I have started researching Reactive extensions and I would like to know how to do the following (ill try and keep it simple):
1) have a list of string (or any other type)
2) when an item is added to the said list, do something with it...
Guess im just kinda stuck where to start :/
I tried to implement something that in C# is:
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I am creating a program which can store files, and I display their names in a list box, with their contents in another list box. My program can read the file names but has the file extension ".txt" added to all of them, meaning that the program cannot read the contents. How can I remove ".txt" from them? [code]
View 3 RepliesHow would I loop through a directory recursively, and get a list of ALL file extensions used, not duplicating any of them? It could just output to the debug window. Or perhaps write to the database and have the database filter the duplicates. So it would be great to see...
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I'm writing a program that reads a directory of xml files (not well-formed), parses the xml, and dumps the data into an Excel Workbook.The file contents are similar in that they have many common xml nodes/attributes.Some files have additional nodes/attributes.The xml in these files represent configuration settings for a Web Application, one file per user.The expected output is a worksheet with a column for each node/attribute combination and a row of node/attribute values for each user.I'm just about finished with the program, but I've run into a bit of a snag.As the final step in the process, I need to loop through a generic list of array objects (that represent a user row) and send the array elements to Excel.I don't know the correct syntax to get the array objects out of the list and have been unable to find sample code specific to generic lists of array objects.[code]
View 3 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)
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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.
I want the Function to accept List(Of String), Array & String and similarly return List(Of String), Array & String respectively. The Function simply adds a string (month) to the input collection. I just want to use it for string, array and list with needing to think of conversions.
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I got an object of List<List<string>>I need to bring this into a ist<string>I have no idea how to do this with LINQ.
View 1 RepliesI am using the following lines and am not able to concatenate the needed values, why it is not working.
Dim rxBuffer As String = " "
Dim rxData As String = " "
Dim rxDataStringBuilder As New StringBuilder[code].....
We're working on a big ASP.NETVB.NET website project. I need to populate three dropdownlists. To last two are independent of the previous ones. The population data comes from an SQL Server. I'd have no problem doing this with code-behind with post back but we don't want any PostBacks so I started to develop this in AjaxjQuery.
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I'm trying to solve a problem regarding types of list. First of all I have a stored procedure in my DB which does a select of a single column and I try to proceed it in my app in VB. By making a method function I declared a DataTable that loads through the SqlCommand(with the CloseConnection behavior). After that I publicly declared a List(Of String) which needs to be populated with the rows/items from the stored procedure that is on the way. Below is my snippet of the code:
Dim dt As New DataTable()
Try
If conn.State = ConnectionState.Open Then
[Code]....
It's LPrefix = collection.Cast(Of String)() where I get an exception error telling me that I can't really convert it. The old fashion way is to iterate with for/for each loop but that's not what I want for best use of performance especially if the list will have thousands of rows from a single column. So basically, I want to insert those items from that DataTable to the List(Of String) without For/For Each loop.
Running on VisualStudio2010 Ultimate, .NET FrameWork 4.0.
I added a login form in the end of my vb 2008 gymnassium project. ie i created it last the form coding is right but when i execute the project,the list button(the coach,member,supply lists) doesnt work when i change the startup of the project to login_form it works when the startup in the project properties is Main_form. what to do?is there some arrangement problem?or startup problem ?or something that im not doing?
View 3 RepliesI am trying to solve a mystery in VB 2010. I tried to look up in many places for the code or an example but every thing I have found was outdated. So, all I need is a code which will produce a file list of my ftp server/folder which will be transfered to ListBox object. Here is another thing. Everything I need in the ListBox is only a file name and its extention:[code]
View 10 RepliesHi
I could sure use some help. In a form of a push in the right direction. I am tryig to remove all multiple tcode (stock name) and add (if tcode is "B" add the shares and if tcode is "S" subtract the shares) them together in just one line of text in a label and if the shares add up to 0 after subtracting the shares bought and sold than don't add it to the the label.The following are my total trasactions for id# 111
tid , tcode , ttype , tshares , tprice
111 frd B 500 $300.00
111 frd S 100 $320.00 (500- 100 = 400)
111 frd S 100 $250.00 (400 - 100 = 300)
When I hit the summary button it should display
tid , tcode , tshares , tprice
111 frd 300 $275.00
I know I am only working with total shares(tshares), Im not sure how to put it so it will read only one line of the frd stock. I think I have to subtract each stock as it goes in a loop but I am not sure how to apply it to my code. I already used a loop to read each line, I think I need a for loop somewhere. I tried puting it in different locations but it will not work..here my code.
Private Sub btnSummary_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSummary.Click
Dim tid As String = ""
Dim tcode As String = ""
[code]....
This is my first time posting here although I have been lurking for quite some time. I'm stuck with a problem I have seen before and never solved: I have a long list (~23,000) of alphanumeric strings that I'm reading into a List(of String) from a text file, and then sorting. When I iterate through the list after sorting, it appears to be correctly sorted EXCEPT that the element that was originally at the beginning of the list is now at the end (and it should be somewhere in the middle after the sort)Here is a sample input:
PRE1-PRE2_00015648
PRE1-PRE2_00015649
PRE1-PRE2_00015650
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I have a slightly odd problem that I think is most likely due to an act of foolishness on my part, but for the life of me I (and other members of my team) can't see it.I have an object that contains a generic list property which I would like to sort. I have written a comparer class to do this for me and I am calling it in the following way:baseObject.ListOfThings.Sort(new ThingComparer()I have debugged into my compare function and it is returning the right values.However After the sort call, the list remains unchanged. Have I missed something obvious, or is there something else I need to do.EDIT: Yes I was being a fool, and the property returning a list was recreating it from scratch each time it was accessed
View 4 RepliesI am trying to create a clone function to create a deep copy of an object. I have a very simple class with one property, a List of another custom class. Everything I try keeps ending up with the cloned object being a pointer to the original. I was able to do this in C#, but when I translated the code to VB2010 the copy does not work. My simple class is below.
