Is it possible to create a class in VB.NET that can be compared to a string in a switch statement? For example, let's say I have a class Foo:
Public Class Foo
Public Bar As String = "test"
End Class
Is it possible to implement some interface or override some equality operator so that I could use Foo like so?
Dim foo As New Foo()
Select Case "test"
Case foo
' It worked!
End Select
I was reading an interesting article here and it made an interesting point about the 'case' statement in vb.net vs the 'switch' statement in C#, which I've pasted below:The following Visual Basic Select Case statement can't be represented in C# with a single switch statement:
Dim Condition As Integer = 55
Select Case Condition
Case 1, 3 To 5, 10, 12, 14, Is > 50
[code]....
I've always found the switch statement in C#, with dropthrough and consequentrequirements for a break in each case, to be a bit unwieldy. Is there any reason they haven't enhanced the switch command to allow these situations? W
EDIT AFTER CLOSE: I'm surprised this was closed, really. With the number of extension methods and helper classes I've found online for other things, I thought an enhanced 'case' would be a good chance. I somewhat hoped a luminary such as Jon Skeet may have commented on the background reasoning, rather than the individuals below who've obviously thought 'religious debate' as soon as more than one language is mentioned.
I am writing the code as on if statement that if the html class has strings called "<a id=""rowTitle1""(.*?)</a>" then do something. In what property that come after pattern that I could check the string whether if it valid or not??
View 13 RepliesI have about 100 strings that depend on an integer value. There is potential for the list to grow to 255. What is the faster/preferred method of assigning the string based on the passed integer, a hash table or a switch statement. I googled around and can't seem to find anything that compares the speed of the hash table lookup vs. the speed of the switch statement. Is there an easy way I could measure the speed myself or any links to articles describing the performace of each method?
View 4 RepliesI am using VB.NET and I can't compare the radio button lists selectedItem.Value to a string, it doesn't work...here is the code: (I have also tried selectedValue it does not work either)
[Code]...
Why won't it evaluate that rblOne.SelectedItem.Value = "No" !?!?!? I tried rblOne.SelectedValue, that doesn't work, AND I added .ToString to both, which did not help, I even tried it w/ "No".ToString...this doesn't make any sense.
Say I have this in VB.NET:
Dim executeB As Boolean
Select Case myVariable
Case "a"
'some code
Case "b"
'some code
Case Else
End Select
If myVariable is "a", control will go into the first case statement. Now let's say if myVariable = "a", but inside a's case block, I find that executeB is true, is it then possible to jump to the second case?
[code]How would I switch on an object's type but using VB.NET's Select Case?I'm aware that some might suggest using polymorphism but I'm using a hierarchy of small message classes so that really wouldn't work in my csae.
View 6 Repliesi am creating an alarm clock application which requires user input to switch off the alarm. I have 3 comboBoxes on the form named day month year. when the user enters the correct date ( Current date) and click the button the alarm is deactivated. the code to check that the date entered in the comboBoxes is the current date.
View 3 RepliesI have a little problem with application setting in VB.net 2008. I want to switch main server and backup server connection string with combobox. [Code] It did change the Application Setting connection string in the main form when combobox1 was changed. But the problem comes, when child form was called. On the child form there is DataGridView with Dataset using application connection string. Even the Backupserver was selected on the main form, child form dataset connection string doesn't change. I don't know how to pass the current connection string to child form dataset although it is set to use application setting.
View 6 RepliesI've createda vb.net class library where I've defined a number of small classes... nothing complicated, just working with strings, sending emails, etc.In another project, I reference the class library and I'm seemingly able to create an instance ofone of tclasses - intellisense shows me all of the plic properties, methods, etc... all looks perfect. No compile errors at all, nothing b gumdropsand lollipops.When I run the app I'm working on that references the class library, it fails at the point where I'm creating an instance of the class and gives me a vague exception, "System.TypeLoadException".
View 2 RepliesThis may be simple, but im having a tough go at it. I'm trying to make a "review" section in a step through form, where the user can see everything that has been entered and if they choose go back and "edit" that information again. One section only has to show the information that has been added by the user, basically if they don't select a certain checkbox there is no reason to display the info for that box.I want to to dynamically create labels in a Panel (Panel7) on a TabPage (TabPage3), only for the checkbox information that was selected. This is what I have right now, and I am unable to see anything on the page, I have also tried without the panel and straight onto the tabpage itself to no avail.
MsgBox(CurPat, MsgBoxStyle.Critical)
If (CurPat = "True") Then
Dim lblTemp As New Label
[code].....
please tell me what is below code doing? is it creating array with two values or its creating to string index which will take value later? [code]
View 4 RepliesIs there a way to pass data from a Select Case statement to an array? i.e. I have a gradebook program I'm working on which specifies that I'm to create a form with a menu that will open another form which has textboxes for 5 student names and 5 grades for each. I need to use an array that holds 5 student names (done), an array of 5 strings to hold each students' letter grade (?) and 5 arrays of 5 numbers to hold each student's set of test scores (done). What I can't figure out is how to get th
Public Class StudentData
Private Sub btnOk_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOk.Click
[code]......
I am trying to insert into a DB with has the following columns:
ID (autonumber), BonderIdentifier (text), Username (text), Login (date), Logout (date).
BonderIdentifier, Username, Login is the PK.
Here is what I do:
Public Function submitNewToDB(ByVal sessionData As BonderSession) As Boolean
Dim cn As OleDbConnection
Dim cmd As OleDbCommand
Dim str As String
[Code] .....
