I have converted this existing C# .NET 2.0 code (which appears to take in a string with any characters and return only the numbers in that string):
private static string StripMIN(string min)
{
string result = string.Empty;
int digit = 0;
[code]....
I am getting an error message on line 6 of the VB.Net code at min(i). The error message reads:
"Expression is not an array or a method, and cannot have an argument list"
I have a dictionary that I want to access with a key that is the combination of a string (AcctNum) and a date (BalDate).It seems to me the simplest approach is to create the key by simply converting the date to a string and concatenating:MyKey = BalDate.ToString & "|" & AcctNum
I know I also have the option of creating a composite key by writing a separate class and overriding GetHashCode() and Equals() a la this solution. To me, the concatenated string is a simpler, if somewhat less elegant, solution. Am I missing some compelling reason why I should go with the composite key class approach?
This lookup is the crux of the project I am working on, so performance is my main objective (with readability a close second).
I 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
I have a foxpro table <b> INVENT.DBF</b> linked in MS ACCESS. When I tried to do a search in the table from vb.net application, it is taking a long time. So I want to index the foxpro table and then use it for search.
Here is the sample code I wrote in vb.net <i>
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=D:database.mdb;Persist Security Info=False")
cn.open()
cmd = New OleDbCommand("Create INDEX itmno_idx ON INVENT(ITEM_NO) ", cn)
cmd.ExecuteNonQuery()</i>
But I am getting error "Cannot execute data definition statements on linked data sources"
What needs to be done to index a linked foxpro table using VB.NET.
Right now I'm using the following code in my markup[cod]e...
I would like to be able to call it by index instead of explicitly by "SpeakerName". Is there a way to do this in ASP.NET 4.0?
how do i get the selectedindex/item of a datagridview combobox column?what i want to do is change the back color of datagridcombobox when something is selected from the combobox?So, selecting 'false' will change the color to RED and selecting 'true' changes the color to GREEN.
View 39 RepliesI have a text file that is automatically generated by an older computer system daily. Unfortunately, the columns in this file are not delimited and they are not exactly fixed width (each day the width of each column could change depending on the amount of chars of the data in each column). The file does have column headings, so I want to find the width of each column using the column headings. Here is an example of the column heading row:
JOB_NO[variable amount of white space chars]FILE_NAME[variable amount of ws chars]PROJECT_CODE[variable amount of ws chars][carriage return]
What I want to do is get the index of of the first char in a column and the index of the last white space of a column (from the column heading). I would want to get the index of the "J" in JOB_NUM and the last white space before the "F" in FILE_NAME for the first column.I guess I should also mention that the columns may not always be in the same order from day to day but they will have the same header names. I know I can use the string.indexOf("JOB_NO") to get the index of the start of the column, but how do I get the index of the last white space in each column? (or last whitespace before the next first non-whitespace that denotes the start of the next column)
I have an List(of String), i need to find the index of a particular string in that list. I have searched msdn , but i am confused over the predicate methods. I have never used predicates. This i what i have tried
vb
'on button1 click
Dim Heads As List(Of String) = Me.GetSelectedNodes()
Dim tmp As Integer
[Code].....
I have a string that goes like "abcdefg..."
I would like to find the index where the letter d is at, so I can get the number 3.
I managed to do it by looping through each letter in the string, but that doesn't sound very convenient.
How on specific behaviour can be created in a custom class. I want to be able to create a custom class (a kind of list) where I can access the items by their index (this is the easy part), but also by a string that would describe them. Here is an example:
MyClass(1).SomeProperty = "NewValue"
MyClass("Item1").SomeProperty = "NewValue"
You can see this kind of behaviour in dataset for example where you can select a table by its name or by its index like this :
DataSet.Tables("MyTable").Rows...
DataSet.Tables(1).Rows...
How can I create a custom class that will behave like this?
the following is the my code:
Private Sub cboYear_SelectedIndexChanged(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles cboYear.SelectedIndexChanged
'declare variables
Dim intSelectedYear As Integer
[code]....
