My datagridview is bound to a data table. I want to filter the datagridview without affecting data table. I know one way is to use bindingsource, but binding source will use column names in its filter. But I want to enable users to enter any string in a textbox to filter. So I pass datagridview by reference to a function PassFilter which removes unwanted rows in datagridview. I can see that it does execute rows removal in datagridview. But the problem is that when datagridview is shown on the form, it is unchanged, the same as the data table. I do not understand why rows are not removed on datagridview
The code is as follows:
DataGridView1.DataSource = table
PassFilter(DataGridView1, m_FilterQuick.strFilter.ToLower())
Private Sub PassFilter(ByRef datagridview As DataGridView, ByVal strFilter As String)
Dim i As Integer = 0
Dim j As Integer = 0
Dim containStr As Boolean = False
While i < datagridview.Rows.Count
j = 0
containStr = False
'If all cells in a row does not contain strFilter, delete this row from datagridview
While j < datagridview.Rows(i).Cells.Count
Dim c As DataGridViewCell = datagridview.Rows(i).Cells(j)
If Not c.Value Is DBNull.Value Or Nothing Then
If c.Value.ToString().ToLower().Contains(strFilter) Then
containStr = True
Exit While
End If
End If
j = j + 1
End While
If Not containStr Then
datagridview.Rows.RemoveAt(i)
End If
i = i + 1
End While
End Sub
Best Answer
Your big problem is that you're removing items in the DataGridViewRowCollection as you're iterating through that collection. Even if you're not getting an 'index out of range' error doing this you're going to end up removing the wrong row(s) as the index value of later rows change when you remove earlier rows.
What you should do is instead of removing rows in your row loop, add the row's index to a
List(Of Integers)
.After you're done iterating through all the rows in your DataGridView,
Reverse()
your list and use the row index values in yourList
to remove rows via theRemoveAt()
method.Here's what I mean: