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 have a parent class that is also a factory. For example:
Public Class Factory
Public Function clone() as Factory
' Some logic here
[code].....
I have had several occasions recently to access a specific class several times over a relatively small time frame.So I've been storing the value of the class in Session and trying to access it on page load, if it's not available creating a new instance and storing that in session.
So instead of constantly replicating the same code for different classes on different pages I'm trying to create an extension method to do this for me.
[Code]...
I'm stuck on what to do when I make my new instance of my class (it would have to have a New() sub)
I'm not sure where to go from here... or even if this is the best way to do it.
I have an open source project I converted to vb.net. I solved all the errors, except for one. This is the C# line
[Code]....
System.String is a class type, but why we can use it without instantiate it with New keyword?
For example:
Dim CommandLineParameters As String = Microsoft.VisualBasic.Interaction.Command
No new keyword being used at all?
.NET I want to clone a value type's fields. How can i set a field value on a value type using reflection (or something else dynamically)?
This works for reference types but not for value types. I understand why but I don't know an alternative.
shared function clone(of t)(original as t) as t
dim cloned as t
'if class then execute parameterless constructor
[Code]....
I am trying to write a function that has an object parameter. That object will always be an BindingList. That BindingList will be of some unknown (at design Time) class. I think I've figured out how to get the type of the collection object, but now here the tricky part. I'm trying to create a function that can handle any type of collection and be able to return an item from that collection. I need to create a new object of that type and return it from the function. [Code]
View 1 RepliesI'm trying to use reflection to get the instance of a class in vb.net. I have a class 'A' in my web project and to test it, i create a new aspx page and try to write the following:
Dim t as Type = Type.GetType("A")
This returns "Nothing". But if i do this:
Dim inst as A = new A()
Dim t as Type = inst.GetType()
t's type is "A"
So how come i can't get the type with GetType even if the name is exactly the same? It does works for things like System.Math though
I'm trying to use reflection to populate the properties of an array of a child property... not sure that's clear, so it's probably best explained in code:
Parent Class:
Public Class parent
Private _child As childObject()
Public Property child As childObject()
Get
Return _child
[Code] .....
The issue is now trying to get that array assigned to the parent object (using reflection). It shouldn't be difficult, but I think the problem comes because I don't necessarily know the parent/child types. I'm using reflection to determine which parent/child is being passed in. The parent always has only one property, which is an array of the child object. When I try assigning the child array to the parent object, I get a invalid cast exception saying it can't convert Object[] to.
Basically, what I have now is:
Dim PropChildInfo As PropertyInfo() = ResponseObject.GetType().GetProperties()
For Each PropItem As PropertyInfo In PropChildInfo
PropItem.SetValue(ResponseObject, ResponseChildren, Nothing)
Next
ResponseObject is an instance of the parent Class, and ResponseChildren is an array of the childObject Class.
This fails with:
Object of type 'System.Object[]' cannot be converted to type 'childObject[]'.
I am trying to create an Excel file using reflection. The reason, the application will be running on many machines some of which may or not have excel installed. I decided to embed the "Microsoft.Office.Interop.Excel.dll" and via reflection generated the excel spreadsheet. The code I am trying to resemble is:
[Code]....
Is there a way for a property to access its own name and type at runtime using reflection? I want to access this info without hard coding the name or index of the property in the class.
Simple Example Code:
Private ReadOnly Property MyProperyName() As String
Get
Console.WriteLine((Get Current Property Info).Type.ToString)
Console.WriteLine((Get Current Property Info).Name)
[code]....
I've got a set of static "enumeration" classes that I'm using to hold meaningful variable names to represent meaningless code values I receive on an input file. Here's an example of one.
Public Class ReasonCodeValue
Private Sub New()
End Sub
[code].....
I 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 trying to create an object Of a specific type. I've got the following code, but it fails because it can't cast the new table object to the one that is already defined. I need table to start of an IEnumerable type so I can't declare is an object.
Public sub getTable(ByVal t as Type)
Dim table As Table(Of Object)
Dim tableType As Type = GetType(Table(Of )).MakeGenericType(t)
[code]....
is there a way of changing a variable type at runtime?