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I have the following code:
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The intention is to convert an IList of custom objects to a string equivalent comprising each element in the Ilist. Unfortunately I can't seem to find a way to get the underlying data of the custom object, and of course as in the above example, using object simply gives me a string of types definitions, rather than access to the underlying data.
I have two List(Of String) both containing several hundred thousand results.
Private Function AddUniqueFiles(lNewFiles as List(Of String)) As outList(Of String)
Dim aCounter As Integer = 0
Dim files As New inList(Of String)
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However the time it takes to do this comparison can be very long indeed - is there a better way of doing this type of comparison... All I am trying to do is add values from List2 in to List1 which are not already present in List1 - So in effect adding new Unique values found in List 2 in to List 1. I am only looking for performance improvements - nothing else.
I want to create a extension class for the List type so users can do [code]I've it defined as Type and also tried object but neither are accessible when I have a list of strings.If I set it to be string it then appears..But I want something that is more generic and will work with all lists. How do I need to define it?
View 1 RepliesI have a List(of String()). I have written a custom comparer (implements IComparer(of string)) to do an alphanumeric sort.Is there a way to sort the List using a given index to determine which position in the String() to sort by? In other words one time I might sort by Index = 0 and another time by Index = 3. The length of all String() in the list is the same.For reference this question is similar to Sort List<String[]> except I am using VB.net and that question is hardwired to Index=0.
EDIT from OP's comments:I started simple with the non custom comparer but I am getting an error: expression does not produce a value. Not sure what I am doing wrong.Here is the code:
Public Shared Function SortListOfStringArray(ByVal ListOfStringArray As List(Of String()), ByVal SortByIndex As Integer) As List(Of String())
Return ListOfStringArray.Sort(Function(x, y) x(SortByIndex).CompareTo(y(SortByIndex)))
End Function
so I have a generic list in a console application. Dim Channels as New List(Of Chatroom) Chatroom is a structure. But I have multiple classes, threads, and timers looping through this list, sometimes at the same time, but it always seems to raise errors because the number of items in the list gets changed while one of the other classes/threads/timers are looping through also. Is there any way to allow only one to manipulate it at a time?
View 8 RepliesWhats the best way to convert a list(of string) to a string with the values seperated by ,
View 3 RepliesI have a custom list that inherits Generic.List and it has a method for deselecting all of the members named DeselectAll It has looked like this for a few weeks and has worked fine.
Public Sub DeselectAll()
MyBase.ForEach(Function(p As Publipostable) p.ModeEnvoiChoisi = Nothing)
End Sub
Today, it stopped working ?!? I reverted to an earlier version using delegates and that works fine...
Public Sub DeselectAll()
MyBase.ForEach(AddressOf DeselectModeEnvoi)
End Sub
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Edit: Stopped Working meaning it no longer sets the property p.ModeEnvoiChoisi to Nothing on each item in the list. The DeselectAll method gets called, but all the items retain their previous values...
I load a list from a database like the example below. The class has more properties that the database table holds so when I load the list from the DB, there are Null values for certain properties of each item in the list. When I try List = List.Distinct.ToList, it never works (when null values are present).
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I have the following code,
PB.ForEach(Function(x) x.Cost = GetPartCost(x.PartNumber, x.Units, x.Cost, FB))
Return PB.Sum(Function(x) (x.Cost * x.Qty))
However it always returns 0. I've checked and the GetPartCost function executes and returns a non-zero number but the list item cost properties are never updated.The property is just a simple property,
Public Property Cost() As Double
Get
Return _Cost[code]....
If I set a breakpoint in the Set of the property, it never gets hit.
I want to reorder a list of strings into a different list of strings. I am creating multiple loops to do this, however i was wondering if there was a better way to do this.
Dim values As New List(Of String)
For Each val As String In vals
If val.Contains("10") And val.Contains("Year 1") Then
[Code]....
There are going to be quite a lot of these loops to do what I want can anyone offer any help or a better way to go about doing this? Note that I want the values list to return 10,10,10,20,20,20 so that lines that have 10 should be added first and lines with 20 then afterwards.
On my project, If I do String.Contains, Even if its positively true (Made a MsgBox Popup) It returns false! My Code:
Dim bad As Boolean = False
For Each item As String In adlist
If e.Url.Contains(item) Then
[code].....
DB="Source={SQL Server};Server=CALVINRUKA-PCSQLCALVIN;DataSource=DWDSCalTables;Uid=sa;PWD=;Trusted-Connection=Yes;"
I using SQL Server 2008 R2 to connect with HTML page. I trying to connect HTML page with login to SQL Database. I have try called the Source but didnt work.
I am reading a text file and I need to replace a few areas with new text that I marked with {0}, {1}, {2}, {3}, {4}, {5}, {6}. So I load in the text, save it to a string variable, and then use String.Replace but it's not working.
For i As Integer = 0 To 6
fileText.Replace("{" & i & "}", DisplayStudentData(i))
Next[code].....
I put all the data items into an array, then did this after loading the text file:
fileText = String.Format(fileText, dArr(0), dArr(1), dArr(2), dArr(3), dArr(4), dArr(5), dArr(6))
Is this a good way of doing it?