I have a text file with records of machines stored on it, a single record looks like this:
"1234567890","12/04/2013","Saw","Hilti","17/11/2012",#TRUE#,#FALSE#,#FALSE#,"Made odd noise when operating"
What I would like to achieve is to populate a combo box with only the first item of each record - the serial number - so as to be able to search for the machine in a form based on the selected serial number. I need it to read the file, pick out the serial number from each record, fill the combo box with them, then allow you to select the one that you want.
Thanks in advance for any help.
if you are using a CSV formatted text file you can store info in a datatable and store each datarow in your cb, and use the DisplayMember property of the combobox to show only the first column. You also need that first line has the names of the columns to achieve this.
Try this supposing the first column is called Serial:
For Each r as DataRow in table.Rows
combobox1.Items.Add(r)
Next
combobox1.DisplayMember("Serial")
If not, you can still use your streamreader to obtain each line and split it to obtain first field.
Try:
Do
Dim line As String = reader.readLine()
If line Is Nothing Then Exit Do
Dim fields as String() = Split(line, ",")
combobox1.Items.Add(fields(0))
Loop
Hope it helps. You may have to use SubString method to retire the quotes. I post it apart:
replace
combobox1.Items.Add(fields(0))
by
combobox1.Items.Add(fields(0).SubString(1,fields(0).length -1))
If it's a simple app and you're happy to use the reader mentioned above, you can also do the following. I've used Replace() instead of Substring().
Dim reader As StreamReader = New StreamReader(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), "yourFile.txt"))
Dim input = "", fields() As String
While (Not reader.EndOfStream)
input = reader.ReadLine()
fields = input.Split(",")
Dim itemToAdd = fields(0).Replace("""", "")
ComboBox.Items.Add(itemToAdd)
End While
Related
I have a text file which contains the same string of characters in different lines. I read the file using this code:
Dim readTexte() As String = File.ReadAllLines(OuvrirFichier, Encoding.UTF8)
Dim t As String
For Each t In readTexte
If t.Contains(TreeView1.SelectedNode.Text) Then
TextBox2.Text = Trim(t.Substring(0, 18))
TextBox1.Text = Trim(t.Substring(18, 90))
TextBox4.Text = Trim(t.Substring(107, 120))
End If
Next
However, I have a problem because when cutting and reading these strings. The code is not able to choose the right line to match the TreeView node, because it identifies several equally perfect strings.
For example, the first line contains 3 substrings (fixed width fields):
Saint, Augustine, and Doctor of the Church.
The second line contains three sub-strings as well, slightly different:
Saint, Monica, and mother of Saint Augustine
When I want to read, my code gives me two Augustines, and mixes Augustine and Monique! The TextBox2 contains the string contained in the treeview.
How can I fix this?
The treeview is created as simply as possible, thus:
Dim readText () As String = File.ReadAllLines (OpenFile,
Encoding.UTF8)
Dim s As String
For Each s In readText
TextBox2.Text = Trim (s.Substring (0, 18))
TextBox1.Text = Trim (s.Substring (18, 90))
TextBox4.Text = Trim (s.Substring (107, 120))
Dim node As TreeNode = Me.TreeView1.Nodes (0)
TreeView1.Nodes (0) .Nodes.Add (New TreeNode (TextBox1.Text))
Next
We need to know more about how the TreeView is built before we can answer this. It's possible there is simply not enough data associated with the TreeView right now, and the solution will be in a completely different area of the code.
However, I can provide some notes. First, reading a file is one of the slowest things possible to do in a computer. We already see this is small enough to fit in memory; if it's also reasonably stable (doesn't change often), you can save significant work by loading to the array once when the program starts.
Next, I wouldn't keep just a simple array of strings. Instead, I'd parse the data into separate fields right at load. A Tuple, Class, or even string array can all work.
Finally, this code will continue looping even after if finds a match. I'd have a way to stop once we find what we're looking for.
Put it all together like this:
'Create a set of Tuples. Could also use a class here.
Dim readTexte() As IEnumerable(Of (String, String, String)) =
File.ReadLines(OuvrirFichier, Encoding.UTF8).
Select(Function(line) (Trim(line.SubString(0, 18)), Trim(line.SubString(18,90)), Trim(line.SubString(107,120))) )
'Search the collection for the first match
Dim result = readTexte.First(Function(record) TreeView1.SelectedNode.Text.Equals(record.Item1))
TextBox2.Text = result.Item1
TextBox1.Text = result.Item2
TextBox4.Text = result.Item3
Again, this doesn't solve your matching problem, because the question doesn't contain the information we need to help do that. Please edit the question to include more details on how the TreeView is created.
