Hello I am trying trying to use the contains method to see if a list-block (which exclusively consists of filepaths) 'contains' a certain string. It is supposed to remove the respective entry (in a for loop) if the string is contained in the filepath.
Dim index As Integer = findNumFiles("Archer", 6) '//returns number of files in archer directory
Dim iString As String = "Archer"
For i = 0 To index
If Lookup.Items(index).contains(iString) Then
removeFromList(Lookup, index) '//passes "Lookup" as a ListBlock name and removes the index number
End If
Next
a sample filepath would be
"Z:\Movies and TV\Archer\Season 6\1.mp4"
edit: I forgot to mention that it does not work. I tested the command with a list entry simply named "archer" and if the iString is = to "archer", that list entry is removed. It seems the fact that I'm attempting to use the contains method on a filepath is the problem but I'm not sure.
Thanks for any insight!
Use Instr function to check if the string present or not,
I am not sure about what "Lookup.Items" .
Use 'i'in for loop instead of index
Hope below code will help you
Sub test1()
Dim index As Integer
index = findNumFiles("Archer", 6)
'//returns number of files in archer directory
Dim iString As String
iString = "Archer"
For i = 0 To index
If InStr(1,Lookup.Items(i), iString, 1) > 0 Then
' removeFromList(Lookup, index) '//passes "Lookup" as a ListBlock name and removes the index number
End If
Next
End Sub
Related
First things first, I did a search before posting this question but the answers are so generic that I could not find anything similar to what I'm trying to do. I apologize in advance if this has been answered before and I did not find it.
I have a scenario where I already collected a large list of rows (>10K) from the SQL server and put into an array (List) of strings. These rows are consisted of filenames. Because I already put them on a list, I don't want to query the SQL server again and instead want work with what I already have in memory.
This is the code I'm trying to get right:
'Valid file types for InfoLink1, InfoLink2, InfoLink3
Dim lstValidImageFormats As New List(Of String)({".JPG", ".JPEG", ".JPE", ".BMP", ".PNG", ".TIF", ".TIFF", ".GIF"})
Dim lstValidSTLFormats As New List(Of String)({".STL"})
Dim lstValidSTEPFormats As New List(Of String)({".STP", ".STEP"})
'////////////////
'// Components //
'////////////////
'We don't check Parts.InfoLink because all formats are allowed in this field
'Parts.InfoLink1 - File in Infolink1 columns MUST BE images
For i = 0 To arrStrComponentsInfolink1Values.Count - 1 'We have 10K rows with filenames in this list
For Each FileExtension As String In lstValidImageFormats
If arrStrComponentsInfolink1Values.Item(i).EndsWith(FileExtension) = False Then
End If
Next
Next
I'm trying to parse each item (filename) I have in the array arrStrComponentsInfolink1Values and check if the filename DOES NOT end with one of the extensions in the list lstValidImageFormats. If it doesn't, then I'll send the filename to another list (array).
My difficulty here is about how to iterate through each item in arrStrComponentsInfolink1Values, then check if each filename ends with one of the extensions declared in lstValidImageFormats, do what I want to do with the item if it DOES NOT end with one of those extensions, and then proceed to parse the next item in arrStrComponentsInfolink1Values.
I sincerely don't know what's the best way/performance efficient to do that.
My code above is empty because algorithmically I don't know the best approach to do what I want without querying the SQL server again with something like AND filename NOT LIKE '%.JPG' AND filename NOT LIKE '%.JPEG' AND filename NOT LIKE '%.JPE' AND filename NOT LIKE '%.BMP'...
Because I already have the data in the memory in a list, performance would be much better if I could use what I already have.
Any suggestions or material I could read to learn how to do what I'm looking for?
Thank you!
