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Adding Dynamic Rows in Gridview with dropdownlists in asp.net

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how to dynamically add rows containing DropDownLists in ASP.Net GridView control

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  1. <html xmlns="http://www.w3.org/1999/xhtml">
  2. <head runat="server">
  3.     <title>Untitled Page</title>
  4. </head>
  5. <body>
  6.     <form id="form1" runat="server">
  7.     <div>
  8.     <asp:gridview ID="Gridview1" runat="server" ShowFooter="true" AutoGenerateColumns="false">
  9.         <Columns>
  10.         <asp:BoundField DataField="RowNumber" HeaderText="Row Number" />
  11.         <asp:TemplateField HeaderText="Header 1">
  12.             <ItemTemplate>
  13.                 <asp:DropDownList ID="DropDownList1" runat="server" AppendDataBoundItems="true">
  14.                 <asp:ListItem Value="-1">Select</asp:ListItem>
  15.                 </asp:DropDownList>
  16.             </ItemTemplate>
  17.         </asp:TemplateField>
  18.         <asp:TemplateField HeaderText="Header 2">
  19.             <ItemTemplate>
  20.                 <asp:DropDownList ID="DropDownList2" runat="server" AppendDataBoundItems="true">
  21.                 <asp:ListItem Value="-1">Select</asp:ListItem>
  22.                 </asp:DropDownList>
  23.             </ItemTemplate>
  24.         </asp:TemplateField>
  25.         <asp:TemplateField HeaderText="Header 3">
  26.             <ItemTemplate>
  27.                 <asp:DropDownList ID="DropDownList3" runat="server" AppendDataBoundItems="true">
  28.                 <asp:ListItem Value="-1">Select</asp:ListItem>
  29.                 </asp:DropDownList>
  30.             </ItemTemplate>
  31.             <FooterStyle HorizontalAlign="Right" />
  32.             <FooterTemplate>
  33.              <asp:Button ID="ButtonAdd" runat="server" Text="Add New Row"
  34.                     onclick="ButtonAdd_Click" />
  35.             </FooterTemplate>
  36.         </asp:TemplateField>
  37.         </Columns>
  38.         </asp:gridview>
  39.     </div>
  40.     </form>
  41. </body>
  42. </html>
  43.  
  44.  
  45. private ArrayList GetDummyData()
  46.     {
  47.         ArrayList arr = new ArrayList();
  48.         arr.Add(new ListItem("Item1", "1"));
  49.         arr.Add(new ListItem("Item2", "2"));
  50.         arr.Add(new ListItem("Item3", "3"));
  51.         arr.Add(new ListItem("Item4", "4"));
  52.         arr.Add(new ListItem("Item5", "5"));
  53.         return arr;
  54.     }
  55.  
  56.     private void FillDropDownList(DropDownList ddl)
  57.     {
  58.         ArrayList arr = GetDummyData();
  59.         foreach (ListItem item in arr)
  60.         {
  61.             ddl.Items.Add(item);
  62.         }
  63.     }
  64.  
  65.     private void SetInitialRow()
  66.     {
  67.         DataTable dt = new DataTable();
  68.         DataRow dr = null;
  69.  
  70.         //Define the Columns
  71.         dt.Columns.Add(new DataColumn("RowNumber", typeof(string)));
  72.         dt.Columns.Add(new DataColumn("Column1", typeof(string)));
  73.         dt.Columns.Add(new DataColumn("Column2", typeof(string)));
  74.         dt.Columns.Add(new DataColumn("Column3", typeof(string)));
  75.  
  76.         //Add a Dummy Data on Initial Load
  77.         dr = dt.NewRow();
  78.         dr["RowNumber"] = 1;
  79.         dt.Rows.Add(dr);
  80.  
  81.         //Store the DataTable in ViewState
  82.         ViewState["CurrentTable"] = dt;
  83.         //Bind the DataTable to the Grid
  84.         Gridview1.DataSource = dt;
  85.         Gridview1.DataBind();
  86.  
  87.         //Extract and Fill the DropDownList with Data
  88.         DropDownList ddl1 = (DropDownList)Gridview1.Rows[0].Cells[1].FindControl("DropDownList1");
  89.         DropDownList ddl2 = (DropDownList)Gridview1.Rows[0].Cells[2].FindControl("DropDownList2");
  90.         DropDownList ddl3 = (DropDownList)Gridview1.Rows[0].Cells[3].FindControl("DropDownList3");
  91.         FillDropDownList(ddl1);
  92.         FillDropDownList(ddl2);
  93.         FillDropDownList(ddl3);
  94.  
  95.     }
  96.     private void AddNewRowToGrid()
  97.     {
  98.  