First, I am not a programmer, I mainly just do simple scripts however there are somethings that are just easier to do in VB, I am pretty much self taught so forgive me if this sounds basic or if I can't explain it to well.
I have run into an issue trying to load a multi-column text file into a list box. There are two separate issues.
First issue is to read the text file and only grab the first column to use in the listbox, I am currently using ReadAllLines to copy the text file to a string first.
Dim RDPItems() As String = IO.File.ReadAllLines(MyDocsDir & "\RDPservers.txt")
However I am having a difficult time finding the correct code to only grab the first Column of this string to put in the listbox, if I use the split option I get an error that "Value of type '1-dimensional array of String' cannot be converted to 'String'"
The code looked like
frmRDP.lstRDP.Items.Add() = Split(RDPItems, ";", CompareMethod.Text)
This is the first hurdle, the second issue is what I want to do is if an item is selected from the List box, the value of the second column gets pulled into a variable to use.
This part I'm not even sure where to begin.
Example data of the text file
Server1 ; 10.1.1.1:3389
Server2 ; 192.168.1.1:8080
Server3 ; 172.16.0.1:9833
.....
When it's working the application will read a text file with a list of servers and their IPs and put the servers in a listbox, when you select the server from the listbox it and click a connect button it will then launch
c:\windows\system32\mstsc.exe /v:serverip
Any help would be appreciated, as I can hard code a large list of this into the VB application it would be easier to just have a text file with a list of servers and IPs to load instead.
The best practise for this would probably be to store your "columns" in a Dictionary. Declare this at class level (that is, outside any Sub or Function):
Dim Servers As New Dictionary(Of String, String)
When you load your items you read the file line-by-line, adding the items to the Dictionary and the ListBox at the same time:
Using Reader As New IO.StreamReader(IO.Path.Combine(MyDocsDir, "RDPservers.txt")) 'Open the file.
While Reader.EndOfStream = False 'Loop until the StreamReader has read the whole file.
Dim Line As String = Reader.ReadLine() 'Read a line.
Dim LineParts() As String = Line.Split(New String() {" ; "}, StringSplitOptions.None) 'Split the line into two parts.
Servers.Add(LineParts(0), LineParts(1)) 'Add them to the Dictionary. LineParts(0) is the name, LineParts(1) is the IP-address.
lstRDP.Items.Add(LineParts(0)) 'Add the name to the ListBox.
End While
End Using 'Dispose the StreamReader.
(Note that I used IO.Path.Combine() instead of simply concatenating the strings. I recommend using that instead for joining paths together)
Now, whenever you want to get the IP-address from the selected item you can just do for example:
Dim IP As String = Servers(lstRDP.SelectedItem.ToString())
Hope this helps!
EDIT:
Missed that you wanted to start a process with it... But it's like charliefox2 wrote:
Process.Start("c:\windows\system32\mstsc.exe", "/v:" & Servers(lstRDP.SelectedItem.ToString()))
Edit: #Visual Vincent's answer is way cleaner. I'll leave mine, but I recommend using his solution instead. That said, scroll down a little for how to open the server. He's got that too! Upvote his answer, and mark it as correct!
It looks like you're trying to split an array. Also, ListBox.Items.Add() works a bit differently than the way you've written your code. Let's take a look.
ListBox.Items.Add() requires that you provide it with a string inside the parameters. So you would do it like this:
frmRDP.lstRDP.Items.Add(Split(RDPItems, ";", CompareMethod.Text))
But don't do that!
When you call Split(), you must supply it with a string, not an array. In this case, RDPItems is an array, so we can't split the entire thing at once. This is the source of the error you were getting. Instead, we'll have to do it one item at a time. For this, we can use a For Each loop. See here for more info if you're not familiar with the concept.
A For Each loop will execute a block of code for each item in a collection. Using this, we get:
For Each item In RDPItems
Dim splitline() As String = Split(item, ";") 'splits the item by semicolon, and puts each portion into the array
frmRDP.lstRDP.Items.Add(splitline(0)) 'adds the first item in the array
Next
OK, so that gets us our server list put in our ListBox. But now, we want to open the server that our user has selected. To do that, we'll need an event handler (to know when the user has double clicked something), we'll have to find out which server they selected, and then we'll have to open that server.
We'll start by handling the double click by creating a sub to deal with it:
Private Sub lstRDP_MouseDoubleClick(sender As Object, e As MouseEventArgs) Handles lstRDP.MouseDoubleClick
Next, we'll get what the user has selected. Here, we're setting selection equal to the index that the user has selected (in this case, the first item is 0, the second is 1, and so on).
