Converting Types Using Custom Classes?

Sep 16, 2009

I'm studying for the MCTS exam 70-536 and have come across the following question:Given the following Visual Basic code sample, which interface must the custom class MyClass implement?

Dim a As MyClass, b As Boolean
a = 42
' Convert using ToBoolean.
b = Convert.ToBoolean(a)
Console.WriteLine("a = {0}, b = {1}", a.ToString, b.ToString)

Before even looking at the possible answers, I can't get past WHY on earth would we be converting the number 42 to a Boolean value?? I tried this and as I suspected it did NOT compile! Is this a trick question or am I missing something? I realized that in order for the code to work, I would need to implement one of the interfaces shown in the multiple choices. STILL, would there EVER be a purpose for this particular conversion?

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Apr 10, 2012

I have two Parser classes that inherit from a base class, BaseParser. I want to use either class as a parameter in another Monitor class. The Parser classes, CS600 and TCH600, both have two properties, RawDataList and SummaryDataList. The CS600 class's RawDataList returns a List(of CS600Data); the TCH600 RawDataList returns a List(of TCH600Data). The SummaryDataList returns similar classes in each Parser class. CS600Data and TCH600Data derive from a base class, BaseData.BaseParser also has RawDataList (List(of BaseData)) and SummaryDataList (List(of BaseSummaryData))The Monitor class has a private field, _thisParser which can be either of the two concrete Parsers above. I want to be able to call and use RawDataList and SummaryDataList of _thisParser within Monitor class, but when I construct the concrete Parser classes, Visual Studio notes that the RawDataList property of CS600 cannot override the RawDataList property of the BaseParser because they differ in their return types.

I thought that since CS600Data derived from BaseData (but also adds some new properties of its own) that I could use CS600Data wherever I use BaseData. What am I misunderstanding? How can I correctly construct these classes?

Public MustInherit Class BaseParser
Protected _rawDataList As List(Of RawGasData.BaseData)
Public MustOverride ReadOnly Property RawDataList() As List(Of RawGasData.BaseData)

[code]....

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Converting types between .Net and VB6?

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********** Start Code*********
Dim numberOfBytesToRead As Integer
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Dim newRecievedData(numberOfBytesToRead - 1) As Byte

[Code].....

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Public Class Form1
'Define the Module level variables
Dim FutureValueInteger As Integer

[Code]....

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In Delphi you can do something like this :

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where you can then declare
T2Array = array[1..3] of TArray

[code].....

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[Code]...

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M[Code]...

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MsgBox(
New
TreeNode("Today").IsSelected)

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Mar 23, 2012

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<WebMethod()> _
Public Function MyMethod() As MyType
Dim myValue as new MyType
return myValue
End Function

In my consuming code I created a web reference to the service and the proxy classes were created. I gave the service the namespace "WebService". Next I try to make a call to the service and assign the result from the call to a variable, something like this:

Dim service As New WebService.ServiceNameSoapClient
Dim response As New MyType
response = service.MyMethod()

I get an error from the IDE saying that it cannot convert type mynamespace.WebService.MyType to mynamespace.Entities.MyType. It appears to me that although the types are similar they are being treated as different because of the different namespaces, which makes sense of course.

Edit: So from what I am reading I believe this is by design, that is the proxy types are simply different types and cannot be directly associated with the types in the consuming code.

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[Code]...

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So, I added my setting as shown in this image.

On load I do this:

If My.Settings.databaseConnectionSettings Is Nothing Then
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End If

[Code]....

So, the question is, how do I get that arraylist of my DatabaseConnectionSettings saved to persistent storage? I want to do this in the cleanest way possible. That is, I don't want to have to convert it to a string or save it to a separate file every-time I want to use it. I would like to be able to use the My.Settings accessor method.

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Here are 2 examples of function in my calling code. This should indicate the type of list and the stored proc used to get the data:
Public Function getTheEyeColors()
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[Code] .....

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I Have just been watching a video on throwing Exceptions. Are you supposed to throw System.Exceptions from within your custom classes. to the calling code, Which other way can they communicate. I have read in several places it is bad practice to throw SystemExeptions.

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<Serializable()> Public Class Point
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I am in the process of converting some c# code to that of VB.NET...I am running into error at the following

[Code]...

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Public m As Sub(ByRef d As Dictionary(of String, customObj))
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[code]....

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2) Nested function does not have the same signature as delegate 'signature'. Seen while hovering over anything after "ToDictionary".

Q1) How far off am I in each of the implementations?

Q2) Which one is the computationally least expensive? Why?

Q3) Which one is the computationally most expensive? Why?

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VS 2010 Structure Classes So That The User Interfaces Though A Single Class While The Supporting Classes Are Hidden From Their View?

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Public Class MyInterface
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Public Sub New()
MyBase.New()

[code].....

So you might ask why am I even separating them? It's strictly for others who will be working with this interface. I need to funnel them though a logical structure:

interface.Economic.MyMethod
interface.Currency.MyMethod
etc

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