  99.         if (ViewState["CurrentTable"] != null)
  100.         {
  101.             DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
  102.             DataRow drCurrentRow = null;
  103.  
  104.             if (dtCurrentTable.Rows.Count > 0)
  105.             {
  106.                 drCurrentRow = dtCurrentTable.NewRow();
  107.                 drCurrentRow["RowNumber"] = dtCurrentTable.Rows.Count + 1;
  108.                 //add new row to DataTable
  109.                 dtCurrentTable.Rows.Add(drCurrentRow);
  110.                 //Store the current data to ViewState
  111.                 ViewState["CurrentTable"] = dtCurrentTable;
  112.  
  113.                 for (int i = 0 ; i < dtCurrentTable.Rows.Count - 1; i++)
  114.                 {
  115.                     //extract the DropDownList Selected Items
  116.                     DropDownList ddl1 = (DropDownList)Gridview1.Rows[i].Cells[1].FindControl("DropDownList1");
  117.                     DropDownList ddl2 = (DropDownList)Gridview1.Rows[i].Cells[2].FindControl("DropDownList2");
  118.                     DropDownList ddl3 = (DropDownList)Gridview1.Rows[i].Cells[3].FindControl("DropDownList3");
  119.  
  120.                     // Update the DataRow with the DDL Selected Items
  121.                     dtCurrentTable.Rows[i]["Column1"] = ddl1.SelectedItem.Text;
  122.                     dtCurrentTable.Rows[i]["Column2"] = ddl2.SelectedItem.Text;
  123.                     dtCurrentTable.Rows[i]["Column3"] = ddl3.SelectedItem.Text;
  124.  
  125.                 }
  126.  
  127.                 //Rebind the Grid with the current data
  128.                 Gridview1.DataSource = dtCurrentTable;
  129.                 Gridview1.DataBind();
  130.             }
  131.         }
  132.         else
  133.         {
  134.             Response.Write("ViewState is null");
  135.         }
  136.  
  137.         //Set Previous Data on Postbacks
  138.         SetPreviousData();
  139.     }
  140.  
  141.     private void SetPreviousData()
  142.     {
  143.         int rowIndex = 0;
  144.         if (ViewState["CurrentTable"] != null)
  145.         {
  146.             DataTable dt = (DataTable)ViewState["CurrentTable"];
  147.             if (dt.Rows.Count > 0)
  148.             {
  149.                 for (int i = 0; i < dt.Rows.Count; i++)
  150.                 {
  151.                     //Set the Previous Selected Items on Each DropDownList on Postbacks
  152.                     DropDownList ddl1 = (DropDownList)Gridview1.Rows[rowIndex].Cells[1].FindControl("DropDownList1");
  153.                     DropDownList ddl2 = (DropDownList)Gridview1.Rows[rowIndex].Cells[2].FindControl("DropDownList2");
  154.                     DropDownList ddl3 = (DropDownList)Gridview1.Rows[rowIndex].Cells[3].FindControl("DropDownList3");
  155.  
  156.                     //Fill the DropDownList with Data
  157.                     FillDropDownList(ddl1);
  158.                     FillDropDownList(ddl2);
  159.                     FillDropDownList(ddl3);
  160.  
  161.                     if (i < dt.Rows.Count - 1)
  162.                     {
  163.                         ddl1.ClearSelection();
  164.                         ddl1.Items.FindByText(dt.Rows[i]["Column1"].ToString()).Selected = true;
  165.  
  166.                         ddl2.ClearSelection();
  167.                         ddl2.Items.FindByText(dt.Rows[i]["Column2"].ToString()).Selected = true;
  168.  
  169.                         ddl3.ClearSelection();
  170.                         ddl3.Items.FindByText(dt.Rows[i]["Column3"].ToString()).Selected = true;
  171.                     }
  172.  
  173.                     rowIndex++;
  174.                 }
  175.             }
  176.         }
  177.     }
  178.  
  179.     protected void Page_Load(object sender, EventArgs e)
  180.     {
  181.         if (!Page.IsPostBack)
  182.         {
  183.             SetInitialRow();
  184.         }
  185.     }
  186.     protected void ButtonAdd_Click(object sender, EventArgs e)
  187.     {
  188.         AddNewRowToGrid();
  189.     }

URL: http://www.aspsnippets.com/Articles/Adding-Dynamic-Rows-in-GridView-with-DropDownLists-in-ASP.Net.aspx

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