I'm attempting to dynamically register entities and configurations with a context (ef4 code-only). I would normally do:
Private Shared Sub ConfigureDatabase(ByRef Builder As ContextBuilder(Of ContextExtension))
'Load configurations for each of the tables (Entity sets) in our database...
ConfigureEntity(Builder, New ContactConfig)
End Sub
Private Shared Sub ConfigureEntity(Of T)(ByRef Builder As ContextBuilder(Of ContextExtension), ByVal config As EntityConfiguration(Of T), ByVal setName As String)
'Register the entity configuration with the builder
Builder.Configurations.Add(config)
'Register the entity set name with the builder
Builder.RegisterSet(Of T)(setName)
End Sub
Where ContactConfig is a class which inherits EntityConfiguration(Of Contact) and Contact is a class which implements an interface IEntity (IEntity is common to all entities). So... I need to search a namespace (say Project.DB.Client) for all signatures that match:
EntityConfiguration(Of <Class which implements IEntity>)
How can I achieve this?
I know its unlikely but I was wondering if there is any way to get the comments (i.e. the bits after the ''') of a class or property..? I have managed to get a list of properties of a class using the PropertyInfo class but I cant find a way to get the comments / description.. I need it for a guide I am writing for the administrators of my site - it would be great if it could automatically update if new properties are added, so there is no need to worry about updating it in the future too much.
View 5 Replieshow to create an instance of a class then add properties to the class, set those properties, then read them later. I don't have any code as i don't even know how to start going about this. C# or VB is fine.
My system has a dynamic form creator. one of my associates requires that the form data be accessible via web service. My idea was to create a class (based on the dynamic form) add properties to the class (based on the forms fields) set those properties (based on the values input for those fields) then return the class in the web service.
additionally, the web service will be able to set the properties in the class and eventually commit those changes to the db.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Dim resources As
System.ComponentModel.ComponentResourceManager = New System.ComponentModel.ComponentResourceManager(GetType(_Class))
[code]....
How can I reach that sqlparameter collection via fieldinfo or other related classes in >NET Reflection?
Code snippet:
Dim target As Object
' target gets properly set to something of the desired type
Dim field As FieldInfo = target.GetType.GetField("fieldName", _
BindingFlags.Instance Or BindingFlags.Public Or BindingFlags.NonPublic)
field.SetValue(target,newValue)
This snippet works perfectly IF target is set to an instance of a CLASS.However, if target is set to an instance of a STRUCTURE, the code does not actually change the value of the field. No error, but the value remains unchanged.And, oddly, if I'm stepping through code, watch the SetValue fail to do anything, and immediately go to the Immediate window and type exactly the same SetValue operation, that works.
Edit:
Per request from Jon Skeet, actual code:
Private Shared Function XmlDeserializeObject(ByVal objectType As Type, _
ByVal deserializedID As String) As Object[code].....
I'm trying to check if a variable has been defined as a nullable Guid. eg.
Dim myGuid As Nullable(Of Guid) or Dim myGuid As Guid?
It seems doing a myGuid.GetType returns the underlying type, that is type Guid, not Guid?. So testing myGuid.GetType Is GetType(Guid?) always returns False.How do I find out if myGuid is a nullable type?
Ed: I can do the following, which correctly returns True for "Guid?" and False for "Guid":
Not Nullable.GetUnderlyingType(GetType(Guid?)) Is Nothing
The problem is that I don't know how to retrieve the nullable type from the variable itself, in order to test it. I've only been able to get the underlying (non-nullable) system type.
I've written a db helper function. I pass it an object comprised of public members, representing the row data of a table. The members are the table columns.Using reflection, I loop through these public members to create an INSERT statement for a command object and populate its parameters with the values in those members. So far so good.But now there's a table which has a uniqueidentifier column which I must not populate from the row object, as it defaults to "NEWID()" (using SQL Server 2008). Instead of skipping all Guid columns, which would be easy, I only want to skip ones defined in the row data class as "Guid" (non-nullable).Basically, I'm using the Guid? (Nullable) type to indicate it's ok to populate that uniqueidentifier column with data. If it's non-nullable, that tells me to skip it because the column has a NEWID() default value.
I want to retrieve private (implementation and other) methods of a class which implements an interface and also is derived from (inherits) a base class.How can I achieve this using reflection?This is wat m tryin to do. I need to view these private methods and their contents, I don't want to invoke them.
