I want to be able to get an instance of a class based on two fields in that class. I was hoping to use something like a dictionary, because I thought indexing would be the best for performance. Should I just use LINQ or go back to a strongly typed dataset? Here's an example of what I'm trying to do[code]...
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VB.NET .NET 3.5 I have an aggregate class called Package as part of a shipping system. Package contains another class, BoxType . BoxType contains information about the box used to ship the package, such as length, width, etc. of the Box.
Package has a method called GetShippingRates. This method calls a separate helper class, ShipRater, and passes the Package itself as an argument. ShipRater examines the Package as well as the BoxType, and returns a list of possible shipping rates/methods.
What I would like to do is construct an Interface, IRateable, that would be supplied to the helper class ShipRater. So instead of:
[Code]...
However, ShipRater requires information from both the Package and its aggregate, BoxType. If I write an interface IRateable, then how can I use the BoxType properties to implement part of the Interface?
I'm looking for a tutorial on how to Adding a list(of Class) or Collection as another Class's Property.What I am after is something like the Columns Collection for the DatagridView control.I would like to add Items in the graphics screen. Where the item list is displayed in the left panel and the selected Item properties are displayed in the right panel.
View 4 Replies[code]The reason that this is a problem is that this is a collection of EventBase objects, but I'm trying to populate it with child classes instead. For example, I might have a JumpEvent class that inherits EventBase, and this is being put into the EventBaseCollection. That means that value.GetType() returns the type of JumpEvent, which as you might guess does not equal the type of EventBase.The goal of course is to simply loop through all of the various events without having to know anything about the sub-classes. Is there a way to determine the type of the base class so that the OnValidate call will work? Or is this just the wrong way to go about it altogether?
View 2 RepliesI seem to have problem with passing a collection/sorted list/ list of strings from one class to another.I am using property procedure to pass it, however nothing is sent to another class. There isn't any error messages either.[code]
View 3 RepliesThe following code creates a Collection where every Item is assigned a value equal to the last item added. At the end of adding for example seven items all the entries are identical to the last one added, although each has the correct key
The parameter passed to the function - aCOA() - is a comma delimited string of three strings.
The code is as follows
Public Function myCOA(ByVal aCOA() As String)
Dim thisCOA As New Collection
Dim keyCOA As String
[Code]....
Is this a bug in the code or in the Collection Class. I have traced the operation of the code and all seems OK until the second entry is added at which time the first entry Item get the same value as the second entry Item and so on.
I have worked some with classes and collections in the past but seek some direction before I start on this project as to the best method to use.I will be reading 20,000 or so lines from a text file. partno, desc and loc Each will contain 3 elements to be collected and stored temporarily.There are 2 results that I desire that relates to selling of products
First Result: Sorted list of most used partno, desc
2,234 partno (most sold)
1,345 partno (2nd most popular)
etc.
2nd Result: Sorted list by specific loc., partno, desc
loc. 45 - 234ea partno, desc
loc. 45 - 143ea partno, desc
Maybe end up with the top 500 selling products in the list. This data will then be added to a dataviewgrid for printing and then deleted.So, to temporary store and sort should I use some type of collection or classes? I know how to fight my way to either but which would be the best method?
I have some nested objects arranged like this:
Process
Persons
Workflows
Tasks
So you have one Process. Then multiple Persons can be added to and multiple WorkFlows can be added Process as well. Multiple Tasks can be added to each WorkFlow but I need a way to tie which Person is doing each task. I basically need a way that for each Person added to the Process it, in it's constructor, assigns a Person.ID property that can then be assigned into each Task's PersonID property...
Dim myProcess as New Process()
Dim myPerson as New Process.Person()
myProcess.AddPerson(myPerson)
[code]....
I converted a project from 2008 to 2010 to be able to use the TPL.I've updated the compile target to .NET 4. Everything seems good, including the .NET 4 specific TPL stuff...except that:[code]
View 7 RepliesThought I had got this sorted earlier but unfortunately not. A property in a class is a collection of objects.
