How to add TemplateField to a gridview in the code behind?

Question

I have a DropDownList which has a list of tables. Under it there is GridView. Based on the table selected from the drop down list box, I will populate the GridView

Answer 1

I have done the same functionality as below with custom paging(using storedProc) for 100+ million records in many tables, update, delete and insert also:

CREATE PROCEDURE [dbo].[sp_Mk]
    @PageIndex  INT,
    @PageSize INT,
    @tableName nvarchar(255),
    @totalRow INT Output
AS
BEGIN 
DECLARE @sql NVARCHAR(MAX)
Declare @anotherSql NVARCHAR(1000)
DECLARE @ParamDefinition NVARCHAR(500)

--DECLARE @totalRow INT
Set @sql = 'WITH TempResult AS( SELECT *  FROM '+@tableName+'), TempCount AS ( SELECT COUNT(*) AS MaxRows FROM TempResult )
SELECT * FROM TempResult, TempCount ORDER BY (Select Null)
    OFFSET '+CONVERT(VARCHAR(20),(@PageIndex-1)*@PageSize) +' ROWS FETCH NEXT '+CONVERT(VARCHAR(20),@PageSize)+' ROWS ONLY'

PRINT @SQL
EXECUTE sp_executesql @SQL
Set @anotherSql=N'SELECT COUNT(*) as totalRow FROM '+@tableName
SET @ParamDefinition = N'@totalRowOutPut INT  OUTPUT'
--PRINT @anotherSql
Execute sp_executesql @anotherSql, 
@ParamDefinition, 
--@tableNameInput=@tableName, 
@totalRowOutPut=@totalRow OUTPUT
End





            

            

            
                
                    
                
            





SqlConnectionStringBuilder builder;
        int pageSize = 100;
        protected void Page_Load(object sender, EventArgs e)
        {
            builder = new SqlConnectionStringBuilder(connectionString);
            if (!IsPostBack)
            {
                using (SqlConnection connObj = new SqlConnection(connectionString))
                {
                    connObj.Open();

                    using (SqlDataAdapter adapter = new SqlDataAdapter("SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG='" + builder.InitialCatalog + "' AND TABLE_NAME Not In('AspNetUsers') Order By TABLE_NAME", connObj))
                    {
                        DataSet ds = new DataSet();
                        adapter.Fill(ds);
                        ddlTableNames.DataSource = ds;
                        ddlTableNames.DataBind();
                        ddlTableNames.Items.Insert(0, new ListItem("Select Table", String.Empty));
                    }
                }
            }
            //}
            //else if(ddlTableNames.Visible) ddlTableNames.Visible = false;
        }

        protected void ddlTableNames_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (ddlTableNames.SelectedValue != "")
            {
                grdDynamic.Visible = true;
                this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value));
            }
            else if (grdDynamic.Visible == true) grdDynamic.Visible = false;
        }

        private void BindGrid(string selectedTable, int pageIndex, bool addNewRow=false)
        {
            using (SqlConnection connObj = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand("sp_Mk", connObj))
                {
                    int recordCount=0;
                    cmd.CommandType = CommandType.StoredProcedure;
                    cmd.Parameters.AddWithValue("@PageIndex", pageIndex);
                    cmd.Parameters.AddWithValue("@PageSize", pageSize);
                    cmd.Parameters.AddWithValue("@tableName", ddlTableNames.SelectedValue);
                    SqlParameter totalRow = new SqlParameter("@totalRow", SqlDbType.Int, 4);
                    totalRow.Direction = ParameterDirection.Output;
                    cmd.Parameters.Add(totalRow);
                    connObj.Open();
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    DataSet ds = new DataSet();
                    adapter.Fill(ds);
                    grdDynamic.DataSource = ds.Tables[0];
                    if (addNewRow) ds.Tables[0].Rows.Add();
                    recordCount = Convert.ToInt32(ds.Tables[1].Rows[0].ItemArray[0]);
                    grdDynamic.DataBind();

                    connObj.Close();
                    if (totalRow.Value != DBNull.Value)
                    {

