I have a custom class Y which includes a public property X as list(of string) which won't always have data
In my code I am trying to do the following dim x as list(of string) = Y.X if not x.count=0 then do somthing
The problem is that when Y.X has never been set, it causes an error. What would the proper way to check for
Y.X be? I haven't really worked with lists too much.
Given
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I would like to test if ListBox1 is empty then test again until ListBox1 is NOT empty If ListBox1 is NOT empty then msgBox �You did it� and start over again, until i click a stop button
The problem is that when I start my program the listBox is ALWAYS empty and after 1-4 sec data will arrive in listBox1, but my loop (for testing if listBox1 is empty) is freezing up the application, because it�s always true and just looping infinity
I have a stored procedure (SQL Server Express) that returns a count of records:
SELECT COUNT(AdminUserID) AS CountEm
FROM Licenses
WHERE (AdminUserID = @AdminUserID);
Table "Licenses" has a field "CompanyID" which is a uniqueidentifier.
I need to add a clause to the WHERE to exclude records from the count where "CompanyID" is null/empty.
In VB code I'd do this with "If Not (TheCompanyID.Equals(Guid.Empty)) Then"
How would I do this in a stored procedure?
I want to know how to test the 1st list box if it has items more than the other list box but by one item, here is what i have: If lstInvisibleTv. Items.Count > lstInvisiblePc.Items.Count Then it works good if the lstInvisibleTv list box is greater than the other list box by one but it also works if it is greater the other one by one or more which I do not want. I want it to work just by one.
View 3 RepliesI was wondering if somone one could point me in the right direction on this.Basically I am making a proxy testing program. A user can supply a list of proxies to test. What i want to be able to do is have them be able to specify how many threads they want to run. Then have the program go through the list testing each one using the amount of threads supplied. Really not sure even where to start on this. Threadpooling?
View 2 RepliesI need to be able to tell if a property is of type List(of T)but am currently unable to. if i do
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is System.Collections.Generic.List(Of Object)
I get the following error
TypeOf (UpdateTo.GetType.GetProperty(node.Name)) Is
System.Collections.Generic.List(Of Object) Expression of type
'System.Reflection.PropertyInfo' can never be of type[code]......
I'm not sure where I'm going wrong with this. it's supposed to let the user add scores to the list, then calculate the total, average, and count. However, it doesn't let me add more values to the list. Any help whatsoever would be awesome! Keep in mind, I am new to VB and programming languages, and was just playing around with code hoping for any sort of positive result, and therefore some of the code may not be necessary, or make sense. Here's what I have now:
[Code]....
I have a query that 'selects' object of a type:
Dim l as IList(Of Foo) = (From dataRow As DataRow In table.Select()
Where CStr(dataRow("Column1")) = "A"
Select New Foo(CStr(dataRow("Column1")), _
CStr(dataRow("Column2")))).ToList()
What's happening is that if i set a break-point to the constructor of Foo and step, the constructor is hit and the parameters are loaded with the arguments. However, l has empty Foo objects (the members in every object are Nothing). What could be happening here?
I wrote a VB 2010 app on a single core processor utilizing performance counters which runs fine. However the release exe fails on my quad core, trapped by the OS on its first access to a PerfCtr. I've loaded VB Express Studio into the quad core
and when running the app in Debug I get this error "Cannot load Counter Name data because an invalid index was read from the registry." Similarly, adding a counter to the app on the quad machine results in the empty drop-downs for category and it sub fields.
where I can get an update to these registry entries?
I don't understand the error, Argument not specified for parameter 'test' of 'Public Shared Function TestThis(test As String)'.
Partial Public Class Form1
Shared Sub ReceiveCallback(ByVal ar As IAsyncResult)
Form1.Invoke(TestThis, New Object(){"test"}) 'error
[code].....
[code]...
and from VB6 project I reference to Test.dll but an error messege was appear A reference to Test.dll file could not be added (If I create VB NET project and reference to file Test.dll it OK )
Probably a dumb question, but can you write a unit test project in one language to test against another project in a different language?I'd like to translate one of our VB assemblies into C#, but want to build unit tests to verify the results. I've tried to set a unit test project up to do this, but I can't seem to access the VB code within a unit test... I can't figure out if I'm just missing/doing something stupid, or it really isn't allowed.
View 2 RepliesI have a DataGridView that has some columns with dates. It binds to an in-memory Datatable which gets loaded from an string array of data passed back from the backend Some of the rows returned have nulls for the date columns. Solution 1: If I define the Date column in the DataTable as "string" I can easily convert those nulls to empty strings and display it in the grid as empty strings (desired results). However, if the user clicks on the date column header to sort by date, it doesn't order the rows as you want. You get a purely string sort order. Not acceptable
[Code]...
This must've have been asked before but I couldn't locate it. In a mixed code project (VB and C#) we were debugging some old Visual Basic code where a statement as follows could be found:
If Request.Params("xxx") <> "" Then
'do something
I considered this a bug as Request.Params could be null, in which case the statement would've become false which wasn't the idea. So I thought. I just found out, -- probably for the tenth time and I will keep forgetting -- that the following two statements are not equal, while Nothing in VB should be equal to null in C# (thought I):
if(String.Empty == null) // always false
If String.Empty = Nothing Then ' always true
Should I dismiss this as a typical Microsoft backward compatibility effort, or should I consider this a huge error in the VB.NET compiler? Does anybody know the Microsoftean opinion on this oddity?