I want to replace a char at a specified index of a string.
Short of using the .Remove and .Insert methods I was wondering if there is an easier way.[code]...
i have an array that contains a-z.When i enter text like "ab" into a textbox and click the button, it will search the array and replace the text accordingly to the index number of the array and rewrite into the textbox with the index number.
But what i got from the code below is "ab0 1".May i know how to do so that the textbox will only display the index number and not with the letters. Also, how do i search the array from index 12 onwards to the end of the array.
For Each b As String In TextBox2.Text
If abc.Contains(b) Then
Dim ab As Integer = Array.IndexOf(abc, b)
[code]....
How to search and get position a string in a big file?I have searched in forum2 and get several ways to search for strings in files, but it is not for large files above 500 mb,I have just been make a function to search string and get its index,but it is very slow and uses lots of RAM.This is my function
Function StringInFile(ByRef fs As FileStream, ByRef
substring As String, Optional ByVal occurence As Integer = 1,_
Optional ByVal start As Integer = 0, Optional ByVal count As Integer = -1) As Integer
[code]....
Given an enum similar to this:
Friend Enum TestValue As Int32
tstNotSet = -1
tstA = 0
[code]....
As noted in my comment to Jon Skeet, this construct, along with the rest of the Object's components, executes 100,000 times in a profiling loop in ~570ms (rough average of 3-5 runs).
Exchanging the above construct out with a smaller Array.IndexOf construct loops 100,000 times in ~630ms (again, 3-5 runs, rough average, the whole Object). The new construct looks like this:
Dim p As Int32
p = Array.IndexOf(TestValues, s)
If p <> tstNotSet Then
[Code]....
I am an old VB2 programmer and in the process of moving up. In VB2 I could obtain a data row via and index on an access table. I can not find an example on how to do this. I can retrieve a single row using a query, but an index would be faster. I know in Oracle use can use a hirt to direct the query to use the index.Here is what I was during in VB2 (Sample) with no hint.
Set Stock_Tbl = "DataBaseName".openTable(Stock_Tbl_Name)
Stock_Tbl.Index="Symbol_Idx"
Stock.Tbl.Seek="MSFT"
[code]....
numberofchar = timefull.Length
If timefull = "" Then
Else
If numberofchar = 11 Then
timefull = timefull.Remove(2, 9) ' isolate the hour depends on number of digits in hour parameter
Else
timefull = timefull.Remove(1, 9)
End If
End If
This is my code, it doesn't work when I copy into form load. But when I try it in another form, it works. Index and count must refer to a location within the string. Parameter name: count
why this error happens with a bit of code i was trying? The code is actually intended to be for an onclick event, so it actually works there.
But im just curious as to why it errors as an onchange event. This is 9am pre-caffeine, so the reason is probably starring me in the face! On a form i have a text box, and a combo box. The combo box has various options in it, natch. Its a search form, which then fills a gridview with the results.
Drop down list options are: home number, mobile number, post code, Name, DOB
I thought id try and be "clever" and do away with the need for the combo box. Since a mobile number begins with "07", names are just characters, postcodes are character character number, and home number is all numbers and doesent begin with "07", and date of birth has /'s in it.
So i tried this to test the idea:
Private Sub AppSearchTB_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles AppSearchTB.TextChanged
Dim TLength As Integer = 2
[Code]....
I am trying to get the first 50 letters, so I used the subString function to get it. As you can see, I used this code to get it:
<%# Eval("BannerDescription").ToString.Substring(1, 50)%>
But unfortunately it's not working and an error message is coming up:
Index and length must refer to a location within the string.
Because the user is the one who is controlling the data entry! Some times he gonna enter 10 letters other times maybe 1000 letter?