Here's how I would tackle this:
Dim invalidFormatFiles = _
From x In arrStrComponentsInfolink1Values _
Let fi = New FileInfo(x) _
Where Not lstValidImageFormats.Contains(fi.Extension.ToUpperInvariant()) _
Select x
For Each invalidFormatFile In invalidFormatFiles
' Do your processing
Next
I ended up doing this and it worked:
Dim lstValidImageFormats As New List(Of String)({".JPG", ".JPEG", ".JPE", ".BMP", ".PNG", ".TIF", ".TIFF", ".GIF"})
Dim lstValidSTLFormats As New List(Of String)({".STL"})
Dim lstValidSTEPFormats As New List(Of String)({".STP", ".STEP"})
'////////////////
'// Components //
'////////////////
'We don't check Parts.InfoLink because all formats are allowed in this field
'Parts.InfoLink1 - File in Infolink1 columns MUST BE images
Dim intExtCounter As Integer = 0
For i = 0 To arrIntComponentsInfolink1UNRs.Count - 1 'We have 10K rows with filenames in this list
intExtCounter = 0
For j = 0 To lstValidImageFormats.Count - 1
If arrStrComponentsInfolink1Values.Item(i).EndsWith(lstValidImageFormats.Item(j)) = True Then
intExtCounter += 1
End If
Next
If intExtCounter = 0 Then 'At least one file extension was found
arrIntComponentsInfolink1UNRsReportSectionInvalidExtensions.Add(i) 'File extension is not in the list of allowed extensions
End If
Next
But #41686d6564 answer was the best solution:
Dim newList = arrStrComponentsInfolink1Values.Where(Function(x) Not lstValidImageFormats.Contains(IO.Path.GetExtension(x))).ToList()
Thank you!
I have a list of string containing full file paths and I'd like to apply a function to each path in that list and get the result in the same or a new list.
Dim Remove As New List(Of String)
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Assemblies\045-0201.iam")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\212-D017.ipt")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\211-W01.iam")
Function FileName(spth As String) As String
'Returns filename with extension from full path
Return System.IO.Path.GetFileName(spth)
End Function
The end result I'd like is for the list Remove to contain the following. I know I could use a loop to do this but I've been learning about lambda expressions lately and feel there should be a simple solution to this.
{"045-0201.iam", "212-D017.ipt", "211-W01.iam"}
Try this
Dim Remove As New List(Of String)
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Assemblies\045-0201.iam")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\212-D017.ipt")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\211-W01.iam")
Remove = Remove.Select(Function(s)
Return IO.Path.GetFileName(s)
End Function).ToList
Calling Select and ToList on the existing List is most likely fine and what most people would do. It's worth being aware, though, that that will not modify the existing collection but rather return a new one. If you only have the one reference to that list then that's not a big deal but other references to the existing list will not see the change, e.g.
Dim fileNames As New List(Of String) From {"C:\Folder\File1.ext",
"C:\Folder\File2.ext",
"C:\Folder\File3.ext"}
Dim temp = fileNames
fileNames = fileNames.Select(Function(s) Path.GetFileName(s)).ToList()
For Each fileName In fileNames
Console.WriteLine(fileName)
Next
For Each fileName In temp
Console.WriteLine(fileName)
Next
If you run that then you'll see that the first loop displays just the files names but the second loop displays the full paths, because it still refers to the original list.
If that's a problem, there is another way to do this without an explicit loop:
Dim fileNames As New List(Of String) From {"C:\Folder\File1.ext",
"C:\Folder\File2.ext",
"C:\Folder\File3.ext"}
Dim temp = fileNames
Array.ForEach(Enumerable.Range(0, fileNames.Count).ToArray(),
Sub(i) fileNames(i) = Path.GetFileName(fileNames(i)))
For Each fileName In fileNames
Console.WriteLine(fileName)
Next
For Each fileName In temp
Console.WriteLine(fileName)
Next
If you run that then you'll see that both loops display just the file names because there's only one list.
That said, if the first code posed a problem because of multiple references to the list, I'd just use a loop.
I know you stated that you'd want something other than a loop, but there really is no needfor anything fancy here. By the way, writing Remove.Add sounds like a riddle.