[Code]...
I decided to go back to the VB6 book, "Learn to Program Visual Basic Objects", so I can code it in VB2010. This has been a great learning experience. However I've run into a problem. I'm getting an error with a For....Each loop for a collection class. The error message states, Expression is of type 'China.Order', which is not a collection type." From what I've deduced the problem deals with an enumerator. I could be wrong.
View 2 RepliesI'm working on a small project and got into some troubles trying to keep it OOP.I have a global variable:
Public Stations As New Microsoft.VisualBasic.Collection()
And 2 classess: Station & Unit:
Public Class Station
[code].....
I'm having problems doing a sort of a custom collection. The collection is Device Classes which is a collection of Device Class. My sort does not produce an error but the treeview control shows nothing. I am not sure what I am missing. I'm guessing just a simple sort won't work here but I don't know what I'm missing in my code. Here's the code that creates the collection
[Code]...
Simply sorting the treeview will not work because it throws off the display of related info for a given device in listview controls. The collection itself needs to be sorted before the data is added to the treeview.
I have a custom class that has one property as a collection.For some reason XmlSerializer doesnt like the class having a collection property and the Serialize Fails!If I remove the collection property it works! Is there a special way of getting the collection in the class to work?
View 1 RepliesI'm trying to create a collection of variable binding in a class.It is intended to look something like this:
Dim x as integer, s as string
Dim c as new VBindClass
x = 1
s = "Hello"
[code]....
Is there some function that allow us to retrieve a unique ID for a given variable and also get/set based on variable?
Update:At last, I've managed to found the answer. Here's the code:
Dim gh As Runtime.InteropServices.GCHandle = Runtime.InteropServices.GCHandle.Alloc(obj)
Return Runtime.InteropServices.GCHandle.ToIntPtr(gh).ToInt64
I have class called GroupSelect and made a collection List(Of GroupSelect)().[code]...
View 1 RepliesI am moving from VB to C#. I am trying to loop through a collection class which is a collection of data classes but I can't seem to get the actual values out of the data class properties(find the correct code to do so). I have a method that loops through the collection class(Contacts) and saves each record(Contact). I am using reflection because my method will not know if it is Contacts class or a Customer class and so forth. Here is my code in VB(watered down)
Public Function SaveCollection(ByVal objCollection as Object, ByVal TableName as string, ByVal spSave as string)
Dim objClass as Object
[Code]....
The C# code keeps returning null. In my locals window I can see the proprties on the class on objClass and the value of the propery but I can seem to figure out how to access it through code. I used the DictionaryBase because that seems to closely match would I need to do. My data class(Contact) has a bunch or properties that match the field names in the database of the Contact Table. After I get the propInfo variable set I then set up my SQLParameter with the fieldname, datatype etc and then set the value to the propInfo.value.
Is there a way to change a base class type by Overrides or Shadows, or other meen?[code]...
In this example there is MyBaseClasswitch is the base Class, then ClassB that Inherits from MyBaseClass, and In ClassB I try to overrides the base property "MyColl" to change is type to a enum.
But it do not work, telling me that the base collection cannot convert to eCarBrand, blah blah blah
Is there other way to change base class type or other approach that a could use?
How to create collection class and add list of items to collection class that stores list of items?
View 3 RepliesIs there a way to have a class collection of inherited types be initialized? For example, here is my code:
Public Class CamryCar
Property Name As String = "Camry"
Property Color As String
End Class
Public Class RedCamry
[Code] .....
I prefer this one as I don't have an extra property to deal with. But I can find a way to initialize that that list with objects of RedCamry and BlueCamry. Is it impossible or is there another way to do this?
I am having trouble setting up these classes.I need to set up a customer collection class that has one function GetCustomer(ByVal customerNumber As Integer) As Customer..The customer class reads a file and returns 5 fields and x number of records.My question is do I set up the 5 properties (fields) in the Customer class and if there are 10 records that match how do I return the customer object to the customer collection class. I don't care about exact syntax but could someone show me how these 2 classes should look?
