How to remove row of data gridview in vb.net? - html

Question

I want to remove the rows of data gridview after use a query sql from database
i use this code
Try
Thread.CurrentThread.CurrentCulture = CultureInfo.GetCultureInfo("en-US")
Dim strConn As String
strConn = "DRIVER=PostgreSQL ANSI;SERVER=127.0.0.1;PORT=5432;UID=postgres;Password=azerty79;DATABASE=" & ComboBox2.Text & ";pwd=postgres;ReadOnly=0"
'strConn = "DRIVER={PostgreSQL ANSI};UID=postgres;pwd=postgres;LowerCaseIdentifier=0;UseServerSidePrepare=0;ByteaAsLongVarBinary=0;"
'strConn = "dsn=test;uid=postgres;pwd=postgres"
Dim cnDb As OdbcConnection
Dim dsDB As New DataSet
Dim adDb As OdbcDataAdapter
Dim cbDb As OdbcCommandBuilder
Dim cmd As OdbcCommand
Dim cmd1 As OdbcCommand
Dim adDb1 As OdbcDataAdapter
Dim dsDB1 As New DataSet
Dim dt As New DataTable
Dim pic As New PictureBox
cnDb = New OdbcConnection(strConn)
cnDb.Open()
dsDB = New DataSet
adDb = New OdbcDataAdapter
cbDb = New OdbcCommandBuilder(adDb)
'cmd.Parameters.Add("#id", OdbcType.NVarChar, "1")
For i = 1 To 3
' Create the SelectCommand.
cmd = New OdbcCommand("select b.id_detail_polygon,b.mappe_3,b.type_d_affaire,b.consistance,b.nbr_borne ,num_bornes,a.x,a.y,b.superficie_cs from point a right join (select (dp).path[1] d1,(dp).path[2] d2,(dp).geom d3 from (select st_dumppoints(geom) dp from polygon where id_detail_polygon ='" & i & "')a)dptable on st_equals(a.geom,dptable.d3),polygon b where id_detail_polygon='" & i & "'", cnDb) ' & _
'"WHERE id = ? ", cnDb)
cmd1 = New OdbcCommand("SELECT num_bornes,x,y FROM point RIGHT JOIN (SELECT (dp).path[1] As ringID,(dp).path[2] As pointID,(dp).geom ptgeom FROM (SELECT st_dumppoints(geom) dp FROM polygon WHERE id_detail_polygon='" & i & "' ) a) dptable ON ST_Equals(point.geom, dptable.ptgeom) ORDER BY dptable.pointID;", cnDb)
'cmd.Parameters.Add("#id", OdbcType.NVarChar, "1")
adDb = New OdbcDataAdapter(cmd)
adDb1 = New OdbcDataAdapter(cmd1)
adDb.Fill(dsDB, ComboBox1.Text)
adDb1.Fill(dsDB1, ComboBox1.Text)
DataGridView2.DataSource = dsDB
DataGridView3.DataSource = dsDB1
DataGridView2.DataMember = ComboBox1.Text
DataGridView3.DataMember = ComboBox1.Text
DataGridView2.DataSource = dsDB.DefaultViewManager
DataGridView3.DataSource = dsDB1.DefaultViewManager
Dim StrExport As String = ""
For Each R As DataGridViewRow In DataGridView3.Rows
For Each C As DataGridViewCell In R.Cells
If Not C.Value Is Nothing Then
StrExport &= C.Value.ToString & " "
Else
End If
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine
Next
Dim fName As String = ""
SaveFileDialog1.InitialDirectory = "C:\Users\pc\Desktop\"
SaveFileDialog1.Filter = "dat files (*.dat)|*.dat"
SaveFileDialog1.FilterIndex = 2
SaveFileDialog1.Title = "dat"
SaveFileDialog1.RestoreDirectory = True
If (SaveFileDialog1.ShowDialog() = System.Windows.Forms.DialogResult.OK) Then
fName = SaveFileDialog1.FileName
End If
For j = 0 To 0
For x = 0 To DataGridView2.RowCount - 1
Dim tw As IO.TextWriter = New IO.StreamWriter(fName)
tw.Write(DataGridView2.Rows(j).Cells(0).Value & vbCr & vbLf & DataGridView2.Rows(j).Cells(1).Value & vbCr & vbLf & DataGridView2.Rows(j).Cells(2).Value & vbCr & vbLf & DataGridView2.Rows(j).Cells(3).Value & vbCr & vbLf & DataGridView2.Rows(j).Cells(4).Value & vbCr & vbLf & StrExport & " " & DataGridView2.Rows(j).Cells(8).Value)
tw.Close()
Next
Next
For Each row As DataGridViewRow In DataGridView2.Rows
DataGridView2.Rows.Remove(row)
Next
Next
Catch ex As Exception
MsgBox("ERROR :" + ex.Message)
End Try
MsgBox("Exported", vbInformation, "Successful")
But i get this problem below

Answer 1

Edit
Basing on your comment, I understand you don't want the data gone from the database bug instead from the grid. I would advise against using a dataset as you have done. A DataSet has a collection of DataTable objects that you can manipulate. I also see that you are removing every row in a For Each loop. You can remove these rows from the table or call the clear method on that table and you grid should reflect it. I have left the original answer to explain why this was happening. Edit
Without being able to tell what the error is, I'll just tell you that you cannot programmatically remove a row from a DataGridView if the DataSource is not an IBindingList with change event notification. OdbcDataAdapter does not implement IBindingList anywhere in its inheritance chain.
If you are not willing to change what you bind to, you can re-run the query to get the items and bind the grid again.