Dim assembly As System.Reflection.Assembly
Dim assemblyName As String assemblyName = System.IO.Path.GetFullPath("xyz.dll")
assembly = System.Reflection.Assembly.LoadFile(assemblyName)
assembly.GetType("myClass").Getmethods(Bindings.NonPublic)
assembly.GetType("myClass").GetMethods(BindingFlags.NonPublic) isn't working
I'm making a little program in where i'm trying to invoke a method from a class dynamically with so called Reflection.The class I'm trying to call is called ContactList and i try to invoke the method in this class called count. The assembly itself is called Contact.ExeNow I have the following code:
Public Function InvokeContacts() As Integer
Dim ContactsAssembly As Assembly = Assembly.LoadFrom("Contacts.exe")
Dim Mycontactlist As Type = ContactsAssembly.GetType("ContactList")
[code]....
I am currently using reflection to retrieve all properties of a class. I return a collection of PropertyInfo objects and all is working fine.
My problem is, I want to check if a property has been defined in a base class implementation and is therefore inherited in the current class.
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 know that the MenuItem class contains an internal class named MenuItemData, which contains itself an internal member named onDrawItem. Given a MenuItem, I want to retrieve the object corresponding to the member onDrawItem. But all I manage to do is to get the FieldInfo, not the object itself.
Here is my code:
Dim obj As Object
Dim fi As FieldInfo
Dim item as System.Windows.Forms.MenuItem
Dim mType As System.Type
[Code] .....
When reaching the last line, I get an error saying something like that (it's traduced):
The field 'onDrawItem' défined in type 'System.Windows.Forms.MenuItem+MenuItemData' is not a field of the target object of type 'System.Windows.Forms.MenuItem. I don't know what object to pass to the GetValue function on the last line. My goal is to remove the base eventHandler of the menuItem, named DrawItem. See this post and the function RemoveClickEventin the accepted answer for a better understanding.
I am working on a project where my class has to execute VB code provided by the user, to make it simple I am trying to recreate my own eval function, I am using the following code I found on the web to do this task.
Imports Microsoft.VisualBasic
Imports System
Imports System.Text
Imports System.CodeDom.Compiler
Imports System.Reflection
[Code] .....
The problem with code is that it can't access any variables or there values, so I have decided to get the variable names, there values types and there types dynamically and recreate them in the class that is being created dynamically. Any way to get the variable names there types and values in the current class or method, so that I can recreate them, and execute the user passed code, the user knows what variables are in the current class or method and there datatypes but he don't know there values as they may have changed, so he can't initialize them. Is there a way to do this, this code will be called in an asp.net page on page_load event, the code passed by the user is stored in the variable vbCode that is passed as a parameter.
I'm trying to make a very simple audio tag editor. The idea is that the user can select as many audio files as he likes from a ListView, and a PropertyGrid will then display their tags + their values.When multiple files are selected, I want the property grid to display the values of the tags that all files have in common, and display empty values for tags that the files do not have in common.As an example, look at the properties list in your Visual Studio IDE when you select multiple controls (of the same type for this matter). Select a few Button controls, for example, and notice that the properties whose values are the same (often things like Font, ForeColor, etc) are displayed. Also notice that the values for properties that are not the same (Text, Name, etc) are empty.
View 17 RepliesI have a solution with two projects within:
Company.Project.vbproj
Company.Project.Tests.vbproj
Within the Company.Project.vbproj assembly, I have a class FriendClass.vb which scope is Friend (internal in C#).Now I wish to test this FriendClass.vb from within the Company.Project.Tests.vbproj assembly. I know about the InternalsVisibleToAttribute, but that is not an option in Visual Basic .NET 2.0, as it is only available with C#, in .NET 2.0 (see here).I would like to create myself a proxy class using this internal FriendClass from within my testing assembly, so that I could instantiate it and do the testings accordingly.
I am just curious, if there is some way to attach handler to my derived classes base event, if I know EventInfo and I have Delegate to handler function. I have tried MyEvent.AddHandler(CType(Me, BaseClassType), MyDelegate) already, but no positive result at all. Consider being in need of attaching handler to custom event at runtime, while derived class possibly shadows this event.
View 2 RepliesIs 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 Replies