Delete multiple rows in a DataGridView(table)

Question

I have a datable "myTable", which is bind with a DataGridView "dgv". The DataGridView "dgv" has a checkbox column. My goal is to delete rows checked in a button event. The datatable is updated of course. Now my code is only working for deleting one row not for multiple rows.

Thanks for help.

 private void btnDel_Click(object sender, EventArgs e)
    {
        try
        {
            if (dgv.RowCount>0)
            {
                foreach (DataGridViewRow row in dgv.Rows)
                {
                    DataGridViewCheckBoxCell check = row.Cells[0] as DataGridViewCheckBoxCell;
                    if (check.Value != null)
                    {
                        if ((bool)check.Value)
                        {
                            DataRowView currentDataRowView = (DataRowView)dgv.CurrentRow.DataBoundItem;
                            DataRow dataRow = currentDataRowView.Row;

                            int n = dgv.CurrentRow.Index;
                            int intID = Convert.ToInt32(dgv.Rows[n].Cells[0].Value);
                            myTable.Rows.Remove(dataRow);
                            dgv.DataSource = myTable;

                            Int32 intVal = Convert.ToInt32(row.Cells[1].Value);
                            if (intVal == intID)
                            {
                                check.Value = null;
                            }
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show(ex.Message);
        }
    }

Do you get exception? My guess is that foreach should produce exception when you remove first row as collection is changed. — Ivan Ičin, Jun 19 '12 at 18:58
try to put this out of foreach loop: myTable.Rows.Remove(dataRow); — Ivan Ičin, Jun 19 '12 at 19:15
I don't think so, it will only remove one row and possibly getting an exception since dataRow is defined within foreach loop. — , Jun 19 '12 at 19:26
Oh sorry, wrong copy and paste, I thought on this line: dgv.DataSource = myTable; — Ivan Ičin, Jun 19 '12 at 19:31
@Love: Here you delete the row but not bind the gridview again so that only as per my thinking only last selected check row effected. — Saroop Trivedi, Jun 19 '12 at 19:55
I tested a scenario. Suppose there are 4 rows checked, the last twos are removed. — , Jun 19 '12 at 20:02

score 1 · Accepted Answer · answered Jun 20 '12 at 12:39

I found the solution. The error was caused by

 DataRowView currentDataRowView = (DataRowView)dgv.CurrentRow.DataBoundItem;

currentDataRowView is not the checked row. The correct code is:

                List<DataRow> toDelete = new List<DataRow>(); 
                for (int i = 0; i < dgv.Rows.Count; i++)
                {
                    {
                        DataGridViewRow row = dgv.Rows[i];
                        DataGridViewCheckBoxCell check = row.Cells[0] as DataGridViewCheckBoxCell;
                        if (check.Value != null && (bool)check.Value)
                        {
                            DataRow dataRow = (row.DataBoundItem as DataRowView).Row;
                            toDelete.Add(dataRow);
                        }
                    }
                }
                toDelete.ForEach(row => row.Delete());

Thanks everybody's help.

Josh · Answer 2 · 2012-06-19T20:06:05.970

Have you tried iterating by index instead of by a foreach? I think the CurrentRow may not be updating per each iterationg:

try {
                if (dgv.RowCount > 0) {
                    for (int i = 0; i < dgv.Rows.Count;i++ ) {
                        DataGridViewRow row = dgv.Rows[i];
                        DataGridViewCheckBoxCell check = row.Cells[0] as DataGridViewCheckBoxCell;
                        if (check.Value != null) {
                            if ((bool)check.Value) {
                                dgv.Rows[i].Selected = true;
                                dgv.Rows[i].Cells[0].Selected = true;
                                DataRowView currentDataRowView = (DataRowView)dgv.CurrentRow.DataBoundItem;
                                DataRow dataRow = currentDataRowView.Row;

                                int n = dgv.CurrentRow.Index;
                                int intID = Convert.ToInt32(dgv.Rows[n].Cells[0].Value);
                                myTable.Rows.Remove(dataRow);
                                dgv.DataSource = myTable;

                                Int32 intVal = Convert.ToInt32(row.Cells[1].Value);
                                if (intVal == intID) {
                                    check.Value = null;
                                }
                            }
                        }
                    }
                }
            } catch (Exception ex) {
                MessageBox.Show(ex.Message);
            }

You selected the row, but did you remove it? I saw that you commented the remove line. — , Jun 19 '12 at 20:05