                    }
                    this.PopulatePager(recordCount, pageIndex);
                }
            }
        }

        private void PopulatePager(int recordCount, int currentPage)
        {
            double dblPageCount = (double)((decimal)recordCount / pageSize);
            int pageCount = (int)Math.Ceiling(dblPageCount);
            List pages = new List();
            if (pageCount > 0)
            {
                pages.Add(new ListItem("First", "1", currentPage > 1));
                for (int i = 1; i <= pageCount; i++)
                {
                    ListItem item=new ListItem(i.ToString(), i.ToString(), i != currentPage);
                    if (i == currentPage) item.Attributes.Add("style", "color:red;");
                    pages.Add(item);
                }
                pages.Add(new ListItem("Last", pageCount.ToString(), currentPage < pageCount));
            }
            rptPager.DataSource = pages;
            rptPager.DataBind();
        }

        protected void Page_Changed(object sender, EventArgs e)
        {
            int pageIndex = int.Parse((sender as LinkButton).CommandArgument);
            hdnPageIndex.Value = pageIndex.ToString();
            this.BindGrid(ddlTableNames.SelectedValue, pageIndex);
        }

        protected void OnRowEditing_grdDynamic(object sender, GridViewEditEventArgs e)
        {
            grdDynamic.EditIndex = e.NewEditIndex;
            this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value));
        }

        protected void OnRowUpdating_grdDynamic(object sender, GridViewUpdateEventArgs e)
        {
            GridViewRow row = grdDynamic.Rows[e.RowIndex];
            string updateStatement = string.Empty;
            for (int x = 0; x < row.Cells.Count; x++) updateStatement = updateStatement + grdDynamic.DataKeys[e.RowIndex].Values[x] + " = " + grdDynamic.DataKeys[e.RowIndex].Values[x] + ", ";
            //int recordId = Convert.ToInt32(grdDynamic.DataKeys[e.RowIndex].Values[0]);
            using (SqlConnection con = new SqlConnection(connectionString))
            {
                //using (SqlCommand cmd = new SqlCommand("UPDATE "+selectedTable"+ SET Name = @Name, Country = @Country WHERE CustomerId = @CustomerId"))
                {
                    cmd.Connection = con;
                    con.Open();
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
            }
            grdDynamic.EditIndex = -1;
            this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value));
        }

        protected void OnRowCancelingEdit_grdDynamic(object sender, EventArgs e)
        {
            grdDynamic.EditIndex = -1;
            this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value));
        }

        protected void OnRowDeleting_grdDynamic(object sender, GridViewDeleteEventArgs e)
        {
            int recordId = Convert.ToInt32(grdDynamic.DataKeys[e.RowIndex].Values[0]);
            using (SqlConnection con = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand("DELETE FROM " + ddlTableNames.SelectedValue + " WHERE RecordId = @recordId"))
                {
                    cmd.Connection = con;
                    con.Open();
                    cmd.ExecuteNonQuery();
                    con.Close();
                }
            }
            this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value));
        }

        protected void btnGo_Click(object sender, EventArgs e)
        {   int myInt;
            if(txtPageSize.Text!=null && txtPageSize.Text !=string.Empty)
                if(int.TryParse(txtPageSize.Text, out myInt)) pageSize = myInt;
            hdnPageIndex.Value = "1";
            this.BindGrid(ddlTableNames.SelectedValue, 1);
        }

        protected void AddNewButton_Click(object sender, EventArgs e)
        {
            hdnPageIndex.Value="1";
            this.BindGrid(ddlTableNames.SelectedValue, Convert.ToInt32(hdnPageIndex.Value), true);
        }

        protected void OnRowDataBound_grdDynamic(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow && e.Row.RowIndex != grdDynamic.EditIndex)
            {
                (e.Row.Cells[0].Controls[2] as LinkButton).Attributes["onclick"] = "return confirm('Do you want to delete this row?');";
            }
        }

Hope it helps: