I am declaring an IList:
Dim OrigVendors as IList
OrigVendors = new List( of IVendors)
I populate the OrigVendors variable and what I want to do is find all the objects that have the ID I am looking for. Then I need to update a property on that object for only the ones found. Is this do able with an IList or do I need to use some other type of collection? I am using VB.net.
I am constantly receiving back objects and it would be very useful be able to print out all of their properties. Is there a way in VB to get all the properties of an object and print them out (to console)?
View 3 RepliesI'm trying to use a variable that is simply a list of a list of strings.I've declared it as follows:
Dim iRows As New List(Of List(Of String))
Then I'm trying to pass it as a parameter to another method and I've defined the method as follows:
Public Sub Import(ByVal Rows As IList(Of IList(Of String)))
For Each Row As IList(Of String) In Rows
ImportRow(Row)[code]....
Unfortunately, when I try to run that code I get the following error where it tries to pass my variable to my method.
System.InvalidCastException was unhandled by user code
Message="Unable to cast object of type 'System.Collections.Generic.List1[System.Collections.Generic.List1[System.String]]' to type 'System.Collections.Generic.IList1[System.Collections.Generic.IList1[System.String]]'."
When I change the method definition to use the types rather than the interfaces as follows, it works.
Public Sub Import(ByVal Rows As List(Of List(Of String)))
For Each Row As IList(Of String) In Rows
ImportRow(Row)[code]....
So, is it not possible to use generics with interfaces in this way? It works fine as long as I'm not nesting them.
I am using a loop to update properties of each object of a set of custom objects. The routine knows which controls to update because the controls value is not empty, I don't want the routine setting the corresponding properties to nothing when the control is empty. Now I know how to do this perfectly fine with IF statements such as:
CODE:
But this feels really redundant doing that same IF block over and over for each property/control combination, I thought about creating a separate routine that takes the control as an argument and does all the repetitive IF blocks but I don't know how I could also pass an object property to tell the routine to update that particular property.
Okay, so I have a Generic IList of custom objects that I want to use as a datasource for a repeater.
Dim productRows As IList(Of MyCustomObject)()
'fill list with data
rptResults.DataSource = productRows
[code]......
I'm new to generics and am having some issues when using with interfaces.I'm developing with VS2008 - .NET 3.5 Ultimately, I'd like to create an interface that inherits the IList(Of T) interface and add a function definition to the derived interface that adds a new element of type T to the list and returns the index of the newly added item.
I have everything figured out but am stuck on a casting issue. If I execute the following line of code at runtime:CType(New clsObjectFactoryList(Of clsIDNamePair), ifObjectFactoryList(Of ifIDNamePair))
I am somewhat new to object oriented programming and am attempting to flatten a Linq object hierarchy by using a shim class.how to initalize a derived class with property values from a base class?I have two objects, a base object with about 100 properties, and a derived object which inherits from the base object and adds a few additional properties beyond those of the base object. My simple constructor creates the derived object, but I am looking for a way to initialize the derived object properties with values from the base object.Right now I am using reflection to iterate over the properties individually and I suspect there may be a better way. The following example shows my shim class constructor for the derived class, and two properties:
newProperty1 - a new string property of the derived class
flattenedProperty2 - a new string property of the derived class, copied from a 2nd-level object of the base class
Code example:
Public Class derivedObj
Inherits baseObj
Private _newProperty1 As String[code].......
Is this the correct constructor approach to flatten the object hierarchy using a shim class? My second question relates to initialization of properties in the derived class. The constructor above creates the derived object, but what is the best way to initialize the derived object properties with values from the base object? The following code uses reflection to iterate over the properties individually, but I suspect there may be a better way.
Code example:
' property names are in the string array fieldNames
'baseObjQuery is an ienumerable of baseObj
'derivedObjList is a list of derivedObj[code].....
Is there a simple way to initialize values for the properties in the derived object based upon the values of the common properties in the base object?
I was asked to develop a simple application to handle car inventory. Each car has a LOT of properties (about 130, like license plate number, type, was it serviced, etc.). Some of these properties are represented by bit data type in a database some are varchar.
The problem is that I need to provide search functionality for any of all these properties and any combination of them. This results in a search form with about 130 controls. I certainly do not want to put the SQL query together manually by checking the state of each and every control. To propagate the problem further I need to be able to search for partial strings as well (i.e. if the user enters "porsc" into the car brand field then all Porsches should be found).
I am trying to implement image caching for a web application and I found some code on the Internet that implements an HttpHandler that does this. The code was in C# and since my web app is written in VB, I decided to convert the code to VB. I managed to convert everything except the following code (in bold):
public class FileExtensionCollection : ConfigurationElementCollection
{
public override ConfigurationElementCollectionType CollectionType
{
[CODE]...
From what I can understand, the two properties above provide a way to access the FileExtension collection either using an integer or a string index. My problem is that I do not know how to convert this in VB.
I want to build a MVC helper function for which I pass a Entity Framework object and have it build a select. Generally speaking I tried something like this:
Public Function RenderSelect(ByVal helper As HtmlHelper, ByVal sSelectName As String, ByVal aItmes As Array, Optional ByVal sTitleKeyName As String = "name", Optional ByVal sValueKeyName As String = "id") As String
' open select
[Code].....
However, it isn't working. It would be great to have a way to do this and pass the current entity object.
Dynamic Object Properties in a MVC Helper on a Entity Framework object
View 1 RepliesI'm having trouble porting some .NET2-era C# to .NET2-era VB.NET. Specifically, I am trying to define an interface that an ASP.NET user control will implement.(For background, I am trying to re-implement Phil Haack's Model-View-Presenter example from several years ago: http://haacked.com/archive/2006/08/09/ASP.NETSupervisingControllerModelViewPresenterFromSchematicToUnitTestsToCode.aspx)
The C# interface I'm working from defines properties and events (IsPostBack, Load) that are already implemented by the base control.However, VB.NET is forcing me to explicitly implement these properties/events in the user control (Public Property IsPostBack() As Boolean Implements IView.IsPostBack...). I'd like to just define these in the interface and not have to do anything special in the code-behind of the implementing user control.I'm assuming that I can do this in VB.NET, I just don't know how. I've spent all sorts of time googling/bing-ing, and haven't come up with the answer.
I'd like to have something like:
[Code]...
As an update rolls out in one of my applications, I would like to implement an update checker. My situation is that, when a user clicks a drop down item called "Check for Updates", I want it to check for updates. My application is simple, I don't publish. I upload to a mediafire and put the download link to my blog. The only file I need in my application has always been the .exe file of the application itself. My question is, what is the simplest and best way to implement a update checker?
Example:User is using v1.1 and checks for updates. He clicks the "check for updates" and a popup shows up with yes, update available and is a msgbox yes or no. Yes, would allow the user to download the update. No, closes the msgbox. If there is no update available, then a msgbox shows "You have the current version". If the user is offline or cannot check I would like to have an exception to show why he cannot check.Basically, working with the download aspect and everything else is familiar to me but I have no idea how I can check.
Try
My.Computer.Network.DownloadFile("downloadurl", "downloadlocation.fileextension")
Catch ex As Exception
MsgBox(ex.Message)
End Try
how do we implement Finalize to remove an object?i tried this:
Public Sub kill()
Me.Finalize()
End Sub
then this:
Dim g = New Test
g.kill()
MsgBox(g.ToString)
weird the object still exists, i don't get a NullReferencePointer exception
in my datagridview, i have a column where, depending on values in other columns, I declare a new DataGridViewImageCell, set the image and then attatch it to the grid (brief example below):
Dim cell As DataGridViewCell = New DataGridViewImageCell
Dim img As Image = imgList.Images("comments")
Dim i as Col = 1
cell.Value = img
grdHeldOrders(column.Index, i) = cell
When i click on the column header in question to sort, I get the exception "At least one object must implement IComparible". I kind of guess this because certain cells are different types but I'm not sure how to get around the problem and where to implement IComparible. Does anybody have any examples?
I'm binding a DataGridView to a BindingSource to a LINQ IEnumerable, I found that the BindingSource.Find method throws an exception because .Find isn't implemented in IEnumerable (and the BindingSource just passes the call to it's DataSource). I need to use BindingSource.Find to select/highlight a particular row in the DataGridView.
Is there a feasable way to extend my DataContext to support this behavior w/o breaking anything else? I expected to find the code out there already, but I've searched exaustively with no luck.Without it, I cannot "move" the BindingSource using .Position and that's a pretty common use of the BindingSource I think.
I've now properly started implementing OO into my system (which I probably should have done from the start) but I just want to clear some best practices.So let's say I have a class called Job which contains information such as Description, Project Manager (Employee class), Value etc. at the moment, if I initialise the Job class it will initialise all the information held within it, even if I only want the job description. Is it best practice to do this or is it better to implement the class and access the database for values as and when they're needed? Or is it just better in those cases to just access the database directly?
