I have a string output from user interface as below,
strFormula ="gridControlName.Rows(i).cells("C1").value *
gridControlName.Rows(i).cells("C2").value"
if i write code like
dblRes=gridControlName.Rows(i).cells("C1").value *
gridControlName.Rows(i).cells("C2").value
it will give result.. but since its a string i could not get result
How can I remove the double quotes from the above string and get the values entered in the grid cells to be multiplied?
I don't think there's an 'easy' way to do this, since VB.Net doesn't have an "eval()" like some other languages. However, it does support run-time compilation. Here are a couple articles which may help you:
Using .NET Languages to make your Application Scriptable (VB.Net example)
Runtime Compilation (A .NET eval statement) (C# example)
Both are intended to be a bit more robust than just executing single lines of code, allowing users to input entire textboxes of their own code for example, but should give you some direction. Both include sample projects.
Hi guys thanks for your updates.. I wrote my own function by using your concepts and some other code snippets .I am posting the result
Function generate(ByVal alg As String, ByVal intRow As Integer) As String Dim algSplit As String() = alg.Split(" "c)
For index As Int32 = 0 To algSplit.Length - 1
'algSplit(index) = algSplit(index).Replace("#"c, "Number")
If algSplit(index).Contains("[") Then
Dim i As Integer = algSplit(index).IndexOf("[")
Dim f As String = algSplit(index).Substring(i + 1, algSplit(index).IndexOf("]", i + 1) - i - 1)
Dim grdCell As Infragistics.Win.UltraWinGrid.UltraGridCell = dgExcelEstimate.Rows(intRow).Cells(f)
Dim dblVal As Double = grdCell.Value
algSplit(index) = dblVal
End If
Next
Dim result As String = String.Join("", algSplit)
'Dim dblRes As Double = Convert.ToDouble(result)
Return result
End Function
Thanks again every one.. expecting same in future
Related
I'm using Visual studio to build a small utility.
I'm importing variables from a text file (this makes my program expandable in the future).
I'm running into a road block trying to split the variables into usable parts.
The text file is set up as such:
Game1:flshflhdlsfsdsfs
Game2:ugdjgndrgbdvdnjd
Game3:gnnereknengievke
And the code I've gathered from searching around trying to understand how I could do this is (It's gone through multiple rewrites but I feel this is probably the closest I've gotten):
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
When I run a test like this, I get an error that String_before cannot be converted to an object. I tried switching "Dim string_before As String = value.Substring(0, x - 2)" to Dim string_before As Object = value.Substring(0, x - 2), but the dropdown that's supposed to be populated by at least one of the entries before the : has absolutely nothing in it.
Being pretty new at VB and feeling like I've exhausted pretty much every way I could think of searching in google and trying to piece together various bits of information, I figure I'd try asking my own direct question:
How would I go about reading all the lines from a text file, then splitting before the : to fill a combobox, and using a label to display the string after the : matching which ever entry is selected in the dropdown.
Thanks in advance for any help.
EDIT with full code:
Imports System.IO
Public Class Saves_frm
Private Sub Saves_frm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim value As String = File.ReadAllText("Games.txt")
Dim cut_at As String = ":"
Dim x As Integer = InStr(value, cut_at)
Dim string_before As String = value.Substring(0, x - 2)
Dim string_after As String = value.Substring(x + cut_at.Length - 1)
Games_drp.Items.AddRange(string_before)
End Sub
End Class
When run as is, I get an error that 'string_before' can't be converted from a string to an object, but when I make the following change from:
Dim string_before As String = value.Substring(0, x - 2)
to:
Dim string_before As Object = value.Substring(0, x - 2)
The error goes away, but the dropdown remains blank.
It's easier to use File.ReadAllLines, as it returns an array with all the file's lines. Then, you can loop through the lines, splitting each line and adding the result to the ListBox. This should be an example, but feel free to correct any mistakes I made, as I wrote it on my phone and it's been a long time since I used VB.
