What are the behaviors difference for the Previous Property of Other1 and Other2 Class.Note than the return type of the ovrloaded Previous Property of Other2 as bean changed to Other2 while it stay as Base for Other1.
Public Class Base
Private _Previous as Base
Protected Overridable ReadOnly Property Previous As Base
[code]....
Difference between overloads, overridable and overrides .
View 1 RepliesI was familiar with the optional parameters in vb 6 and it made sense given the capabilities of the language but why the heck does VB.Net support optional parameters when there is method overloading? Which one should I use and is there a difference? If there is a difference when should I use each one?
View 4 Repliesjust want to know what is the difference between these date values?Once some one told me that its difference is server date and client date but not sure which one he meant.Below is 3 type of date currently I'm using and don't know what is the difference between them.
DateTime.Now is from System.DateTime.Now
Now is from Microsoft.VisualBasic.DateAndTime
Today.date is also from System.DateTime
Say I have, for examples sake, a class Test1,wich has a function, Test1.CreateNew, returning only a new object of Test1.
Public Class Test1
Public Overridable Function CreateNew() As Test1
Return New Test1
[code].....
I have seen code that uses the event:MyControl_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
and others the used: Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
Is there an advantage to using one over the other?
Currently im trying to write a HotKey class, however in order to intercept the messages you need to overwrite the WndProc and check for WM_HOTKEY.
Currently, im using Inherits Form inside of the class, so that it has the option of overwriding the wndproc, but along with that I get all the forms normal events when trying to handle it.
Below is my
Public Class Form1
Private Class HotKey
Inherits Form
[Code].....
How to call Protected Overrides Sub from another form?
View 6 RepliesI'm unable to find out how to do this, so either it's not possible or I'm using the wrong keywords.
Basically, I want to add something to my base class method (Overridable), so that when a derived class Overrides it, some comments appear along with the "MyBase.MethodName".
Protected Overrides Sub OnPaint(ByVal e As System.Windows.Forms.PaintEventArgs)
MyBase.OnPaint(e)
'Add your custom paint code here End Sub I want to have my own equivalent of "Add your custom paint code here".
From what I can see online the Overloads keyword is optional but is there ever a time when it is necessary? It even seems to be an error when used in a Module.
View 3 RepliesI have a question. In the framework, that was largely written before the generics came, you often see a function with lots of overloads to do something with different types. [code] and then have some kind of ifs/switch statements with typeof() to try to infer what the types are and what to do with them.What is best practise? Or what are the ideias that'd help me choose between a) and b)?
View 5 RepliesI'm trying to run this code, but it displays the error "overload resolution failed".
[code...]
Here is the full error:[code...]
I have this class Public Class DGVMod Inherits DataGridView
Protected Overrides Sub OnEditingControlShowing(ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs)
MyBase.OnEditingControlShowing(e)
Try
[Code]...
when we have a method of a derived class implementing a method of an interface which is already implemented in the base class, the compiler throws a warning (by default). when i see a warning i will try to erase it and the only way to erase this warning is to mess with the settings of the compiler hence i hope that there is a way to declare "how" a method implements an interface's method. by this i meant that we should be able to declare overridable, overrides and shadows for the implements keyword. hence if we declare overridable-implement for a method of a base class implementing an interface's method, the compiler should give no warnings when we override this implementation (re-implementing in a derived class). Similarly, if the method of the base class implementing an itnerface's method was not declared as ovveridable-implement, the derived class should be able to Shadow the implementation example code which flags unnecessary warning:
[Code]...
When I make a class that inherits from Collectionbase the overrides of ToString function doesn't seem to work properly.
Public Class House
nherits CollectionBase
[code].....
Coming from C#..I was looking at this website [URL]..And noticed that it said
public static void Main(string[] args) {is equivalent to Overloads Shared Sub Main(ByVal args() As String)
what is that "Overloads" all about?
I am assuming "No", but I cannot find conclusive proof on Google to back this assumption. Using keywords of 'vb.net "generic operator overload"' yields exactly 1 result, and removing 'overload' gives more, but no direct statement to the issue.
My thinking is given an abstract class, it'd be great to be able to implement a generic operator overload that a derived class can use in such a case when said operator overload has to return a New copy of the derived class, yet the code for each overload is the same. If that makes any sense.
This touches back to my previous questions on my custom Enum class and overloading the bitwise operators (And, Or, Not, & Xor), but, this particular thought was prompted by a mere curiosity of "Can it be done?".
Here's what one of my custom enums basically look like:
The parent, EBase is nothing special, just hosting common Name and Value properties, plus two shared operators, op_Equality and op_Inequality.
Friend NotInheritable Class EExample
Inherits EBase
Private Sub New()
[Code]....
Then (in theory anyways), calling EExample.OneA Or EExample.FiveE would work because the compiler would know to call the generic operator overload from EBase, know that EExample.Enums matches the IEnums interface constraint, and automatically supply T.
That or I'm just swimming up a certain creek here without a paddle and over-analyzing things. But it's an interesting thought, no? What is StackOverflow's consensus? Do I need to lay off the Spice a little bit?
PS: I use /* */ style comments because Markdown doesn't handle VB-style properly.
PPS: I know that, in the last example, Return New T( ... ) is invalid, but I can't think of a proper syntax that would articulate the basic idea.
Do you really need this keyword to overload methods? What is the difference between using the overloads keyword vs. just having different method signatures?