Dim selection As Integer = lstRDP.SelectedIndex
Lastly, we need to open the server. I'm assuming you want to do that in windows explorer, but if I'm mistaken please let me know.
Dim splitline() As String = Split(RDPItems(selection), ";")
Dim location As String = Trim(splitline(1))
We'll need to split the string again, but you'll notice this time I'm choosing the item whose location in the array is the same as the index of the list box the user has selected. Since we added our items to our listbox in the order they were added to our array, the first item in our listbox will be the first in the array, and so on. The location of the server will be the second part of the split function, or splitline(1). I've also included the Trim() function, which will remove any leading or trailing spaces.
Finally, we need to connect to our server. We'll use Process.Start() to launch the process.
Process.Start("c:\windows\system32\mstsc.exe", "/v:" & location)
For future reference, to first argument for Process.Start() is the location of the process, and the second argument is any argument the process might take (in this case, what to connect to).
Our final double click event handler looks something like this:
Private Sub lstRDP_MouseDoubleClick(sender As Object, e As MouseEventArgs) Handles lstRDP.MouseDoubleClick
Dim selection As Integer = lstRDP.SelectedIndex
Dim splitline() As String = Split(RDPItems(selection), ";")
Dim location As String = Trim(splitline(1))
Process.Start("c:\windows\system32\mstsc.exe", "/v:" & location)
End Sub
A final note: You may need to put
Dim RDPItems() As String = IO.File.ReadAllLines(MyDocsDir & "\RDPservers.txt")
outside of a sub, and instead just inside your class. This will ensure that both the click handler and your other sub where you populate the list box can both read from it.
Probably kick-self simple, but this is defeating me.
I have a text file which I am looking to grab in sections and populates separate text boxes. This is what the list looks like:
data_file_name
<1st section>
data
data
data
<2nd section>
data
data
data
etc.
Is there a way for me to take each section? I thought of changing the delimiter in a TextReader but some of the data also has the <> signs in it.
One way is to use system.io.file.readalllines(path) to read the file into a string array. Then process the array in memory sequentially, or using indexof, for "<1st section>", etc. This one approach of about a dozen that will work equally well.
Below is code to read each line of the file into a string. Then, you compare the string value to see if it looks like a new section. If so, do your new section code, else to your current section code
Dim reader as new streamreader(file.txt)
Dim inline as String
While reader.peek <> -1
inline = reader.readline
if inline.startswith("<") and inline.endswith(">") and inline.contains("section")
'do new section routine
else
'do current section routine
end if
end while
reader.close
I have a program I am creating and when i go to remove blank lines this is how I go about it.
For Each i As ListViewItem In lvSongs.SelectedItems
lvSongs.Items.Remove(i)
CurrentSong = i.SubItems(4).Text 'This is the Songs Path
files = File.ReadAllText("songs.txt") 'The songs path's are in the txt
'I am using this as a list of lines i want to keep in
'the txt file.
Dim linesToKeep As New List(Of String)
For Each line As String In files 'Goes through lines
If Not line.Contains(CurrentSong) Then 'checks to see if line is Current song
linesToKeep.Add(line) 'Adds line if its not CurrentSong to the list
End If
Next
File.WriteAllLines("songs.txt", linesToKeep.ToArray())
but when i go to check the txt document, i get this:
EXAMPLE (but written horizontally, each letter being on a new line)
in the text file my friend says its because i have lines set as a string instead of a string().
Thanks for anyhelp!
Ask for more information if im confusing you...
The problem is you are using the ReadAllText API. This returns a String not a String() hence when you later iterate you are iterating over every character in the file, not every line. To fix this use the ReadAllLines API which returns a String()
files = File.ReadAllLines("songs.txt")
Note I can't tell if files is an implicitly declared local or a field. If it's a field typed to String you will need to change the type to String().
I need your help, guys! :|
I've got myself a CSV file with the following contents:
1,The Compact,1.8GHz,1024MB,160GB,440
2,The Medium,2.4GHz,1024MB,180GB,500
3,The Workhorse,2.4GHz,2048MB,220GB,650
It's a list of computer systems, basically, that the user can purchase.
I need to read this file, line-by-line, into an array. Let's call this array csvline().
The first line of the text file would stored in csvline(0). Line two would be stored in csvline(1). And so on. (I've started with zero because that's where VB starts its arrays). A drop-down list would then enable the user to select 1, 2 or 3 (or however many lines/systems are stored in the file). Upon selecting a number - say, 1 - csvline(0) would be displayed inside a textbox (textbox1, let's say). If 2 was selected, csvline(1) would be displayed, and so on.
It's not the formatting I need help with, though; that's the easy part. I just need someone to help teach me how to read a CSV file line-by-line, putting each line into a string array - csvlines(count) - then increment count by one so that the next line is read into another slot.