Sub Main()
Dim Remove As New List(Of String)
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Assemblies\045-0201.iam")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\212-D017.ipt")
Remove.Add("C:\_Vault\Designs\Jobs\Customer\Job23\Parts\211-W01.iam")
Console.WriteLine("Before execution")
For Each s As String In Remove
Console.WriteLine(s)
Next
For i As Integer = 0 To Remove.Count - 1
Remove(i) = MyFunction(Remove(i))
Next
Console.WriteLine("After execution")
For Each s As String In Remove
Console.WriteLine(s)
Next
Console.ReadLine()
End Sub
Private Function MyFunction(path As String) As String
Return IO.Path.GetFileName(path)
End Function
This outputs:
I have a question which asks me to calculate something from an input file. The problem is, the lines in the file don't use any special character as delimiter, like , or |. I will show it down below.
Data Communication
20
Visual Basic
40
The output I need to write to another file should look like this:
Data communication 20
Visual Basic 40
Total Books : 60
The problem is, how can I specify the delimiter? Like when there is a symbol as in strArray = strLine.Split(","). Since there is nothing I can use as delimiter, how can I split the file content?
There's no real need to split the text in the input file, when you can read a file line by line using standard methods.
You can use, e.g., a StreamReader to read the lines from the source file, check whether the current line is just text or it can be converted to a number, using Integer.TryParse and excluding empty lines.
Here, when the line read is not numeric, it's added as a Key in a Dictionary(Of String, Integer), unless it already exists (to handle duplicate categories in the source file).
If the line represents a number, it's added to the Value corresponding to the category Key previously read, stored in a variable named previousLine.
This setup can handle initial empty lines, empty lines in the text body and duplicate categories, e.g.,
Data Communication
20
Visual Basic
40
C#
100
Visual Basic
10
Other stuff
2
C++
10000
Other stuff
1
If a number is instead found in the first line, it's treated as a category.
Add any other check to handle a different structure of the input file.
Imports System.IO
Imports System.Linq
Dim basePath = "[Path where the input file is stored]"
Dim booksDict = New Dictionary(Of String, Integer)
Dim currentValue As Integer = 0
Dim previousLine As String = String.Empty
Using sr As New StreamReader(Path.Combine(basePath, "Books.txt"))
While sr.Peek > -1
Dim line = sr.ReadLine().Trim()
If Not String.IsNullOrEmpty(line) Then
If Integer.TryParse(line, currentValue) AndAlso (Not String.IsNullOrEmpty(previousLine)) Then
booksDict(previousLine) += currentValue
Else
If Not booksDict.ContainsKey(line) Then
booksDict.Add(line, 0)
End If
End If
End If
previousLine = line
End While
End Using
Now, you have a Dictionary where the Keys represent categories and the related Value is the sum of all books in that category.
You can Select() each KeyValuePair of the Dictionary and transform it into a string that represents the Key and its Value (Category:Number).
Here, also OrderBy() is used, to order the categories alphabetically, in ascending order; it may be useful.
File.WriteAllLines is then called to store the strings generated.
In the end, a new string is appended to the file, using File.AppendAllText, to write the sum of all books in all categories. The Sum() method sums all the Values in the Dictionary.
Dim newFilePath = Path.Combine(basePath, "BooksNew.txt")
File.WriteAllLines(newFilePath, booksDict.
Select(Function(kvp) $"{kvp.Key}:{kvp.Value}").OrderBy(Function(s) s))
File.AppendAllText(newFilePath, vbCrLf & "Total Books: " & booksDict.Sum(Function(kvp) kvp.Value).ToString())
The output is:
C#:100
C++:10000
Data Communication:20
Other stuff:3
Visual Basic:50
Total Books: 10173
Sure.. System.IO.File.ReadAllLines() will read the whole file and split into an array based on newlines, so you'll get an array of 4 elements. You can process it with a flipflop boolean to get alternate lines, or you can try and parse the line to a number and if it works, then its a number and if not, it's a string. If it's a number take the string you remembered (using a variable) from the previous loop
Dim arr = File.ReadALlLines(...)
