DataGridView检查所有行vb.net

Question

Private Sub comboBoxStudentID_SelectedIndexChanged(sender As Object, e As EventArgs) Handles comboBoxStudentID.SelectedIndexChanged
    For Each dr As DataGridViewRow In Me.dataGridViewStudent.Rows

        If dr.Cells(0).Value.ToString.Contains(comboBoxStudentID.Text) Then dr.Visible = True Else dr.Visible = False


    Next
End Sub

I've created this method to check and display a row that contains the same Student ID as selected from the comboBoxStudentID the problem is it only checks the first row of the DataGridView. How can I make it check all of the rows if there is match of Student ID?

Answer 1

Without knowing how your data is organized, you could do this by binding the DataGridView and the ComboBox to the same data source. Since this is not specified and looking at the snippet of code (which appears to work) it appears to loop through the rows and if the currently selected combo box text is contained in the first column cell, then make that row visible. Otherwise make the row invisible.

The posted code appears to work however there is one scenario you may want to consider. If the combo box contains the values that are in column one of the DataGridView , THEN, when the user selects a value in the combo box, the DataGridView will display ONLY those values that match the current combo box selection. This appears to be what you are trying to do.

The problem is how do you re-display all the rows?

Once the combo box selection has changed to some value, the user can delete the selection but all the rows will not display unless you handle another event. Also this strategy is not very user intuitive. One possible solution (below) simply adds a top item of “Reset” to the top of the combo boxes items. Then when the user selects “Reset” all row will become visible. Hope this helps.

To reiterate: you should consider setting this up with a DataSource and possibly a BindingSource where this is done for you automatically. Just a thought.

Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
  If ComboBox1.SelectedIndex > 0 Then
    For Each dr As DataGridViewRow In DataGridView1.Rows
      If (Not dr.IsNewRow) Then
        If dr.Cells(0).Value.ToString.Contains(ComboBox1.Text) Then
          dr.Visible = True
        Else
          dr.Visible = False
        End If
      End If
    Next
  Else
    For Each row As DataGridViewRow In DataGridView1.Rows
      row.Visible = True
    Next
  End If
End Sub