Dim lines() As String = File.ReadAllLines("file.txt")
For Each line As String In lines
Dim split() As String = line.Split(":"c)
gDic.Add(split(0), split(1))
Next
EDIT: Then, you most certainly want a dictionary that contains the name and the data, check the updated code.
Then, add the names by looping through gDic.Keys. When a name is selected, access its value with gDic("key").
.. eg: have a stri ng
strResult="controlName1.value * controlName2.value"
.. I need to change it to just controlName1.value * controlName2.value so that i can get the output as double value
Please reply
Thanks
If you're using Windows Forms, there is an indexer property that accepts the name of a sub-control as a string and returns the control if a match is found. See: Control.ControlCollection.Item Property (String).aspx
The straightforward alternative in all UI frameworks is to map Strings to Controls like such:
Function MapStringToControl(ctlName As String) As Control
Select Case ctlName
Case "controlName1"
Return controlName1
Case "controlName2"
Return controlName2
Case Else
Return Nothing
End Function
Of course note that there is no .Value property in Windows Forms--you need to do something like Integer.Parse(ctl.Text).
It depends what type of control it is. For example a textbox has a .Text property. A NumericUpDown control has a .Value property.
All you need to do is to convert the appropriate property to the appropriate type. So for TextBoxes:
Dim result as Double = CDbl(txtFoo.Text) * CDbl(txtBar.Text)
For a NumericUpDown:
Dim result as Double = CDbl(nudFoo.Value) * CDbl(numBar.Value)
Hi guys thanks for your updates.. I wrote my own function by using your concepts and some other code snippets .I am posting the result
Function generate(ByVal alg As String, ByVal intRow As Integer) As String
Dim algSplit As String() = alg.Split(" "c)
For index As Int32 = 0 To algSplit.Length - 1
'algSplit(index) = algSplit(index).Replace("#"c, "Number")
If algSplit(index).Contains("[") Then
Dim i As Integer = algSplit(index).IndexOf("[")
Dim f As String = algSplit(index).Substring(i + 1, algSplit(index).IndexOf("]", i + 1) - i - 1)
Dim grdCell As Infragistics.Win.UltraWinGrid.UltraGridCell = dgExcelEstimate.Rows(intRow).Cells(f)
Dim dblVal As Double = grdCell.Value
algSplit(index) = dblVal
End If
Next
Dim result As String = String.Join("", algSplit)
'Dim dblRes As Double = Convert.ToDouble(result)
Return result
End Function
Thanks again every one.. expecting same in future
i have a database in one field like below 222-225. I try to make split to read that value for my function. Just simple function a=225 b=222 then total=(a-b)+1. here my code
Dgv.CellClick
'Dim x As Boolean
Dim a As Double
Dim total As Double
a = CDbl(Dgv.Item(8, Dgv.CurrentRow.Index).Value)
Split(a, "-")
total = (a) - (a)
Dgv.Item(9, Dgv.CurrentRow.Index).Value = total
My problem is this doesn't work. I can't get the value that I split. Any idea how to solve this problem?
note: I use VB.NET 2005
If you want total=(a-b)+1 .. That should be
dim b = a.Split("-")
total = val(b(1)) - val(b(2)) + 1
may be this can help. try this...
Dim a As String
a = ""
Dim x As String
Dim total As Double
a = Dgv.Item(8, Dgv.CurrentRow.Index).Value.ToString
Dim ary() As String
x = a
ary = x.Split("-")
total = CInt(ary(1)) - CInt(ary(0))
Dgv.Item(9, Dgv.CurrentRow.Index).Value = total
Like others have said, Split() returns a String array, like this:
Dim SplitValue() As String = Split(a, "-")
total = (CType(SplitValue(1), Double) - CType(SplitValue(0), Double)) + 1
If I read your question correctly, the value you're looking for is 222-225, and that value is located in the specified cell of Dgv (which I'm guessing is a DataGridView). If my understanding is correct, there are a couple of things going on.
