[2005] - For Loop In DataGridView

[nolim8ts]

Hi All,

This post actually involves 2 questions

Question 1:

I would like to loop through column 2 of the datagridview so that each value can be placed into a string. Any suggestions on the for loop?

Question 2

In the second datagridview, I will be extracting all values to a CSV File(That part is complete). In the CSV file, I want to put a space after the 3rd and 4th comma. I would also like to remove the last comma on each line.

[jmcilhinney]

1.

For Each row As DatagridViewRow In myDataGridView.Rows
    MessageBox.Show(CStr(row.Cells(1).FormattedValue))
Next row

2. If you have a comma on the end of each line then you're doing it wrongly in the first place.

For rowIndex As Integer = 0 To myDataGridView.Rows.Count - 1 Step 1
    For columnIndex As Integer = 0 To myDatagridView.Columns.Count - 1 Step 1
        If columnIndex > 0 Then
            'Write a comma if an only if this is NOT the first column.
 
            If columnIndex = 3 OrElse columnIndex = 4 Then
                'Write a space in the fourth and fifth columns.
            End If
        End If
 
        'Write the cell value.
    Next columnIndex
Next rowIndex

You could also write the comma after the value and test that the current column was not the last, rather than writing it before and testing it was not the first.

[ComITSolutions]

Ans1:
some of the properties of Datagridview that u can use, RowCount,ColumnCount
to Know the No of Rows and columns. U can access value in any cell by
Datagridview(Col,Row).Value

SomeVal=Datagridview(Col,Row).Value
Datagridview(Col,Row).Value=SomeVal


Ans2:
If u post some code. It would be easy to analyse and suggest u the solution.

[nolim8ts]

Code for exporting datagridview

Private Sub ExportGrid()

        Using sfd As New SaveFileDialog()

            sfd.Filter = "CSV File|*.csv*"

            If sfd.ShowDialog = Windows.Forms.DialogResult.OK Then

                Dim I As Integer = 0
                Dim J As Integer = 0
                Dim cellvalue$
                Dim rowLine As String = ""

                Try

                    Dim objWriter As New System.IO.StreamWriter(sfd.FileName & ".csv", True)
                    For J = 0 To (DataGridViewData.Rows.Count - 2)
                        For I = 0 To (DataGridViewData.Columns.Count - 1)
                            If Not TypeOf DataGridViewData.CurrentRow.Cells.Item(I).Value Is DBNull Then
                                cellvalue = DataGridViewData.Item(I, J).Value
                            Else
                                cellvalue = ""
                            End If
                            rowLine = rowLine + cellvalue + ","
                        Next
                        objWriter.WriteLine(rowLine)
                        rowLine = ""
                    Next
                    objWriter.Close()
                    MsgBox("Data written to CSV File...")
                Catch ex As Exception

                    MsgBox("An error occured while writing to the CSV file..." + ex.ToString())

                End Try
            End If
        End Using
End Sub

I'm now comparing the code I found on the net with jmcilhinney's code to see if I can find a solution

Thanks jmcilhinney for your answer to question 1... Worked like a charm

[ComITSolutions]

Question 2

In the second datagridview, I will be extracting all values to a CSV File(That part is complete). In the CSV file, I want to put a space after the 3rd and 4th comma. I would also like to remove the last comma on each line

       For J = 0 To (DataGridViewData.Rows.Count - 2)
                        For I = 0 To (DataGridViewData.Columns.Count - 1)
                            If Not TypeOf DataGridViewData.CurrentRow.Cells.Item(I).Value Is DBNull Then
                                cellvalue = DataGridViewData.Item(I, J).Value
                            Else
                                cellvalue = ""
                            End If
                            rowLine = rowLine & cellvalue & IIf(I< DataGridViewData.Columns.Count - 1,",","") '<---I would also like to remove the last comma on each line
                        if i = 2 or i= 3 Then ' Since colums starts from 0
                              RowLine=rowLine & "  " '<---I want to put a space after the 3rd and 4th comma.
                        End if
                        Next
                        objWriter.WriteLine(rowLine)
                        rowLine = ""
                    Next

[nolim8ts]

Thanks ComITSolutions for your solution. Worked perfectly

There is one problem that I have run into though. When I am reading my CSV file into the datagridview, there is always a blank row in the datagridview. When I read the values from column 2 into the second datagridview using the website datascraper for loop, the last row of the datagridview has random data in it as the for loop is sending an empty value to the website.

Code to read CSV File: (Found On CodeProject.com)

Dim textline as string = ""
Dim SplitLine() as string

If system.IO.File.Exists(fname) = true then

Dim obj As New IO.StreamReader(fname)
Do While obj.Peek() <> -1
textline = obj.readline()
SplitLine = Split(textline, ",")
Me.DataGridView1.Rows.Add(SplitLine)
Loop

Else
MsgBox("File Not Found...")
End IF

I'm also trying to implement a progress bar when the website datascraper is running. I'm following this article Using the BackgroundWorker Component but getting stuck at

worker.ReportProgress(i, i & " iterations complete")

[ComITSolutions]

Dim textline as string = ""
Dim SplitLine() as string

If system.IO.File.Exists(fname) = true then

Dim obj As New IO.StreamReader(fname)

Me.DataGridView1.AllowUserToAddRows = False '<--- Add this line to avoid junk in last row
Do While obj.Peek() <> -1
textline = obj.readline()
SplitLine = Split(textline, ",")
Me.DataGridView1.Rows.Add(SplitLine)
Loop

Else
MsgBox("File Not Found...")
End IF

[nolim8ts]

Thanks ComITSolutions for the solution . Now to sort out the problem with the background worker reporting its progress (The application locks up after scraping all the data )