Question

    private void btnSaveStudy_Click(object sender, EventArgs e)
        {
            string valueFromlbl = string.Empty;

            for(int i = 0; i < tableContent.Rows.Count; i++)
            {
                for(int j = 0; j < tableContent.Rows[i].Cells.Count; j++)
                {
                    foreach(Control ctrl in tableContent.Rows[i].Cells[j].Controls)
                    {
                        Label lbl = ctrl as Label;
                        if(lbl != null)
                        {
                            valueFromlbl = lbl.Text;
                        }
                    }
                }
            }
        }

protected void Page_Load(object sender, EventArgs e)
{
HtmlTable table = null;
                HtmlTableRow row = null;
                HtmlTableCell cell = null;
                studyNumber = studyNumber + 1;
                uniqueID = uniqueID + 1;

                for(int i = 0; i < 5; i++)
                {
                    table = new HtmlTable();
                    row = new HtmlTableRow();

                    tableContent.Controls.AddAt(i, row);
                    for(int j = 0; j < 3; j++)
                    {
                        cell = new HtmlTableCell();
                        cell.Attributes.Add("Class", "csstablelisttd");
                        row.Attributes.Add("Class", "csstextheader");
                        row.Controls.AddAt(j, cell);

                        if(i == 0 && j == 0)
                        {
                            cell.InnerText = "Study : " + Convert.ToInt32(studyNumber);

                        }
                        else if(i == 1 && j == 0)
                        {
                            cell.InnerText = "Modality" + " : " + modality;
                        }
                        else if(i == 2 && j == 0)
                        {
                            cell.InnerText = "Start Date" + " : " + DateTime.Now.ToString("dd-MMM-yyyy");
                        }
                        else if(i == 3 && j == 0)
                        {
                            cell.InnerText = "Accession Number" + " : " + accessionNumber;
                        }
                        else if(i == 4 && j == 0)
                        {
                            Button btnSaveStudy = new Button();
                            btnSaveStudy.ID = "btnSaveStudy" + uniqueID;
                            btnSaveStudy.Text = "Save";
                            btnSaveStudy.Attributes.Add("Class", "cssbutton");
                            cell.Controls.Add(btnSaveStudy);
                            btnSaveStudy.Click += new EventHandler(btnSaveStudy_Click);
                        }
                        if(i == 1 && j == 1)
                        {
                            cell.InnerText = "AE Title" + " : " + schedule_Station_AE_Title;
                        }
                        else if(i == 1 && j == 2)
                        {
                            cell.InnerText = "Station Name" + " : " + schedule_Station_Name;
                        }
                        else if(i == 2 && j == 1)
                        {
                            cell.InnerText = "Start time" + " : " + startTime;
                        }
                        else if(i == 3 && j == 1)
                        {
                            cell.InnerText = "End time" + " : " + endTime;
                        }

                        else if(i == 2 && j == 2)
                        {
                            Label lblPriority = new Label();
                            lblPriority.ID = "lblPriority" + uniqueID;
                            lblPriority.Text = "Priority : ";
                            DropDownList ddlPriority = new DropDownList();
                            ddlPriority.ID = "ddlPriority" + uniqueID;
                            ddlPriority.Attributes.Add("Class", "csstextbox");
                            ddlPriority.Items.Add(new ListItem("MEDIUM", "4"));
                            ddlPriority.Items.Add(new ListItem("STAT", "1"));
                            ddlPriority.Items.Add(new ListItem("HIGH", "2"));
                            ddlPriority.Items.Add(new ListItem("ROUTINE", "3"));
                            ddlPriority.Items.Add(new ListItem("LOW", "5"));
                            cell.Controls.Add(lblPriority);
                            cell.Controls.Add(ddlPriority);
                        }
                        else if(i == 3 && j == 2)
                        {
                            Label lblStudy = new Label();
                            lblStudy.ID = "lblStudy" + uniqueID;
                            lblStudy.Text = "Study : ";
                            DropDownList ddlStudyList = new DropDownList();
                            ddlStudyList = BindStudy(ddlStudyList, Convert.ToInt32(acqModalityID), uniqueID);
                            ddlStudyList.Attributes.Add("Class", "csstextbox");
                            cell.Controls.Add(lblStudy);
                            cell.Controls.Add(ddlStudyList);
                        }
                    }
                }
            }}
I have added controls to table cell but not find any control

Answer 1

This appears to be an issue with the execution order. Remember that your controls are not added until after your click event. So when your button click fires, the controls need to have been re-added before you can check for their existence.

(I would post this as a comment, but evidently, as I am new, I don’t have enough points)