Given that a typical coding mantra is "Don't induce side effects in method calls." and that the only reason (that I know off - please enlighten me if I'm wrong) to not use short circuited operators is when you depend on the side effects of a method call in subsequent code. Why isn't the default operator in languages like C# and VB.NET not a short circuited version?
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I found using AndAlso/OrElse, all the time, VERY annoying. It reduces code readability, especially when conditioning get complicated.
View 2 RepliesI recently installed visual studio 2010 and am using visual basic.The problem I am having is that some operators do not show up within the editor. For example the code line below
test = 3 + 5 - 6 / 7 * 4
only displays
test 3 5 - 6 / 7 * 4
the = + operators are not visible although they are there since the program will work as intended....and if I open up the .vb file in notepad everything is there. It just won't display within Visual Studio.
i want to delete some files but only if they aren't in use. What i did was a try/catch:
Try
My.Computer.FileSystem.DeleteFile(fileInfo.FullName)
Catch ex As Exception
End Try
but it seems that this method is very slow if i try to delete some files over network.
Is there an faster way to delete files? Is it faster to check first if an file is open? If yes, how can i check if an file is open?
I have about 10 settings in my app which are set during coding, but the user can change them during the running of the app. They should then be saved so the same settings are there the next time the program is run.
View 1 RepliesI've just about scrambled my brain on this, searching and trying things, so I'm hoping someone sees something that I'm missing or can explain it to me. I'm new to .NET, used to do a lot of programming in VB but that was many years ago.
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How many times have we seen this type of selector:
I was just about to start creating this in a WinForms app, when I thought that others may have some ideas for doing this better. We need it to sort - so the right hand list will need up/down buttons. But this seems so old school. I love devexpress components, and was thinking of asking them if they would consider adding a component that handles this functionality with a slick UI.
I am thinking that a graphical representation of the objects, and a graphical representation of the listboxes - that would be a more intuitive way to move items around. Has anyone seen an open source project like this?
I don't know how to get my asp code to work on windows 7. I ran my project, it works correctly.
But for some pages I'm getting an HTTP 401.5 error.
Right now I'm trying to make an alarm clock program.I know my coding is correct and I'm not geting errors. Also my sound is a .Wav and was properly inserted into the resources folder. I was wondering if there is just some dumb setting that needs to be changed or if I'm forgeting something in the code.[code]...
View 4 RepliesI found some code on the internet as below (slightly modified).It simply requests the content of a webpage.However I get two warnings:
Warning 1 Variable 'srRead' is used before it has been assigned a value. A null reference exception could result at runtime.
Warning 2 Variable 'Str' is used before it has been assigned a value. A null reference exception could result at runtime.
I know I can simply forget about the Finally and add the code to the try block.Will that be the way to go or can I prevent the warnings using a different approach?
I'm using BitBlt and GetDC to capture windows and save them to a bitmap, but a window that is covered or overlapped by another window appears with that window showing over top of it. Is there a way to stop this from happening? I have the window handle available, the graphics context, and a Process object.
View 5 RepliesIf you make a Control's BackgroundColor Transparent and put it in front of another control, the other control doesn't show through. Why not? GDI+ makes this easy, doesn't it? Why don't Windows Forms use it?
View 10 RepliesI'm refactoring VB.NET code where methods routinely run five hundred lines and the references are so tightly coupled that the code defies simple refactoring such as method extraction. And that's why I thought I would try regions within a method body. I just wanted to organize the code for the short term. But the IDE didn't let me (resulted in a compiler error.) I'm just curious as to why? Seems like code regions shouldn't impact the compiler, intellisense etc. Am I missing something? (Still using VS 2005 btw.)
Interesting: This seems to be language specific. It's OK in C# (I didn't check that initially) but not in VB.NET.
public module MyModule
Sub RunSnippet()
dim a as A = new A (Int32.MaxValue )
[code]....
that gets a compiler error but the C# version is ok.
I'm developing a Windows Service, but for some reason, the changes I'm making to my code file aren't taking effect. I clean, build, and rebuild the solution as well as all the files that I'm changing, but nothing's happening.Is this a problem with the installation of the service, or something wrong with my IDE? I just now thought that maybe I shouldn't be rebuilding the files...
View 11 RepliesI am building an application that accepts input entered into textboxes, then checks the input for negative values, etc. before writing it to a file. If the data does not meet the conditions, a message box pops up letting the user know. The problem I am having is that after it checks the data and displays the message box, it continues to save the input to the file anyway. How do I make it only write to the file if all the data meets my conditions?
View 1 RepliesOption Explicit On
Imports System
Imports Microsoft.VisualBasic
Partial Public Class _Default
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I am getting error in the sheets and iffset liness.. it says
Sheets("Sheet1").Cells.SpecialCells(xlCellTypeLastCell)Offset(1, 1).End(xlToLeft).PasteSpecial(xlPasteValues), underlined words aren't declared
So I've been working with DotNET for a few years now; long enough to establish solid preferences for one available element over another, one available logic over another, and then to develop preferences for aspects of elements and logics.
The one that conflicts me the most is the stock Settings construct. It's a great idea - I mean everybody needs basic data persistence that isn't worthy of databasing, right? It's implemented in a way that anybody - and I mean anybody from flat beginner to highly advanced - can benefit from it. It does some heinously stupid stuff, though; for example, it angers me (and I mean full-on, where's my crowbar-OK-now where's the silly @#*! who came up with the idea anger) that the only way to save it is the way that's hardcoded in. The .SAVE method takes no parameters, there's absolutely zero exposure for the save-path to provide a more deliberate location, so the only place any settings ever get saved is in a ridiculously long (and literally arbitrarily designated) user-profile-based path.