ScottieMc · Answer 3 · 2012-06-19T20:37:48.630

0

It looks like you're only grabbing the CurrentRow from your DataGridView instead of the current row in your foreach loop. Also you are modifying the collection you are iterating through. This might work:

private void btnDel_Click(object sender, EventArgs e)
{
    try
    {
        List<DataRow> toDelete = new List<DataRow>();
        foreach (DataGridViewRow row in dgv.Rows)
        {
            DataGridViewCheckBoxCell check = row.Cells[0] as DataGridViewCheckBoxCell;
            if (check.Value != null && (bool)check.Value)
              toDelete.Add(((DataRowView)row.DataBoundItem).Row);
        }

        toDelete.ForEach(row => row.Delete());
    }
    catch (Exception ex)
    {
        MessageBox.Show(ex.Message);
    }
}

edited Jun 19 '12 at 20:37

answered Jun 19 '12 at 20:04

ScottieMc

656
9
16

Then how to delete rows from the table and bind it with the grid again? Where is the good place? – Jun 19 '12 at 20:08
Your table is already bound to the gridview, no need to rebind. Just delete the DataRows from the DataTable. – ScottieMc Jun 19 '12 at 20:09
I mean you have a list toDelete, how to apply it to my table? – Jun 19 '12 at 20:18
The toDelete list holds all of the "checked" rows from your DataTable. Once you delete the checked DataRows from the list, they are then removed from your GridView since it is bound to the DataTable. It may not be the most elegent solution but I believe it works. – ScottieMc Jun 19 '12 at 20:21
But how to delete rows in toDelete. Did you mean foreach(DataRow dr in myTable.Rows) { if (toDelete.Contains(dr)) myTable.Rows.Remove(dr);} – Jun 19 '12 at 20:24
Kind of, by writing `toDelete.ForEach(row => row.Delete());` I mean `foreach(DataRow dr in toDelete) dr.Delete();` – ScottieMc Jun 19 '12 at 20:25
It only removed the last row. – Jun 19 '12 at 20:36
Grr, not enough rep or I'd chat with you. Are you getting any exceptions? – ScottieMc Jun 19 '12 at 20:40
No exception, I can not chat with you because you only have one reputation.System prohibts your chatting. – Jun 19 '12 at 20:43
=/ yea sorry, wish I could help – ScottieMc Jun 19 '12 at 20:53

score 0 · Answer 4 · answered May 22 '14 at 06:40

ASPXPAGE:
<strong>Asp.Net : Delete Multiple Records form datagridview in one time<br />
        </strong>

        <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
            BackColor="White" BorderColor="#CCCCCC" BorderStyle="None" BorderWidth="1px"
            CellPadding="4" EnableModelValidation="True" ForeColor="Black">
            <Columns>
                <asp:TemplateField>
                    <EditItemTemplate>
                        <asp:CheckBox ID="CheckBox1" runat="server" />
                    </EditItemTemplate>
                    <ItemTemplate>
                        <asp:CheckBox ID="CheckBox1" runat="server" />
                    </ItemTemplate>
                </asp:TemplateField>
                <asp:BoundField DataField="id" HeaderText="Sr No" />
                <asp:BoundField DataField="doc_name" HeaderText="Name" />
                <asp:BoundField DataField="doc_add" HeaderText="Address" />
                <asp:BoundField DataField="doc_mob" HeaderText="Mobile No" />
                <asp:BoundField DataField="doc_email" HeaderText="Email" />
            </Columns>
            <FooterStyle BackColor="#CCCC99" ForeColor="Black" />
            <HeaderStyle BackColor="#333333" Font-Bold="True" ForeColor="White" />
            <PagerStyle BackColor="White" ForeColor="Black" HorizontalAlign="Right" />
            <SelectedRowStyle BackColor="#CC3333" Font-Bold="True" ForeColor="White" />
        </asp:GridView>
        <br />
        <asp:Button ID="Button1" runat="server" Font-Size="12pt"
            onclick="Button1_Click1" Text="Delete" />
        <br />



Code Behind Page:
SqlConnection conn = new SqlConnection(@"server=server-pc; database=HMS; integrated security=true");
    protected void Page_Load(object sender, EventArgs e)
    {
        if (IsPostBack == false)
        {
            load_data();
        }
    }

   public void load_data()
    {
        SqlDataAdapter adp = new SqlDataAdapter("select * from doc_master", conn);
        DataSet ds = new DataSet();
        adp.Fill(ds);
        GridView1.DataSource = ds.Tables[0];
        GridView1.DataBind();
    }
   protected void Button1_Click1(object sender, EventArgs e)
   {
       CheckBox ch;
       for (int i = 0; i < GridView1.Rows.Count; i++)
       {
           ch = (CheckBox)GridView1.Rows[i].Cells[0].Controls[1];
           if (ch.Checked == true)
           {
      int id = Convert.ToInt32(GridView1.Rows[i].Cells[1].Text);
      SqlCommand cmd = new SqlCommand("delete from doc_master where ID=" + id + " ", conn);
      conn.Open();
      cmd.ExecuteNonQuery();
      conn.Close();
           }
       }

       load_data();
   }

For detailed code visit: http://www.gtuguide.com/2014/05/deleting-multiple-rows-in-gridview.html

Delete multiple rows in a DataGridView(table)

4 Answers4

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