I have seen many forum posts regarding how
to save a DataTable in Viewstate and display those records in a GridView
without saving in the database. In consideration of those requirements I
decided to write an article on it. So let us start creating a web
application as:
Now switch to design mode, it will be like this.
- "Start" - "All Programs" - "Microsoft Visual Studio".
- "File" - "New WebSite" - "C#" - "Empty WebSite" (to avoid adding a master page).
- Provide the web site a name such as "SaveDataTableInViewsate" or another as you wish and specify the location.
- Then right-click on Solution Explorer - "Add New Item" - Add Web Form.
- Drag and drop one button and three textBoxes onto the <form> section of the Default.aspx page.
- Now the default.aspx page source code will look such as follows.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body style="background-color: #0000FF"> <form id="form1" runat="server"> <table style="color: White;margin-top:30px;margin-left:10px"> <tr> <td> Author Name </td> <td> Book Name </td> <td> Book Type </td> <td> Publisher </td> </tr> <tr> <td> <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> </td> <td> <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox> </td> <td> <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox> </td> <td> <asp:TextBox ID="TextBox4" runat="server"></asp:TextBox> </td> </tr> <tr> <td> </td> <td> </td> <td> </td> <td> <asp:Button ID="AddProduct" runat="server" Style="color: White" Text="Add Product" OnClick="AddProduct_Click" BackColor="#999966" /> </td> </tr> </table> <div style="margin-left:10px;margin-top:10px"> <asp:GridView ID="GridView1" AutoGenerateColumns="false" runat="server" CellPadding="4" ForeColor="#333333" GridLines="None"> <AlternatingRowStyle BackColor="White" /> <Columns> <asp:BoundField HeaderStyle-Width="120px" HeaderText="Author Name" DataField="AuthorName" /> <asp:BoundField HeaderStyle-Width="120px" HeaderText=" Book Name" DataField="BookName" /> <asp:BoundField HeaderStyle-Width="120px" HeaderText=" Book Type" DataField="BookType" /> <asp:BoundField HeaderStyle-Width="120px" HeaderText="Publisher" DataField="Publisher" /> </Columns> <EditRowStyle BackColor="#2461BF" /> <FooterStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" /> <HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" /> <PagerStyle BackColor="#2461BF" ForeColor="White" HorizontalAlign="Center" /> <RowStyle BackColor="#EFF3FB" /> <SelectedRowStyle BackColor="#D1DDF1" Font-Bold="True" ForeColor="#333333" /> <SortedAscendingCellStyle BackColor="#F5F7FB" /> <SortedAscendingHeaderStyle BackColor="#6D95E1" /> <SortedDescendingCellStyle BackColor="#E9EBEF" /> <SortedDescendingHeaderStyle BackColor="#4870BE" /> </asp:GridView> </div> </form> </body> </html>
Now switch to the default.aspx.cs code behind file and write
the following code to create and save the datatable into viewstate and
bind the GridView as:
private void AddDefaultFirstRecord() { //creating dataTable DataTable dt = new DataTable(); DataRow dr; dt.TableName = "AuthorBooks"; dt.Columns.Add(new DataColumn("AuthorName", typeof(string))); dt.Columns.Add(new DataColumn("BookName", typeof(string))); dt.Columns.Add(new DataColumn("BookType", typeof(string))); dt.Columns.Add(new DataColumn("Publisher", typeof(string))); dr = dt.NewRow(); dt.Rows.Add(dr); //saving databale into viewstate ViewState["AuthorBooks"] = dt; //bind Gridview GridView1.DataSource = dt; GridView1.DataBind(); }
Now call the above function at Page Load so that the initial records will be added into the view state and GridView as
protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { AddDefaultFirstRecord(); } }
Now create a method with the following code that will save the records
into a data table using view state and will be available to be bound to
the GridView as:
private void AddNewRecordRowToGrid() { // check view state is not null if (ViewState["AuthorBooks"] != null) { //get datatable from view state DataTable dtCurrentTable = (DataTable)ViewState["AuthorBooks"]; DataRow drCurrentRow = null; if (dtCurrentTable.Rows.Count > 0) { for (int i = 1; i <= dtCurrentTable.Rows.Count; i++) { //add each row into data table drCurrentRow = dtCurrentTable.NewRow(); drCurrentRow["AuthorName"] = TextBox1.Text; drCurrentRow["BrandName"] = TextBox2.Text; drCurrentRow["Warrenty"] =TextBox3.Text; drCurrentRow["Price"] =TextBox4.Text; } //Remove initial blank row if (dtCurrentTable.Rows[0][0].ToString() == "") { dtCurrentTable.Rows[0].Delete(); dtCurrentTable.AcceptChanges(); } //add created Rows into dataTable dtCurrentTable.Rows.Add(drCurrentRow); //Save Data table into view state after creating each row ViewState["AuthorBooks"] = dtCurrentTable; //Bind Gridview with latest Row GridView1.DataSource = dtCurrentTable; GridView1.DataBind(); } } }
Call the function above to add book details in the button click as:
protected void AddProduct_Click(object sender, EventArgs e) { AddNewRecordRowToGrid(); }
Now the entire code of the default.aspx.cs page will be such as follows:
using System; using System.Data; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { if (!IsPostBack) { AddDefaultFirstRecord(); } } protected void AddProduct_Click(object sender, EventArgs e) { AddNewRecordRowToGrid(); } private void AddDefaultFirstRecord() { //creating dataTable DataTable dt = new DataTable(); DataRow dr; dt.TableName = "AuthorBooks"; dt.Columns.Add(new DataColumn("AuthorName", typeof(string))); dt.Columns.Add(new DataColumn("BookName", typeof(string))); dt.Columns.Add(new DataColumn("BookType", typeof(string))); dt.Columns.Add(new DataColumn("Publisher", typeof(string))); dr = dt.NewRow(); dt.Rows.Add(dr); //saving databale into viewstate ViewState["AuthorBooks"] = dt; //bind Gridview GridView1.DataSource = dt; GridView1.DataBind(); } private void AddNewRecordRowToGrid() { // check view state is not null if (ViewState["AuthorBooks"] != null) { //get datatable from view state DataTable dtCurrentTable = (DataTable)ViewState["AuthorBooks"]; DataRow drCurrentRow = null; if (dtCurrentTable.Rows.Count > 0) { for (int i = 1; i <= dtCurrentTable.Rows.Count; i++) { //add each row into data table drCurrentRow = dtCurrentTable.NewRow(); drCurrentRow["AuthorName"] = TextBox1.Text; drCurrentRow["BookName"] = TextBox2.Text; drCurrentRow["BookType"] =TextBox3.Text; drCurrentRow["Publisher"] =TextBox4.Text; } //Remove initial blank row if (dtCurrentTable.Rows[0][0].ToString() == "") { dtCurrentTable.Rows[0].Delete(); dtCurrentTable.AcceptChanges(); } //add created Rows into dataTable dtCurrentTable.Rows.Add(drCurrentRow); //Save Data table into view state after creating each row ViewState["AuthorBooks"] = dtCurrentTable; //Bind Gridview with latest Row GridView1.DataSource = dtCurrentTable; GridView1.DataBind(); } } } }
Now run the application, the page will look as follows:
Now add some details into the textboxes above and click on the Add
Book Details button. Then the records that were saved in the DataTable
will displayed in the GridView as:
Now add another book details. It will be added in the existing one as:
Similar to the above you can add n number of records up to the data table capacity.
Note
- Do proper validation such as date input values when implementing.
Summary
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