Take a look at the snippet above. On the third line, I'm trying to set a multidimensional array to the type that the current class is. How can I get the type of the class that I am currently in? I'm using VB.net so all .net examples are acceptable.
Dim a as Type=GetType(className) would gimme the type. But I have only the name of the class as string. I want something like GetType("class1") which would return the type.
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:
In VB.NET, if I create a class it is a reference-type. But, if that class it chock full of value type properties, how is this handled? If the class is instantied but never filled, I suspect a pointed for to the heap is allocated. But is more space allocated on the stack for all of it's value type properties?
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
I suspect I am being very silly here but I have the following setup
Class MustInherit myBaseClass 'some stuff End Class Class myInheritedClassA
[code]....
Running this results in the following error
Unhandled Exception: System.InvalidOperationException: There was an error generating the XML document. ---> System.InvalidOperationException:
[code]....
is there any way of 'Widening' the inherited class to the base class so this would work?
EDIT:regarding XmlInclude(typeof inheritedClass), currently this method could potentially return a number of types of inherited class (i.e myInheritedClassA and myInheritedClassB) is it case of simply having to add each of the inheritedTypes in this tag?
I am trying to open a project in Visual Studio. I have VB.NET and C# installed. When I open the solution, it says
"The project file D:MyProjectsComboSample.csproj can not be be opened." "The project type is not supported by current installation"
What do I need to install? C# is already there.
ComboSample.csproj
Microsoft Visual Studio Solution File, Format Version 10.00 # Visual Studio 2008 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ComboBoxSample1", "ComboBoxSample1ComboBoxSample1.csproj", "{6A1F1EE5-4AED-40E0-9517-3EAC47442628}" EndProject
I have an Account Class that is able to create notes(Class), however i am able to create the note object by itself which is not the desired outcome, i want only the account class to be able to create the note object. Another Example would be, an order item should not be created without an order class. But how do you enforce this in vb.net.
I have written a class to model an object in vb.net, using vs2008 and framework 2.0. I am serializing the class to an XML file for persistent storage. I do this with a method in the class like this:
Public Sub SaveAs(ByVal filename As String) Dim writer As New Xml.Serialization.XmlSerializer(GetType(MyNamespace.MyClass)) Dim file As New System.IO.StreamWriter(filename)
[code]....
I now want to do a similar thing but reading the class from file to the current instance, like this:
Public Sub New(ByVal filename As String) Dim reader = New Xml.Serialization.XmlSerializer(GetType(MyNamespace.MyClass)) Dim file = New System.IO.StreamReader(FullPath)
[code]....
However, I cannot assign anything to "Me". I've tried creating a temporary object to hold the file contents then copying each property and field over to the current instance.I iterated over the properties (using Reflection), but this soon gets messy, dealing with ReadOnly collection properties, for example. If I just copy each property manually I will have to remember to modify the procedure whenever I add a property in the future, so that sounds like a recipe for disaster.
I know that I could just use a separate function outside the class but many built-in .NET classes can instantiate themselves from file e.g. Dim bmp As New Bitmap(filename As String) and this seems very intuitive to me. how to load a class into the current instance in the Sub New procedure?
Traditionally, class/type name is literally spelled inside its definition.
Public Class MyCustomClass Public child As MyCustomClass Public Shared Function Clone(ByVal original As MyCustomClass) As MyCustomClass End Class
This is not a problem most of the time; C-languages even use class name as constructor methods' name. But consider a generic declaration:
Public Class MyListOfIntegers Inherits MyCustomList(Of Integer) End Class
[code]....
This scenario has 2 issues. The first one is that constructors are not inherited, and you have to provide pass-through wrappers in every derived class, — this is quiet dumb, but tolerable. The second issue is more severe: derived class inherits CloneMe() method which returns MyCustomList(Of Integer) , not MyListOfIntegers ! Every returned value must be manually DirectCast 'ed for further use with methods that expect MyListOfIntegers . This issue, together with the first one, renders inheritance of generic class almost useless.
So I need a "MyClass" alternative for static type-binding inside type definition. In case of generic type that is referencing other compound types, task could be accomplished by adding second parameter to type section:
Public Class MyCustomList(Of T, TList) ... Public Function CloneMe() As TList
[code]....
But since we must reference our own type, it would create an infinite recursive loop of additional typeparamlist arguments. How can this be resolved, aside of creating separate classes without generics?
