How to access dynamically created control's value on button click event

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I have created on web page using asp.net.After selecting particular student(name),from that student's id ,I am fetching all subject offered to that student from database.User can append/write marks got/achieved to that student(Taking input from user).After clicking on button,want to save data. Here I have created dynamical control but I unable to access it on button click event.How to do that?

What I have tried:

Code ASPX:

<asp:Panel ID="PnlStudent" runat="server" Visible="false">
                    <asp:Table ID="tblStudent" runat="server" Width="600px">
                        <asp:TableRow>
                            <asp:TableCell Height=" 32px" ForeColor="#32417a" BackColor="#e5e5e5" Width="156px">
                                Subject
                            </asp:TableCell>
                            <asp:TableCell Height=" 32px" ForeColor="#32417a" BackColor="#e5e5e5" Width="156px">
                                Marks Optined
                            </asp:TableCell>
                        </asp:TableRow>
                    </asp:Table>
                </asp:Panel>

Code in Cs file :

protected void ddlStudent_SelectedIndexChanged(object sender, EventArgs e)
    {
           // fetch from Student table


      if (dsStudent != null)
                {
                    DataTable dt = dsStudent.Tables["Student"];
                    if (dt.Rows.Count > 0)
                    {
                        PnlStudent.Visible = true;
                        foreach (DataRow dr in dt.Rows)
                        {
                            TableRow NewRow1 = new TableRow();

                            TableCell NewCell1 = new TableCell();
                            NewCell1.Width = Unit.Pixel(156);
                            NewCell1.Height = Unit.Pixel(32);
                            NewCell1.ForeColor = System.Drawing.Color.LightSlateGray;
                            NewCell1.BackColor = System.Drawing.Color.LightGray;

                            Label newLable1 = new Label();
                            newLable1.Text = dr["Subject"].ToString();


                            NewCell1.Controls.Add(newLable1);
                            NewRow1.Cells.Add(NewCell1);

                            TableCell NewCell2 = new TableCell();
                            NewCell2.Height = Unit.Pixel(32);
                            NewCell2.BackColor = System.Drawing.Color.LightGray;

                            TextBox txtBox1 = new TextBox();

                            NewCell2.Controls.Add(txtBox1);
                            NewRow1.Cells.Add(NewCell2);
                            tblStudent.Rows.Add(NewRow1);
                        }


                    }
                }
}


protected void BtnSave_Click(object sender, EventArgs e)
    {
}

Posted 27-Aug-17 21:08pm

Member 11589429

Updated 28-Aug-17 2:38am

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Sheila Pontes · Answer 1 · 2017-08-28T02:38:00

Hi,

To do what you wish, first type a unique identification for each component that you add dynamically, like this:

C#

PnlStudent.Visible = true;
int index_row = 0;
foreach (DataRow dr in dt.Rows)
{
    TableRow NewRow1 = new TableRow();

    TableCell NewCell1 = new TableCell();
    NewCell1.Width = Unit.Pixel(156);
    NewCell1.Height = Unit.Pixel(32);
    NewCell1.ForeColor = System.Drawing.Color.LightSlateGray;
    NewCell1.BackColor = System.Drawing.Color.LightGray;

    Label newLable1 = new Label();
                    
    //type id in the label component
    newLable1.ID = "mylabel_" + index_row.ToString();
    
    newLable1.Text = dr["Subject"].ToString();
    NewCell1.Controls.Add(newLable1);
    NewRow1.Cells.Add(NewCell1);

    TableCell NewCell2 = new TableCell();
    NewCell2.Height = Unit.Pixel(32);
    NewCell2.BackColor = System.Drawing.Color.LightGray;

    TextBox txtBox1 = new TextBox();
    
    //type id in the textbox component 
    txtBox1.ID = "mytext_" + index_row.ToString();

    NewCell2.Controls.Add(txtBox1);
    NewRow1.Cells.Add(NewCell2);
    tblStudent.Rows.Add(NewRow1);

    index_row++;
}

To read the data in the component, do this:

C#

protected void BtnSave_Click(object sender, EventArgs e)
{
    string valuemytextbox, valuemylabel;
    int index_row = 0;
    bool header = true; // the first line is header 
    
    //read each line
    foreach (TableRow row in tblStudent.Rows)
    {
        // the first line is header
        if (header)
        {
            header = false;
        }
        else
        {
            //find components in the row
            valuemytextbox = ((TextBox)row.FindControl("mytext_" + index_row.ToString())).Text;
            valuemylabel = ((Label)row.FindControl("mylabel_" + index_row.ToString())).Text;

            //salve data in database
            ....

            index_row++;
        }
    }
}