View 1 RepliesMy.settings Properties are Read-Only. How can these be updated in program code?
View 4 RepliesI'm wanting to dynamically create some controls relative to controls already placed on the forum at design stage, how do I find the locations of the controls that are already placed?For example, I have a label called lblDateTime, its location is (13, 167) and its size is (65, 13).In my code, I want to place a new label below this label.I've tried to set the location and size properties of the new label using the location and size properties of lblDateTime.Size works, no problem, but the location of lblDateTime always returns as 0,0.[code]I want to set lblMessage DateTime. Location to (13, 180), but I'm actually setting it to (0, 13)What confuses me most is that Me.lblDateTime.Size is returning the correct values, so it's not like my code isn't finding the control.
View 5 RepliesAt first I was using this as an extension method to update my detached entities...
Public Sub AttachUpdated(ByVal obj As ObjectContext, ByVal objectDetached As EntityObject)
If objectDetached.EntityState = EntityState.Detached Then
Dim original As Object = Nothing
[code]....
Everything has been working great until I had to update non-scalar properties. Correct me if I am wrong but that is because "ApplyCurrentValues" only supports scalars. To get around this I was just saving the FK_ID field instead of the entity object relation. Now I am faced with a many to many relationship so its not that simple. I would like to do something like this...
Dim Resource = RelatedResource.GetByID(item.Value)
Condition.RelatedResources.Add(Resource)
But when I call SaveChanges the added Resources aren't saved. I started to play around with self-tracking entities but it seems they cannot be serialized to ViewState and this is a requirement for me.how to either save my many to many relationships or serialize self-tracking entities?
i'm currently trying to test a program at home that i've written for an assignment at university. At the university they have a dedicated SQL server that i can connect to fine enough but to test and debug at home i have installed MySQL 5.1.
I now have trouble connectioning to MySQL the error message i get points towards that my program is acutally looking for an instace of MS SQL server and i don't know where to change this.
I have downloaded and installed "MySQL ODBC Driver-MyODBC 3.51" which some people have suggested corrects the problem, unfortunatly this doesn't work.
The current code i have is:
Dim strConnBuild As New SqlConnectionStringBuilder
With strConnBuild
.DataSource = "localhost"
.InitialCatalog = "northwind"
[code]....
I can't find any properties of the SqlConnectionStringBuilder that indicate what instance and protocalls it should use.
Is there a method to find the property names for an activeX object via an interface? The property names I am searching for are the ones used in the OBJECT / param HTML tag. I have been searching through the documentation and found the IPropertyBag interface but when I call QueryInterface I receive the E_NOINTERFACE error.
View 4 RepliesI 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 am trying to figure out how to add my own properties to an object. i am trying to make my own rpg game and i want to be able to refer to a integer property like so: strengthstat = bronzelongsword.attackstrength. of course strength stat being an integer vairable that would equal to the property attackstrength that belongs to the bronze longsword.
View 14 Repliesi am trying to add a text file in Debug folder. But when i go to project tab to add a new item, there is no option to add a new item? What part of the setting needs to be changed? Using Visual basicExpress 2010.
View 1 RepliesI'm debuging an complex calculation object in my project, and I'd like to show its various and many properties in a textbox, to make my tests easier.
Can I do something like
for each p as someKindOfProperty in MyObject1
debug.print(p.name & " - " & debug.print p.value)
textbox1.text = textbox1.text & vbcrlf & p.name & " - " & p.value
next
I need to get all the object properties of a web browser. in this web page how do i retireve all the proeprties, like the text box name, html id, button name and so on.Also help me with retrieveing all the html ids of the browser. the html ids could be seen in the source page. but how do i get those ids.
View 8 RepliesI have a property grid and I want to be able to set the selectedobject to a class. The class contains properties. This is what I have, but it 'OtherFiles' is not an object.
pgProperties.SelectedObject(OtherFiles)
How do you create a class as an object. In VB.NET 2008 please. C# is ok.
I have a form that has 100 text boxes with 100 coinciding labels. I want them hidden until another function populates the text boxes with data gathered elsewhere. The data could be between 1 and 100.
I would like one loop where I can assign the data to the correct text box, set it visible and set the label visible. I can not figure out how to do this in VB, or know if it is even possible.
Here is an example of what I would like to do
Dim i As Long = 1
Dim textbox As String = "textbox"
[code]....
I would also like to do this to hide all the items on the form in the on load event.