View 2 Repliesusing a Binding Source to Bind my Collection to a ListBox? I can bind the class to the binding source, but im not sure how to let it know what type of list it is, or how to display the correct item.
I'm trying to get the listbox to display the ItemNames. Here's my class and collection class.
<System.Serializable()> Public Class SurveyItem
Private itemNm As String
Property ItemName() As String
[Code]....
Datatable object within class function + garbage collection?
View 3 RepliesI can't seem to find any answers that work. Here's the setup:
Info class: Public Class ProductStageInfo
[Code]...
maybe I just don't understand the whole collection/index/thing. All the examples I've found are regarding single dimension collections - 'how to find name within this collection', and the responses use strings to search through them, but somehow the Info class is being treated differently, and I'm not sure how to translate this..
Create composite and custom grid control in ASP.Net 2008 or above
I need to create composite control . My control like one "div" inside that div one Gridview control.
I'm trying to make a composite application.Lets say there are two regions with a view in each that interact with each other via drag and drop, view A contains a list of tasks that view b (which contains a list of People) doesn't really know about.When I select some tasks in the list from view a and drop it to another list maintained by view b which module should know what happened? does the module that maintains the tasks need to know about the module that maintains the people, or vice-versa? Where should I start?
View 4 RepliesI'm trying to create a composite control that will look like a ComboBox with a TreeView style. I'm new to this topic and I have an urgent need to create such control. I know it's not an easy task but please I need your advice to complete what I already started to build.My approach was to combined a TextBox, button and a treeview into a UserControl and make them work together as one control to achieve the control that I'm looking for (A ComboBox with a Treeview style).
So I started by creating a new windows forms control library project and I added a text box and a button as a starting point. The text box will display the name of the selected node text of the treeview and the button will show the treeview under the text box when the user click on it.
Now I'm facing tow problems with my custom control:First when I drag the custom control to a test form the resizing of the control doesn't work properly even after I used the anchor property of the text box and button controls. If I try to resize it horizontally its working find but it's not vertically.
Second I don't know how and where should I place the treeview control and how I'm going to show it exactly under the text box when the user click on the button and hide it when the user click on one of the treeview nodes.
I have a custom collection class that is bound to a data grid view object.I'd like to try to do the following from the custom element class if possible.
1) I'd like the name of the column header to be a different text than the name of the public property in the custom class. i.e. Trade_Name should read "Trade Name"
2) I'd like to try to be able to manipulate the text formatting/color of the individual collection class element's items. i.e. for a profit/loss field I'd like to have the numbers be red if they are loss and black of they are profit. I know I could do this from the datagridview object in the form, but that can be cumbersome to raise events etc.
On my custom control I've added a Property 'DisplayMode' that, at run time, does a great job of showing or hiding different sets of the standard controls. But, at design time - no matter what I seem to do, my control shows all of the child controls associated with it
View 1 RepliesI have several custom classes in a VB.NET (VS2008) project which are related to each other through generic list collections. The lower tier classes refer directly to some of the parent classes (to make it easier to refer backwards up the chain). My question is, is it possible to add the reference to the parent class when the item is added to a collection, when that collection is a property?
Below is some sampling of code to illustrate.
Public Class FlexServer
Private m_FlexLicenses As List(Of FlexLicense)
Private m_Modules As List(Of FlexModule)
Public Property FlexLicenses() As List(Of FlexLicense)
[code] .....
In the code above I have the FlexServer class which refers has two lists as properties, one for FlexLicense and one for Modules. The FlexLicense class has a property to refer back to the FlexServer class that "owns" it. In order to update this property in code, I have to add the FlexLicense to the FlexServer.FlexLicenses list AND set the FlexLicense.FlexServer property. What I am looking for is, is there a way (in the property definition or wherever) to both add the item to the list and alter it at the same time?