I tried them all but can we use it this way :
<%# IIf(Eval("BannerDescription").ToString().Length > 49, Eval("BannerDescription").ToString().Substring(0, 49), Eval("BannerDescription"))%>
I have been searching for a while now, but I still can't seem to figure this out. I wrote a rather large program, and to make things more efficient I started to create structs to store more info in a variable.All was well replacing my old code with new code, till I reached a certain point and found that blindly using a loop of integers to access the indexes of the array wouldn't work anymore... I need to access a specific struct by the information contained in a single variable within the struct (like a hashtable key), but can't seem to figure out how.
Is it possible for me to go through my array indexes in a fashion like this?:
Dim myArray(TableCount) As myStruct
Dim TableName As String = "SomeTable"
[code].....
i want index of the first value in a string Without calling IndexOf.
Like, " I am going" and my search value is "am"
so it should give me index value as "2".
I'm trying to copy only the first 15 characters(Including spaces) of a string from TextBox1 to Textbox2If the Text in TextBox1 is:abc1234 jklmnopqrst/uvxyThen the Text in TextBox2 should read as:
View 7 Replieswith the code i made till now found below i'm putting a word in txtEnterMsg and this goes into position 5 of the letters i have in txtLetters. How can i put each letter of the word i write in txtEnterMsg in a different index.eg--if word is 'hello' put 'h' at index 5,'e' at index 13.
View 8 Repliesdt = GetOleDbSchemaTable(OleDb.OleDbSchemaGuid.Indexes...
dt.Rows(i).Item("Index_Name") ==> gives the index name
dt.Rows(i).Item("Column_Name") ==> gives the column name on which we created the index
[code]....
When you need to do random access to the lines of a text file, the regular solution is to put those lines in a list and access them in that list.But doing this if the text file is large creates a large memory overhead and may cause some memory stress on the application.This class maps the file and provide the ability to read any particular line in the file at a random position, without the need to read or put in memory any other line but the desired line. The only memory overhead involve is the 1024 bytes buffer of the base stream.Even if the file mapping can be a process that consume a noticable amount of time if the file is very large ( ~ 5 seconds for each 100,000,000 caracteres) , once the mapping is done the access to a particular line becomes instantaneous regardless of the size of the file. (The file mapping can always be done at a convenient time (ex when the process load) and can be done on a worker thread The class is base on a StreamReader to support the differents Text Encodings Example uf usage ( As I say, if the file is very large, dont do it like that, but declare the class at a convenient time)
Imports Reader = System.IO.MyStreams
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code]....
In my fresh installation of Visual Studio Professional 2005 Visual Basic I have typed this code
dim olddate as date
olddate=datevalue("01-01-2006")
I receive an error: index out of range exception
On an other pc with the same fresh installation this do not happen. Why ? I have tried with other funtions : ctype, cdate but I receive the same error, while on an other pc this code is fine.
trying to determine the index of a child node using the key string so I can add a new child node to it.I am using this code:
vNodesIndex = TreeView1.Nodes.IndexOfKey(Key)
But only works for the root node when I try to find an exiting child node the code returns -1 (Not Found)
I keep getting the error saying that index and length must refer to a location within the string.
Public Class MainForm
Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
Dim description As String = String.Empty
Dim invCount As String = String.Empty
[code]....
I am just learning VB. My problem is the following "Input string was not in a correct format."
Dim fmtStr As String = "{0,-12} {1,10:C2) {2,7:C2}"
lstDisplay.Items.Add(String.Format(fmtStr, "Item", "Quantity", "Price"))
lstDisplay.Items.Add(String.Format(fmtStr, "pizza slices", QP, Pizza))
I get the above message or one that states the following: "Index (zero based) must be greater than or equal to zero and less than the size of the argument list." My teacher is of no help, she tells me to submit the project and she will tell me then. I have submitted a project with the same problem and she told me it worked. I know it didn't. Can someone explain what these messages mean ?
Dim Phone as string = "478-742-4050 478-256-6550"
If _Phone.Length > 25 Then
_Phone = IsNull(ReturnValue.Substring(0, 25).ToString, "")
End If
Return _Phone
Error: "Index and length must refer to a location within the string. Parameter name: length"