CREATE TABLE [LogLevel] ( [Id] int primary key ,[Name] nvarchar(50) not null
[code]....
After creating a fresh endity model, I add the two tables above. When I try to build I get the following errors...
Type argument 'Inxsol.CommandPlan.Data.Model.Log.LogLevel' does not satisfy the 'Class' constraint for type parameter 'TEntity'. Value of type 'System.Data.Objects.DataClasses.EntityReference(Of Inxsol.CommandPlan.Data.Model.LogLevel)' cannot be converted to 'System.Data.Objects.DataClasses.EntityReference(Of Inxsol.CommandPlan.Data.Model.Log.LogLevel)'.
Code: Dim dom As New DOMDocument30 dom.async = False dom.Load(serverAddress & "/App/filelist.jsp?type=content") For i = 0 To dom.childNodes.item(1).childNodes.length - 1 downloadfile(dom.childNodes.item(i), mcount, currentpath) Next
The above code is activated upon clicking of a button. i have the server address declared. and using the domdoc to load the jsp file to generate the xml data. and using for loop, i call the download file function which accepts the following parameters
Code:Public Sub downloadfile(ByVal domdoc As Xml.XmlNode, ByVal totalcount As Integer, ByVal currentpath As String)
The totalcount and currentpath work fine, but when i pass in the dom.childNodes.item(i) , error pops up.
--------------------error message------------------------------------------Unable to cast COM object of type 'System.__ComObject' to class type 'System.Xml.XmlNode'. 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.-------------------------------------------------------------------------------
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.
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 my best now to develop a way or a function which can automatically cast a variable from type : OBJECT to instance of my own class based on some parameter.
I tried the following but it's not working fine
it show an exception ("
Object reference not set to an instance of an object.") on line :
OT = obj.GetType Imports System.Reflection Public Class APP_USER
At the moment I'm in the process of building a class that can handle more advanced mathematical equations and processes. Essentially my end goal is to to have my class capable of processing anything you'd learn in Elementary Algebra through College Algebra. So far I am able to multiply monomials and order polynomials.. However for the most part the equations in questioned being processed have to be in correct form. IE Point-Slope Form, Y-Intercept Form, etc etc. I'm just curious as to how I can go about "validating an equation type by it's current form".
How can I get all the properties of a class that implement a specific base class or interface? I have a properties class that contains several other property classes. Some, not all, of these classes implement an interface. I would like to know if it's possible to iterate over all properties of parent class for child-classes that implement the target interface. It sounds like a job for reflection? I'm just not sure how. Can it be done via the "PropertyInfo" object?
I have the following sample code in a VB.NET console application. It compiles and works, but feels like a hack. Is there a way to define EmptyChild so that it inherits from Intermediate(Of T As Class) without using the dummy EmptyClass?
Module Module1 Sub Main() Dim Child1 = New RealChild()[code].....
The other way to do this would be to move the generic code out of the Base class and then create 2 Intermediate classes like this [code]...
Then RealChild would inherit from the generic Intermediate and EmptyChild would inherit from the non-generic Intermediate. My problem with that solution is that the Base class is in a separate assembly and I need to keep the code that handles the generic type in that assembly. And there is functionality in the Intermediate class that does not belong in the assembly with the Base class.
I am trying to check whether an object is of a particular class type, or if it derives from a particular class type. I've tried to do this muliple ways. But have not had much success. I am using VB.NET.
Here is the code that am using:
If Me.Page.GetType() Is GetType(AALASWebsite.ContentPage) Then hlPrintPage.Visible = False End If
I have a "generic" Tag class which holds an ItemValue, which at this time is declared as Object. The ItemValue could be one of several datatypes; String, Boolean, Integer, etc. Is there a way to create a class property to identify which data type the Tag is?
I've tried this but it's not working;
Public Property DataType As Type Get Return m_DataType
I create a object type entity in the main function and would like to pass it to a separate class, do some calculation, and then pass the result back to the main function. But I keep getting errors, can someone point me where I did wrong? It's in windows application[code]...
im making a function that disables controls except for a type of control i want to specify. how would I make the header of this procedure is my procedure should capture a control and a object of any type If I would call modUtilities.DisableControls(Panel_OwnerInfo, CheckBox_HasCell) is should disable all the controls inside Panel_OwnerInfo except for the CheckBox_HasCell Now I've done the disabling thing, but how would I specify the procedure parameter to recieve a class type?
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.