First, I'm not sure why you're trying to convert that value to a double with the following line of code:
a = CDbl(Dgv.Item(8, Dgv.CurrentRow.Index).Value)
The Item property of a DataGridView holds a DataGridViewCell, and the Value property of the DataGridViewCell returns an Object. Trying to convert 222-225 to a double will, I believe, fail (though since this is VB.NET, it's possible it won't depending on the options you set - I'm not as familiar with VB.NET as I am with C#).
Even if it does successfully work (I'm not sure what the output would be), Split expects a string. I would change that line of code to the following:
a = Dgv.Item(8, Dgv.CurrentRow.Index).Value.ToString()
Now you have a string that you can use Split on. The Split you have in your posted code appears to be the Visual Basic (pre-.NET) Split method Split Function (Visual Basic). As others have mentioned, Split returns an array of strings based on the delimiter. In your code, you don't assign the result of Split to anything, so you have no way to get the values.
I would recommend using the .NET version of Split (String.Split Method) - there are several ways you can call String.Split, but for purposes of your code I'd use it like this:
Dim splits As String() = a.Split(New Char() { "-" })
Where a is the string value from the selected DataGridViewCell above. This will give you a 2-element array:
splits(0) = "222"
splits(1) = "225"
The final part is your formula. Since you have strings, you'll need to convert them to a numeric data type:
total = (CDbl(splits(1)) - CDbl(splits(0))) + 1
Which becomes (225 - 222) + 1 = 4.
Putting it altogether it would look something like this:
Dim a As String
Dim total As Double
Dim splits() As String
a = Dgv.Item(8, Dgv.CurrentRow.Index).Value.ToString()
splits = a.Split(New Char() { "-" })
total = (CDbl(splits(1)) - CDbl(splits(0))) + 1
Dgv.Item(9, Dgv.CurrentRow.Index).Value = total
Split returns an array. something like this. VB.Net is not my primary language but this should help.
dim arr = a.Split(New Char (){"-"})
total = ctype(arr(0), double) - ctype(arr(1),double)
Try this:
Dim aux() As String = a.Split("-"c)
total = CDbl(aux(0)) - CDbl(aux(1)) + 1
Dim a As string
Dim x As String
Dim total As Double
a = Dgv.Item(8, Dgv.CurrentRow.Index).Value
Dim ary() As String
x = a
ary() = x.Split("-")
total = CInt(ary(1)) - CInt(ary(0))
Dgv.Item(9, Dgv.CurrentRow.Index).Value = total
I have a string in VB.net that may contain something like the following:
This is a 0x000020AC symbol
This is the UTF-32 encoding for the Euro Symbol according to this article http://www.fileformat.info/info/unicode/char/20ac/index.htm
I'd like to convert this into
This is a € symbol
I've tried using UnicodeEncoding() class in VB.net (Framework 2.0, as I'm modifying a legacy application)
When I use this class to encode, and then decode I still get back the original string.
I expected that the UnicodeEncoding would recognise the already encoded part and not encode it against. But it appears to not be the case.
I'm a little lost now as to how I can convert a mixed encoded string into a normal string.
Background: When saving an Excel spreadsheet as CSV, anything outside of the ascii range gets converted to ?. So my idea is that if I can get my client to search/replace a few characters, such as the Euro symbol, into an encoded string such as 0x000020AC. Then I was hoping to convert those encoded parts back into the real symbols before I insert to a SQL database.
I've tried a function such as
Public Function Decode(ByVal s As String) As String
Dim uni As New UnicodeEncoding()
Dim encodedBytes As Byte() = uni.GetBytes(s)
Dim output As String = ""
output = uni.GetString(encodedBytes)
Return output
End Function
Which was based on the examples on the MSDN at http://msdn.microsoft.com/en-us/library/system.text.unicodeencoding.aspx
It could be that I have a complete mis-understanding of how this works in VB.net. In C# I can simply use escaped characters such as "\u20AC". But no such thing exists in VB.net.