So far, I've been able to paste the numbers of each system into an combobox:
Using csvfileparser As New Microsoft.VisualBasic.FileIO.TextFieldParser _
("F:\folder\programname\programname\bin\Debug\systems.csv")
Dim csvalue As String()
csvfileparser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
csvfileparser.Delimiters = New String() {","}
While Not csvfileparser.EndOfData
csvalue = csvfileparser.ReadFields()
combobox1.Items.Add(String.Format("{1}{0}", _
Environment.NewLine, _
csvalue(0)))
End While
End Using
But this only selects individual values. I need to figure out how selecting one of these numbers in the combobox can trigger textbox1 to be appended with just that line (I can handle the formatting, using the string.format stuff). If I try to do this using csvalue = csvtranslator.ReadLine , I get the following error message:
"Error 1 Value of type 'String' cannot be converted to '1-dimensional array of String'."
If I then put it as an array, ie: csvalue() = csvtranslator.ReadLine , I then get a different error message:
"Error 1 Number of indices is less than the number of dimensions of the indexed array."
What's the knack, guys? I've spent hours trying to figure this out.
Please go easy on me - and keep any responses ultra-simple for my newbie brain - I'm very new to all this programming malarkey and just starting out! :)
Structure systemstructure
Dim number As Byte
Dim name As String
Dim procspeed As String
Dim ram As String
Dim harddrive As String
Dim price As Integer
End Structure
Private Sub csvmanagement()
Dim systemspecs As New systemstructure
Using csvparser As New FileIO.TextFieldParser _
("F:\folder\programname\programname\bin\Debug\systems.csv")
Dim csvalue As String()
csvparser.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
csvparser.Delimiters = New String() {","}
csvalue = csvparser.ReadFields()
systemspecs.number = csvalue(0)
systemspecs.name = csvalue(1)
systemspecs.procspeed = csvalue(2)
systemspecs.ram = csvalue(3)
systemspecs.harddrive = csvalue(4)
systemspecs.optical = csvalue(5)
systemspecs.graphics = csvalue(6)
systemspecs.audio = csvalue(7)
systemspecs.monitor = csvalue(8)
systemspecs.software = csvalue(9)
systemspecs.price = csvalue(10)
While Not csvparser.EndOfData
csvalue = csvparser.ReadFields()
systemlist.Items.Add(systemspecs)
End While
End Using
End Sub
Edit:
Thanks for your help guys, I've managed to solve the problem now.
It was merely a matter calling loops at the right point in time.
I would recommend using FileHelpers to do the reading.
The binding shouldn't be an issue after that.
Here is the Quickstart for Delimited Records:
Dim engine As New FileHelperEngine(GetType( Customer))
// To Read Use:
Dim res As Customer() = DirectCast(engine.ReadFile("FileIn.txt"), Customer())
// To Write Use:
engine.WriteFile("FileOut.txt", res)
When you get the file read, put it into a normal class and just bind to the class or use the list of items you have to do custom stuff with the combobox. Basically, get it out of the file and into a real class asap, then things will be easier.
At least take a look at the library. After using it, we use a lot more simple flat files since it is so easy, and we haven't written a file access routine since (for that kinda stuff).
http://msdn.microsoft.com/en-us/library/microsoft.visualbasic.fileio.textfieldparser.aspx
I think your main problem is understanding how arrays work (hence the error message).
You can use split and join functions to convert strings into and out of arrays
dim s() as string = split("1,2,3",",") gives and array of strings with 3 elements
dim ss as string = join(s,",") gives you the string back
Firstly, it's actually really good that you are using the TextFieldParser for reading CSV files - most don't but you won't have to worry about extra commas and quoted text etc...
The Readline method only gives you the raw string, hence the "Error 1 Value of type 'String' cannot be converted to '1-dimensional array of String'."
What you may find easier with combo boxes etc is to use an object (e.g. 'systemspecs') rather than strings. Assign the CSV data to the objects and override the "ToString" method of the 'systemspecs' class to display in the combo box how you want with formatting etc. That way when you handle the SelectedIndexChanged event (or similar) you get the "SelectedItem" from the combo box (which can be Nothing so check) and cast it as the 'systemspecs' to use it. The advantage is that you are not restricted to display the exact data in the combo etc.
' in "systemspecs"...
Public Overrides Function ToString() As String
Return Name ' or whatever...
End Function ' ToString
e.g.
dim item as new systemspecs
item.ID = csvalue(1)
item.Name = csvalue(2)
' etc...
combobox1.Items.Add(item)
Let me know if that makes sense!
PK :-)