Im sure someone out there can help, im totally new to coding but getting into it and really enjoying. I know this is such a simple question out there for you folks but i have the following, I load a spread sheet of strings (2 columns) into a datagridview the reason i do this because there is over 100,000 find and replaces and these will generally sit within and existing string when searching, then from there i want to simply search a txt file and find and replace a number of strings in it. So it would check each row in a datagrid take from column 1 the find and use column 2 to replace then outputs the string to another txt file once the find and replace has taken place. My current results are that it just takes what was in the first file and copies without replacing in the second find.
Any assistance is gratefully received, many thanks.
Please see below my amateur code:-
Private Sub CmdBtnTestReplace_Click(sender As System.Object, e As System.EventArgs) Handles CmdBtnTestReplace.Click
Dim fName As String = "c:\backup\logs\masterUser.txt"
Dim wrtFile As String = "c:\backup\logs\masterUserFormatted.txt"
Dim strRead As New System.IO.StreamReader(fName)
Dim strWrite As New System.IO.StreamWriter(wrtFile)
Dim s As String
Dim o As String
For Each row As DataGridViewRow In DataGridView1.Rows
If Not row.IsNewRow Then
Dim Find1 As String = row.Cells(0).Value.ToString
Dim Replace1 As String = row.Cells(1).Value.ToString
Cursor.Current = Cursors.WaitCursor
s = strRead.ReadToEnd()
o = s.Replace(Find1, Replace1)
strWrite.Write(o)
End If
Next
strRead.Close()
strWrite.Close()
Cursor.Current = Cursors.Default
MessageBox.Show("Finished Replacing")
End Sub
1. What you are doing is :
fName and put it in ss and put the result in oo to the existing content of the file wrtFileBut that doesn't work because, on the secund iteration of the loop, strRead is already at the end of your loaded file, then there is nothing to read anymore, and s is always an empty string starting from the secund iteration.
Furthermore, because s is empty, o will be empty aswell.
And last of all, even if you manage to re-read the content of the file and replace the words, strWrite will not clear the initial content of the output file, but will write the resulting replaced string (o) after the previously updated content of the file.
2. Since you loaded the content of the file in a string (s = strRead.ReadToEnd()), why don't you :
s string before the For-Next blocks = s.Replace(Find1, Replace1)3. However, improving your understanding of how streams work, what should be considered and what are forbidden is a bit outside the scope of SO I think; such documentation could be found/gathered on the MSDN page or with the help of your friend : google. The same applies for finding out/thinking of how you should arrange your code, how to achieve your goal.
Let's take an example :
' Content of your file :
One Two Three Four Five Six
' Content of your DataGridView :
One | Two
Two | Three
Three | Four
Four | Five
Five | Six
Six | Seven
The resulting replacement text at the end of a similar routine as yours will be :
Seven Seven Seven Seven Seven Seven ' :/
' while the expected result would be :
Two Three Four Five Six Seven
And that's because of the iteration : already replaced portions of your file (or loaded file content) could get replaced again and again. To avoid that, either :
So, before using an interesting object in the framework :
So, like I said in 2., move those ReadAllText() and Write() outside the For/Next block to start from and have a look at the resulting output (Ask specific questions in comments when google can't answer) Then if you're OK with it even if issue like the One Two Three example above could occur, then voila ! Otherwise, use google to gather more examples on "splitting text in words" and reformating the whole, have some tries, then get back here if you're stuck on precise issues.
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