Dim isStr = True
Dim prevString = ""
For Each s as String in arr
If isStr Then
prevString = s
Else
Console.WriteLine($"The string is {prevString} and the number is {s}")
End If
'flip the boolean
isStr = Not isStr
Next s
I used File.ReadAllLines to get an array containing each line in the file. Since the size of the file could be larger than the sample shown, I am using a StringBuilder. This save having to throw away and create a new string on each iteration of the loop.
I am using interpolated strings indicated by the $ preceding the quotes. This allows you to insert variables into the string surrounded by braces.
Note the Step 2 in the For loop. i will increment by 2 instead of the default 1.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim lines = File.ReadAllLines("input.txt")
Dim sb As New StringBuilder
Dim total As Integer
For i = 0 To lines.Length - 2 Step 2
sb.AppendLine($"{lines(i)} {lines(i + 1)}")
total += CInt(lines(i + 1))
Next
sb.AppendLine($"Total Books: {total}")
TextBox1.Text = sb.ToString
End Sub
I have a csv file I need to parse and get an item out of the middle of it. I have chose string manipulation to do this.
sample input file data would be..
Nick,frog,snake,1234
I can get the last entry "1234" with this code..
line.Substring(line.LastIndexOf(",") + 1)
How would I get the 3rd entry, "snake", with substrings? (what the OP means is: how can I get the third element in the comma-separated string, which happens to be "snake")
If you've stored the text of your file in myInputText, and you want to access the third item, the following will work:
resultString = Strings.Split(myInputText, ",")(2)
You can access any string in the file this way.
How would I get the 3rd entry "snake" with substrings?
The easiest way would obviously be with split:
Dim teststr As String = "Nick,frog,snake,1234"
Dim teststr2 As String = teststr.Split(","c)(2)
A simple function like this, using substring, will do the same thing:
Dim teststr3 As String = GetStr(teststr, 2)
Private Function GetStr(input As String, index As Integer) As String
input += ","
Dim counter As Integer = 0
If index <> 0 Then
Do
input = input.Substring(input.IndexOf(","c)).TrimStart(","c)
counter += 1
Loop Until counter = index
End If
GetStr = input.Substring(0, input.IndexOf(","c))
End Function
I am using Visual Studio.net, Visual Basic and I have a question.
If I have a string that has many lines in it, what is the best way to get the contents of a certain line?
E.g If the string is as follows:
Public Property TestProperty1 As String
Get
Return _Name
End Get
Set(value As String)
_Name = value
End Set
End Property
What is the best way to get the contents of line 2 ("Get")?
The simplest is to use ElementAtOrdefault since you don't need to check if the collection has so many items. It would return Nothing then:
Dim lines = text.Split({Environment.NewLine}, StringSplitOptions.None)
Dim secondLine = lines.ElementAtOrDefault(1) ' returns Nothing when there are less than two lines
Note that an index is zero-based, hence i have used ElementAtOrDefault(1) to get the second line.
This is the non-linq approach:
Dim secondLine = If(lines.Length >= 2, lines(1), Nothing) ' returns Nothing when there are less than two lines
That depends on what you mean by "best".
The easiest, but least efficient, is to split the string into lines and get one of them:
Dim second As String = text.Split(Environment.NewLine)(1)
The most efficient would be to locate the line breaks in the string and get the line using Substring, but takes a bit more code:
Dim breakLen As Integer = Environment.Newline.Length;
Dim firstBreak As Integer = text.IndexOf(Environment.Newline);
Dim secondBreak As Integer = text.IndexOf(Environment.NewLine, firstBreak + breakLen)
Dim second As String = text.Substring(firstBreak + breakLen, secondBreak - firstBreak - breakLen)
To get any line, and not just the second, you need even more code to loop through the lines until you get to the right one.