在GridView中删除不起作用

Question

i designed a page for admin to search users from database table using a Get button and delete users in gridview

This my source coding..

                <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" AutoGenerateDeleteButton="True" DataKeyNames="username"  EnableModelValidation="True" OnRowDeleting="GridView1_RowDeleting" OnSelectedIndexChanged="GridView1_SelectedIndexChanged1">
                    <Columns>
                        <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" ReadOnly="True" SortExpression="Id" />
                        <asp:BoundField DataField="name" HeaderText="name" SortExpression="name" />
                        <asp:BoundField DataField="adm" HeaderText="adm" SortExpression="adm" />
                        <asp:BoundField DataField="mobno" HeaderText="mobno" SortExpression="mobno" />
                        <asp:BoundField DataField="branch" HeaderText="branch" SortExpression="branch" />
                        <asp:BoundField DataField="year" HeaderText="year" SortExpression="year" />
                        <asp:BoundField DataField="username" HeaderText="username" ReadOnly="True" SortExpression="username" />
                        <asp:BoundField DataField="password" HeaderText="password" SortExpression="password" />
                        <asp:BoundField DataField="usertype" HeaderText="usertype" SortExpression="usertype" />
                    </Columns>
                </asp:GridView>
                <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:CanteenConnectionString %>" SelectCommand="SELECT * FROM [Hosteller]" DeleteCommand="DELETE FROM Hosteller WHERE (username = @username)">
                    <DeleteParameters>
                        <asp:Parameter Name="username" />
                    </DeleteParameters>
                </asp:SqlDataSource>
            </td>
        </tr>
        <tr>
            <td>&nbsp;</td>
        </tr>
        <tr>
            <td>&nbsp;</td>
        </tr>
    </table>

</form>

 protected void btnget_Click(object sender, EventArgs e)
        {
            DataTable dt = new DataTable();
            string ConString = "Data Source=sheikha-pc\\sqlexpress;Initial Catalog=Canteen;Integrated Security=True";
            SqlConnection con = new SqlConnection(ConString);
            string qry = "select id,name,adm,mobno,branch,year,username,password,usertype from Hosteller where adm='" + txtsearch1.Text + "'";
            SqlDataAdapter adpt = new SqlDataAdapter(qry, con);
            adpt.Fill(dt);
            if (dt.Rows.Count == 0)
            {
                GridView1.EmptyDataText = "No data found";
                GridView1.DataBind();
            }
            else
            {
                GridView1.DataSource = dt;
                GridView1.DataBind();
            }

        }

this is the coding that i wrote for GET button

the problem is when i click on delete it doesnt work! please help.........

Answer 1

It looks like the issue here is that you are overriding the data source in your code behind. If you comment out the code in "btnget_Click" and add the datasource to GridView1 it should work to delete.

            <asp:GridView ID="GridView1" DataSourceID="SqlDataSource1" runat="server" AutoGenerateColumns="False" AutoGenerateDeleteButton="True" DataKeyNames="username"  EnableModelValidation="True" OnRowDeleting="GridView1_RowDeleting" OnSelectedIndexChanged="GridView1_SelectedIndexChanged1">
                <Columns>
                    <asp:BoundField DataField="Id" HeaderText="Id" InsertVisible="False" ReadOnly="True" SortExpression="Id" />
                    <asp:BoundField DataField="name" HeaderText="name" SortExpression="name" />
                    <asp:BoundField DataField="adm" HeaderText="adm" SortExpression="adm" />
                    <asp:BoundField DataField="mobno" HeaderText="mobno" SortExpression="mobno" />
                    <asp:BoundField DataField="branch" HeaderText="branch" SortExpression="branch" />
                    <asp:BoundField DataField="year" HeaderText="year" SortExpression="year" />
                    <asp:BoundField DataField="username" HeaderText="username" ReadOnly="True" SortExpression="username" />
                    <asp:BoundField DataField="password" HeaderText="password" SortExpression="password" />
                    <asp:BoundField DataField="usertype" HeaderText="usertype" SortExpression="usertype" />
                </Columns>
            </asp:GridView>

And the code behind:

protected void btnget_Click(object sender, EventArgs e)
        {


        }

This might not be what you want though. This will load the data on page load so the user will not need to click the button in order to get the results.

If you want the user to click the button then you will need to rewirte your code a bit and put some code in RowDeleting() as @Cal279 sugested in his comment.