Like I said I get an insert into error and I dont know why. Nothing is in the DB yet and the table is created. I ran the built string in Access as such:
Insert into Session ([BonderIdentifier], [Username], [Login]) values ('Mork', 'sean', '2/23/2010 11:12:42 AM')
And it works.... but in VS it doesn't.
I am trying to write a Function which will return a data table, filled with a data from a database.
The Function will accept 6 diffrenet parameters as Optional. Each one of them will be an additional condition to be added to a where clause, if it`s provided when the function is beeing called.
Is there any method in .NET to simply add a new condition to the where clause?
I have a IF statement which is checking each row in the data table (for a match) and ELSE statement with commands which are executed if the If statement is not satisfied. Now I would like to write like so that it goes to the Else part BUT ONLY for values which are not satisfied in the IF statement. If I am more specific; I would like to calculate values if a match is found and just print them if it is not fond (usually there are both cases). Now the problem is the bold text; if there is a match found I don't want it processed BUT if the match is found I do. How can I write that?
currencyPosition = 0
Dim d As Integer = w + 100
For Each currency In Ary
[CODE]..........................
I have an SQL statement which i need to code in vb:
CODE:
Notice the fields prodno1 and prodno2 in the table structure.. this is part of a number of sql statements i need to run and put inside a loop. my problem is i want to automatically use this same code such that on the next loop, this sql statement is going to be:
CODE:
Note that in this "2nd loop"
- the table name is now r3 from r2 in the first SQL statement
- there are now prodno1, prodno2 and prodno3 instead of just prodno1 and prodno2
- in the WHERE clause, the p.prodNo becomes p.prodNo2
And so on and so forth.. so for the 3rd loop
- there's going to be r4
- there's going to be prodno4
- in the WHERE clause i will use p.prodNo3
In VB.NET projects, errors are highlighted immediately after cursor leaves the line. In C#, I have to wait several seconds for IntelliSense to highlight it. Also, the C# version doesn't show all project errors in "Errors List", unless you start to build it. Actually, it seems to work differently in every way. Is it possible to adjust that behavior?
I am using both Visual Studio 2008 and Visual Studio 2010.
Yesterday I was at an interview where my interviewer (who admittedly didn't claim to be an expert on the subject) stated that "VB.NET is more weakly typed then C#" - (At the same time he couldn't recall an example). This statement seemed incorrect to me (particularly given that both languages use the same framework libraries for their types) and I advised as such and that perhaps he was confused with the option to turn Option Strict or Option Infer on/off.
At the same time I know that VB.NET has situations where it will do type coercion - leading to occasionally unexpected results (although I also cant recall under what conditions) - (Actually I think I just remembered that it was mainly when performing arithmetic operations with different types - whereas other languages will force you to be explicit (?) ).
I have an interesting issue I've run into where I can easily tap into python code from VB in an excel instance, as described here: Calling python script from excel/vba.However, when I mimic the exact same code structure in visual studio in a form, the pyscript.language = "python" line fails. Does anyone know if MSScriptControl.ScriptControl can be used in VB .Net to control python like you can in excel? This would be a lot easier than setting up a com object for my python scripts.
Example code (need to add microsoft script control 1.0 and excel object library):
[code]...
I have a form called 'Form1' in my .NET Project.
When I double clicked the form it went into the code editor.
However, I accidently deleted the statement
Public Class Form1
End Class
how can i get this code back?
In Visual Basic what do you have to put between the objects to input a class statement?
Class class1
object1
object2
[Code]....
I have 2 arrays one is a and second is b. how do i compare each of them and insert to new array c?[code]...
View 10 RepliesI've been developing databases for research using ms access for the last few years. The application is used on accross a hospital network and while it was slow initially, itstarting to come to a grinding halt as numerous users are accessing it at once. I've been debating whether to try and develop the front end using vb.net in hopes of making the application faster.Does anyone know if this would be the case?
View 1 RepliesHowever, for several years now, I have been working primarily in the .Net space. Initially, my transition into the .Net world consisted of writing and maintaining VB.Net code. VS provided almost all of the nice intellisense support I came to expect after years of working with the Eclipse/Java combo. Eventually my employer decided to do new development in C#. My initial impression of the intellisense support for C# was less than stellar. At times it seems as if VS has no background compiler for C#, but occasionally it does something smart, indicating there is some background processing there, but not quite enough to really boost productivity in meaningful ways. Is there any sane technical reason for this discrepancy regarding intellisense support between the two languages?
View 4 RepliesI have been doing this project for couple of weeks and i get stuck and cant find a way to do it. I need to compare this 2 txt files. So if the data in FILE A matched data in FILE B, the quantity in FILE B need to deduct the one customer bought and replace the new quantity. For example:
[Code]...
If I have the following structure:[code]How can I select it in a conditional like this? [code]I know that myUsers.Contains(.ID = "1") is totally wrong, but I am curious how to do something like that?Is it possible? Is this a job for LINQ?
View 3 Repliesclass
eg: dim classobj = xyz("CLASS_NAME") ' where classname is a valid class name
and dynamically raising a known method of that class on that newly created object or class reference.
[code].....
I need to write software that will do a lot of math. Mostly it will be matrix multiplication with integers to compute DCT. How much faster should I expect the code to run in native c as compared to VB .Net? Factor of 2, factor of 10, factor of 1000...?
View 3 RepliesI am working on a large project with hundreds of dll's being used on the same machine, on the real large windows there is latency issues that I would love to address. The VB6 project was quick and effective but dotnet is bulky and slow compared to vb6 version, what changes from vb6 to dotnet would increase performance and reduce latency in the larger windows?
Working with VB08 3.5 Framework so parallel isn't going to work sadly, what other methods are there from a code standpoint could I use? DUring the conversion process could it be using parts of code that bog the system down?
