nothing treated differently to a parameter being simply missing?
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 have an update query and I'm receiving the error "Failed to convert parameter value from a String to a Int32."
I'm assuming this is because of a format issue... I'm using Text and Date formats. I've tried a few things but I'm not sure exactly what is causing this error.[code]...
i am trying to save data from unbound datagridview to sql database.Failed to convert parameter value from a String to a Int32. The following is my
Private Sub btnPlace_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPlace.Click
' Modify the following code to correctly connect to your SQL Server.
[code].....
When i hit the save button it gives me error"failed to convert parameter value from a string to decimal". [code]...
View 1 RepliesI'd like to see what is about to be sent to the SQL Server from my SqlCommand before SQLCmd.ExecuteNonQuery() runs.
I'm trying to debug because I am receiving the following error:
System.FormatException: Failed to convert parameter value from a String to a Int32.
Normally, I would use SQL Server Profiler to view what is being sent to SQL Server, but my statement is not making it that far. Is there a way to determine what it is trying to convert? I am having problems determining which parameter is causing the error.
how to implement Nullable Parameter of type string in vb.net
Function:
sub savedetail(byval name as string, byval age as integer)
if name isnot nothing then
some work
end if
[code]....