I have a array of strings and I am looping through them, but the string might be empty so I am trying this:
[Code]...
I am playing with the virtual machine version of the Google Chrome OS. I need a web app that I KNOW is made in visual basic to test to see if it will work with it or not. This will help determine if it's possible to make web apps for this Google OS in VB.
View 4 RepliesI have a query string called propID and I wanna check if the passed value in it is a legal integer or not to avoid throwing an error that might reveal info about my database, how can I do it? In other words, I want something like -but in vb.net- : IF QueryString("propID").Content.Type = "int32" Then Proceed
View 5 RepliesCreate an app for the DMV that grades the written portion of the driver license exam.Theexam has 20 multiple choice questions. Here are the correct answers to the questions:1=A 2=C 3=D 4=A 5= B 6=D 7= B 8=C 9=A 10=A 11=B 12=B 13=C 14=D 15=C16=A 17=C 18=B 19=D 0=DStore the correct answers in an array. The user interface form should allow the user to enter an answer for each question.When the user clicks the Score Exam button, the application should display a message showing whether each question was answered correctly or incorrectly, and whether the student passed or failed the exam.A student must orrectly answer at least 15 of the 20 questions to pass.Input validation: Only accept letters A, B, C, and D
here is what i have so far:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
[code]....
I have a large VB/SQL application that I have created a problem in. I have a table of procedures that have an active flag on them. This flag can be toggled through a user screen. Other screens access this same table to populate dropdowns. The values are stored in the table as the ID field (PK). The problem I have is that I am selecting the dropdown values based on the Active flag. If I select a record that has a procedure stored in it that has been made inactive, I get the old Object Not Set to an Instance.... error.
What I want to be able to do is check for the value in the record when populating the dropdown and allow the record to be displayed by bypassing the SQL error and just showing the dropdown value as blank while not altering the record itself. I hope I'm making sense. Code is below.but I'm back in app programming after being a SysAdmin for 20 years and I'm still rusty.[code...]
If the condition = true How do i select all records stored in .txt (temporary text file) to be updated in sql table How do i do that.
View 10 RepliesCan someone tell me if it works on windows Vista and Mac? And any other OS.
View 3 RepliesHow would a person test to see if a usb device is on? I have a program with a usb reader attached to it and would like to throw an exception if it is not on.
View 2 RepliesIn my program I need to test whether an entry is available I ue the following code:
If Not (westTF(Me.K) < 0) Then
If westTF(Me.K) Then
Exit Sub
End If
End If
This does not function, but when I remove the outer IF it is OK. ( I need to test otherwise an error is generated when West is exhausted).
I have 3 textboxes, I want to test if user has filled out only any 2 of 3. What's a good algorithm?
View 6 RepliesI was asked this question recently in a test, which I didn't pass. For the life of me, I couldn't spot what the problem was. It's probably something really obvious as well, but even a colleague of mine couldn't spot it either. The best I could come up with was issues with bottlenecks and naming inconsistencies of parameters! I blame it on the fact I've not done any vb.net for years, I've been doing C# mostly these days
[Code]...
The question: This function, although it will successfully sort a datatable, has a major problem with it.What is the problem? Re-write the function in either C# or VB.Net using LINQ.
I have found a Regex that test if the text passed to a TextBox is an email.
If Regex.IsMatch(email.Text, "^(?("")("".+?""@)|(([0-9a-zA-Z]((.(?!.))|[-!#$%&'*+/=?^`{}|~w])*)(?<=[0-9a-zA-Z])@))" + "(?([)([(d{1,3}.){3}d{1,3}])|(([0-9a-zA-Z][-w]*[0-9a-zA-Z].)+[a-zA-Z]{2,6}))$") _
[code]....
I've been looking for a tuto to use resx but I only found some where the resx depends on the localization(and the language of the browser).How can I tell my app to use a certain resx when a certain variable has a certain value.For instance I'd like to use default.aspx.de.resx when xyz=1.
Edit:I ve heard there's an issue to override InitializeCulture.
Public Class FormBase
Inherits Page
Protected Overrides Sub InitializeCulture()
[code]....
How could I access to Master.LanguageID in this class?
I work with a database, the db is on the <project_folder>database folder.
If want to open the database, Application.StartupPath returns[code]...
So I have to compile the project to an .exe to make tests.
We have a property whose job is to look up a description. If the lookup fails it should show an empty string.
So we can code the property like this:
If foo.bar Is Not Nothing Then
Return foo.bar.Description
Else
[Code]....
But are there any problems (performance, purity, other?) with just catching and ignoring the error?
You sometimes read it's expensive to throw an exception but I am not sure whether the author means it's expensive to build in exceptions using the Throw keyword (which I am not doing) or whether he means it's expensive to allow exceptions to occur (as I would be doing).