Based on advice from Heinzi I implemented a Regex.Replace method using the following code, this appear to work for my examples.
Public Function Decode(ByVal s As String) As String
Dim output As String = ""
Dim sRegex As String = "0x[0-9a-zA-Z]{8}"
Dim r As Regex = New Regex(sRegex)
Dim myEvaluator As MatchEvaluator = New MatchEvaluator(AddressOf HexToString)
output = r.Replace(s, myEvaluator)
Return output
End Function
Public Function HexToString(ByVal hexString As Match) As String
Dim uni As New UnicodeEncoding(True, True)
Dim input As String = hexString.ToString
input = input.Substring(2)
input = input.TrimStart("0"c)
Dim output As String
Dim length As Integer = input.Length
Dim upperBound As Integer = length \ 2
If length Mod 2 = 0 Then
upperBound -= 1
Else
input = "0" & input
End If
Dim bytes(upperBound) As Byte
For i As Integer = 0 To upperBound
bytes(i) = Convert.ToByte(input.Substring(i * 2, 2), 16)
Next
output = uni.GetString(bytes)
Return output
End Function
Have you tried:
Public Function Decode(Byval Coded as string) as string
Return StrConv(Coded, vbUnicode)
End Function
Also, your function is invalid. It takes s as an argument, does a load of stuff and then outputs the s that was put into it instead of the stuff that was processed within it.
I am trying to run an event which will search through the different files in a given directory. The goal is to have it search for all files that begin with 'SP_', which are .sql files containing Stored Procedures. I would then like to add the full text of these Procedures to an array to be used later. This is causing an error when run, which I believe is because 'FullProcedureArray()', the string array I am trying to load does not have defined boundaries. When I declare it as 'FullProcedureArray(7)', or with some other value, it appears to run fine. But I don't want to have to hard-code a boundary for 'FullProcedureArray'; I would rather let it be defined by whatever the number of files in the folder is.
My question: Is there a way to declare 'FullProcedureArray' without having to give it an absolute value? I may just be missing something painfully obvious, but I haven't worked with this type of array much in the past. Thanks in advance for your help.
Dim AppDataLocation As String = "C:\Files\TestFiles\"
Dim ProcedureArray As String()
Dim ProcedureText As String
Dim FullProcedureArray() As String
Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(AppDataLocation)
Dim fileSystemInfo As System.IO.FileSystemInfo
Dim i As Integer = 0
For Each fileSystemInfo In sourceDirectoryInfo.GetFileSystemInfos
If (fileSystemInfo.Name.Contains("SP_")) Then
ProcedureArray = System.IO.File.ReadAllLines(AppDataLocation & fileSystemInfo.Name)
ProcedureText = Join(ProcedureArray, "")
FullProcedureArray.SetValue(ProcedureText, i)
i = (i + 1)
End If
Next
An array by definition has a fixed upper bound. If you don't want a fixed upper bound, don't use an array. Use, for example, a List(Of String) instead:
Dim AppDataLocation As String = "C:\Files\TestFiles\"
Dim ProcedureList As New List(Of String)
Dim sourceDirectoryInfo As New System.IO.DirectoryInfo(AppDataLocation)
For Each fileSystemInfo As System.IO.FileSystemInfo In sourceDirectoryInfo.GetFileSystemInfos
If (fileSystemInfo.Name.Contains("SP_")) Then
Dim ProcedureText As String = _
System.IO.File.ReadAllText(AppDataLocation & fileSystemInfo.Name)
ProcedureList.Add(ProcedureText)
End If
Next
If, for some reason, you still need the result as an array afterwards, simply convert the list to an array:
Dim myArray() As String = ProcedureList.ToArray()
If you don't want to give a size to your array or want to change at runtime, you can use "Redim Preserve"
http://msdn.microsoft.com/en-us/library/w8k3cys2%28v=vs.71%29.aspx