So what happens if/when a user is ready to upgrade their OS (or just reformat and reinstall their OS, which the kinds of people who end up on my client list are prone to do just as part of quarterly maintenance), and they want to save their personal application settings to load in the next time around? They either have to hunt out that moronically obfuscatory save location or I have to write special (and I mean riding the short-short-short bus special) code which is more or less a whole new settings class identical to the settings classes implemented in the application to begin with, just to allow them to export their settings to a known location for transfer.
And what happens if a specific setting needs special treatment beyond the basic 'changing' and 'changed' events provided by the stock class? Since any change to the Settings Designer rewrites the whole code-behind property declarations, I can't do it in that code file; I either have to extend the Settings class or get back on the short-short-short bus and write that special 'mirror-class' again.
I'm not much for just general whining though, so some time back I wrote my own serializable classes (designed for specific data persistence, like generic/universal application settings and then also MySQL server connections/credentials and then also form properties and then also application-specific settings) along with shared save and load methods which give me more control over where settings get saved. These classes have evolved over the last year or so until they're actually pretty awesome (even if that's
just my opinion)... I've even implemented full on-disk and in-memory encryption functions for applications that need different privilege levels, to prevent any tampering at any time.
And then a multi-user application project comes along and suddenly each individual settings class needs multi-user support based on the Windows user logged in, and suddenly the stock Settings class is the best option again even though it's still the worst possible option in settings persistence.
So what I want to know from this discussion is this:
How do YOU handle application and user-settings persistence? Is there something really key that I've been missing all this time that makes the stock Settings class more than absolutely worthless (which has been my opinion since about the first time I ever had to work with it)?It never hurts to try. In a worst case scenario, you'll learn from it.
My DataGridView1 does not show the data on my testdb.mdb i need to fix this first before i continue on adding records on my db.
Imports System.Data.OleDb
Public Class Customer
Dim con As OleDbConnection
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Is it possible to define operators like addition, subtraction and such to classes? I'm trying to convert a vector class from C++
class CVector2
{
public:
float x, y
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I want to place the arithmetic operators in an array so I can randomly select one at a time. I am not sure how to declare and initialize them so that I can use them in an equation.
View 11 RepliesWhy aren't the assignment operators (+=, -=, *=, /=) overloadable in VB.NET?
View 1 RepliesDid anyone else read this article under Visual Basic News? I thought it was a very bad treatment of the subject. I especially don't like articles like that when the code they post relies on Option Strict Off.
View 12 RepliesAs a learning experience I decided to try and implement the Shunting Yard Algorithm(string calculator) using OOP. It was successful for as far as I took it, but it had one flaw. In order to get the stack to be accessible from the operators I had to declare it as shared, which meant that all versions of the calculator shared one stack. This very short piece of code illustrates what I came up with and the "flaw". [code] How can I maintain the functionality of anOP.add1 without declaring "something" as shared?
View 9 RepliesAccording to MSDN The And operator can act as a bitwise operator OR a logical operator.The only way to know if it is used as One operator or another is, If it is on the right side of an assignment operation? for example x = 3 AND 5. I cannot find any other instances where the bitwise operator would be used instead of the logical operator, are there?
View 1 RepliesHow do I bitwise shift right/left in VB.NET? Does it even have operators for this, or do I have to use some utility method?
View 4 RepliesCan I store the common operators such as '>', '<', '+' etc., in a variable and then use it when required.
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so here instead of directly using > and +, Can I use the variables OP1 and OP2 somehow. May be I can put the entire string from "If..... NUM1" in another variable as text string and then execute that variable.
Using 2 objects of the same type, I'm trying to implement < and >, but I can't seem to find any authoritative source on what to do with either or both being Nothing. In other words what the accepted practice or MSDN suggestions are.[code]Accessors is my canonical method for centralizing an enumeration of the properties (all are decimal)return false for both if either is Nothing?I found a comment, but can't seem to verify or validate it that A null object is always less than a non-null object..
View 2 RepliesI'm working on a project to replace ADO.NET data access logic using NHibernate where we're not able to map the entire domain model at once. This means we'll have domain classes with property mappings to other domain classes that aren't yet mapped with NHibernate.
Consider a Person class with an Address property (Address being a domain object without an NH mapping and Person being the class I'm mapping). How can I include Address in the Person mapping without creating an entire mapping for Address? Is it possible to call legacy (ADO.NET) data access logic from a custom PropertyAccessor? If so, is it reasonable?
*I asked this within another question here but didn't get a response. I'm hoping to get one in a more concise question.
I have a weird situation. I have a C++ code that overloads the +,-,* operators and exports them in a .DLL file. Now, I want to import those overloaded operators from within VB.NET code. So it should be like this:
<DllImport("StructDLL.dll")> Public Shared Function
Operator +(ByVal a1 As A, ByVal a2 As A) As A
End Function
So what I'm trying to do above it just import the lovely overloaded operator + from the DLL.Note that the operator is already overloaded from inside the DLL, so should I import it as a Function or as an Operator like this?
<DllImport("StructDLL.dll")> Public Shared
Operator +(ByVal a1 As A, ByVal a2 As A) As A
End Operator
The overloaded plus operator is supposed to add structs. So the DLL is programmed to work on structs (C++) and I want to import it in VB.NET to work on Structures.
I have a custom class that simply contains a public variable X.Let's say I have two instances of the class, A and B.If I execute an assignment operator, such as:A = B then I want A.X equal to the VALUE of B.X.But, I'm pretty sure that this will just assign B to the variable A.Assigning pointers, in C++ lingo.I looked in the VB.NET docs, which state that "The operator can be overloaded only as a relational comparison operator, not as an assignment operator."
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