View 5 RepliesI am trying a example codes of animated graphics. I rewrote all the code and I found an error which doesn't happen on the example code(I run the example project)
error: 'Protected Overrides Sub Dispose(disposing As Boolean)' has multiple definitions with identical signatures.
when I double clicked the error, I got this in Form1.Designer.vb:
'Form overrides dispose to clean up the component list.
<System.Diagnostics.DebuggerNonUserCode()> _
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
[Code]....
I have recently come across some code that has the following. First there is a Interface with the following function Function Validate() As Boolean. That interface is then implemented in the an 'ABSTRACT' class like this.
Public MustOverride Overloads Function Validate() As Boolean Implements IBusinessEntity.Validate
Question 1: Why use Overloads in the Abstract class implementation.
Question 2: The Abstract class is then inherited into a class (TestClass). In TestClass the Validate function is implemented as follows Public Overloads Overrides Function Validate() As Boolean. I understand the Overrides keyword is to insure that this is the version of the Validate that you want called and not the Abstract class version but why again use the keyword Overloads?
From what I understand you can overload a constructor of a class by simply changing the constructor signature. Also, you overload Methods and Properties of a class by using the Keyword Overloads. But why do it when your implementing an Interface method, or an Abstract Class method that's inherited.
I am cleaning up some code and I have multiple classes that are 99% exactly the same. So my understanding is that my options are...
1. Create a class and all other classes inherit from it and modify it a bit
2. Create an abstract class and all classes inherit from it and modify a bit ** I took this route
3. Create an interface and all classes Implement that interface.
Here is my 'original' class below (the one that all of them look 99% identical). This class is used in an arraylist so I have a listing of all my images from a folder I have searched.
[Code]...
I've got question. I created this;
Public Overloads Sub AddTextLeft(ByVal Text As String, ByVal Fontsize As Decimal, ByVal Bold As Boolean)<br/>
'-- PBA / 22.08.2006<br/>
[CODE]...
i'm accessing an access database and want to execute the following query
INSERT INTO sometable
(date, field1, field2)
SELECT ( ? AS Expr1, field1, field2)
FROM othertable
? is a date i generate in code and field1,field2 belong to othertable i put it in a tableadapter and execute it by me.tableadapter.queryname(calculated date) but i get the error : Too many arguments to 'Public Overridable Overloads Function queryname() As Integer' Also if i try to generate the date in the query builder in the form dateserial(year(now),month(now),1-1)the query builder does not accept it?
I'm following this tutorial: [URL]..except I'm connecting to my own data source - a MS Access database.This is the query I have setup with the dataset:
SELECT Terminal_ID, SUM(Transaction_Quantity) AS Total
FROM tblTransaction
WHERE TransactionType_ID=3 and Transaction_DateTime>[@fromdate]
GROUP BY Terminal_ID
The debug fails immediately because it needs the extra parameter so I change the code from:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'tetrisDataSet.tblTransaction' table. You can move, or remove it, as needed.
Me.tblTransactionTableAdapter.Fill(Me.tetrisDataSet.tblTransaction)
[code].....
The error I get on build is:Too many arguments to 'Public Overridable Overloads Function Fill(dataTable As tetrisDataSet.tblTransactionDataTable) As Integer
...I gave it the extra parameter, so what gives? Something special I need to do as it's a datetime field?
After having some trouble in my own code using String.Split and the Split(String(), Int32, StringSplitOptions) overload, I decided to look to the MSDN.I copied the entire VB.NET code example from this link: url...I placed it in a new class, and received the following errors (same errors as my own code example):[code]Why can my code not recogognize the string() parameter overloads to String.Split? Remember, i took the code from the MSDN link above, copied and pasted and it still did not work.I am counting on using the string() instead of char() overloads shown here: url...
View 15 RepliesI read somewhere that older VB .net (pre VB .NET 2005?) couldn't use overloaded operators in a C# class. Is it true for overloaded cast operators?Either way do you guys think it's a disadvantage for a C# class library not to include them and arithmetic methods as actual methods for other languages, like:
ToDouble
ToFloat
FromDouble
Add
[code]....
I'm under the impression that these two commands result in the same end, namely incrementing X by 1 but that the latter is probably more efficient.If it is correct, why should the latter be more efficient? Shouldn't they both compile to the same IL?
View 17 RepliesPASTE ALL of this to your Form1 code window please and add one Button to Form1.
Now I am asking developers here who actually do software development for a living
especially those persons holding MCPD or similar Microsoft Certification please.
1) When redeclaring a method as in AnotherClass below which Inherits from ExampleClass,
is the recommnded way to use SHADOWS or OVERLOADS please? 2) What about when you do the same with a PROPERTY please?
Option Strict On
Option Explicit On
Option Infer Off
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code]...
I've developed a .NET application that, among other things, does the following:Uses WebClient to retrieve data from a remote server.
Serves as a socket server to 2 'satellite' applications run on the same machine or on a LAN.When I run the app in the VS IDE, it works great. It quickly gets the data from the remote server and communicates perfectly with the 2 satellites.However, when I build it and run it as an EXE, the response from the remote server is very slow and its communication with the 2 satellite applications become very poor.Is there some important difference between running an app in the IDE and running it as an EXE that could effect it like this?
For every member object I have to declare the variable 3 times.One in the declaration. One for property declaration. One to tell the compiler to synthesize all the function. Another one to release all those members from memory.Then I learn about Core Data. I generate diagram, poof the classes are made from me and a lot of things are done behind the screen of that visible classes.
Basically Core Data in Objective C represents some form of relational databases. Of course those databases can have relationship, including many to many relationship. The additional detail of having a third table for many to many relationship is already done.Then, there is indexed property so we can search faster. That's also done.