I am trying to make a simple library database. I list the search results in a gridview, then i have a textbox and a button, user enters the isbn and clicks loan button. Then, if there is enough number of items (itemNumber>0) it is loaned by user. Here is the screenshot of user interface:
My question is, when user clicks loan button the loan may or may not be succesful. In both cases, i print a message indicating whether loan is succesful or not, and i also want the updated gridview to be displayed. The problem is, after pressing the loan button the gridview disappears and i just see the textbox, button and the message on the screen. How can i show the updated version of gridview after pressing loan button?
Here is the code file:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="SearchResults.aspx.cs" Inherits="Pages_SearchResults" %>
<!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>
<form id="form1" runat="server">
<div>
</div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
DataKeyNames="ISBN" DataSourceID="SqlDataSource1"
onselectedindexchanged="GridView1_SelectedIndexChanged"
onrowcommand="GridView1_RowCommand">
<Columns>
<asp:BoundField DataField="Title" HeaderText="Title" SortExpression="Title" />
<asp:BoundField DataField="ISBN" HeaderText="ISBN" ReadOnly="True"
SortExpression="ISBN" />
<asp:BoundField DataField="AuthorName" HeaderText="AuthorName"
SortExpression="AuthorName" />
<asp:BoundField DataField="AuthorlName" HeaderText="AuthorlName"
SortExpression="AuthorlName" />
<asp:BoundField DataField="ItemType" HeaderText="ItemType"
SortExpression="ItemType" />
<asp:BoundField DataField="PublishYear" HeaderText="PublishYear"
SortExpression="PublishYear" />
<asp:BoundField DataField="numOfCopies" HeaderText="Number of Copies"
SortExpression="numOfCopies" />
</Columns>
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ ConnectionStrings:ConnectionString %>"
SelectCommand="SELECT * FROM [Items] WHERE ([Title] LIKE '%' + @Title + '%')">
<SelectParameters>
<asp:FormParameter FormField="tSearchBox" Name="Title" Type="String" />
</SelectParameters>
</asp:SqlDataSource>
<br />
<asp:Label ID="Label1" runat="server" Text="Type ISBN to loan:"></asp:Label>
And here is the .cs file:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
public partial class Pages_SearchResults : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void GridView1_SelectedIndexChanged(object sender, EventArgs e)
{
Response.Redirect("Default.aspx");
}
protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=D:\\Users\\SUUSER\\Documents\\Visual Studio 2010\\Projects\\Library\\LibWebSite\\App_Data\\LibDatabase.mdf;Integrated Security=True;User Instance=True";
Int32 verify;
string title = GridView1.HeaderRow.Cells[0].Text, isbn = GridView1.HeaderRow.Cells[1].Text, name = GridView1.HeaderRow.Cells[2].Text, lname = GridView1.HeaderRow.Cells[3].Text, type = GridView1.HeaderRow.Cells[4].Text, year = GridView1.HeaderRow.Cells[5].Text;
}
protected void bLoanButton_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=D:\\Users\\SUUSER\\Documents\\Visual Studio 2010\\Projects\\Library\\LibWebSite\\App_Data\\LibDatabase.mdf;Integrated Security=True;User Instance=True";
string user = "select CurrentID from CurrentUser";
SqlCommand cmd1 = new SqlCommand(user, con);
con.Open();
string get = cmd1.ExecuteScalar().ToString();
string query1 = "insert into LoanTable(StudId,ISBN,onBorrow) values ("
+ "'" + get + "'" + "," + "'" + tLoanBox.Text + "'" + ","
+ "'" + "1" + "'" + ")";
string numQuery = "select numOfCopies from Items where ISBN='" + tLoanBox.Text + "'";
SqlCommand cmdnumQuery = new SqlCommand(numQuery, con);
SqlCommand cmd2 = new SqlCommand(query1, con);
int result;
int num=Convert.ToInt32(cmdnumQuery.ExecuteScalar());
result = cmd2.ExecuteNonQuery();
if (num > 0)
{
if (result > 0)
Response.Redirect("LoanSuccesfull.aspx");
}
else
notAvailable.Visible = true;
con.Close();
}
}
And here is the code for loan button:
protected void bLoanButton_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
con.ConnectionString = "Data Source=.\\SQLEXPRESS;AttachDbFilename=D:\\Users\\SUUSER\\Documents\\Visual Studio 2010\\Projects\\Library\\LibWebSite\\App_Data\\LibDatabase.mdf;Integrated Security=True;User Instance=True";
string user = "select CurrentID from CurrentUser";
SqlCommand cmd1 = new SqlCommand(user, con);
con.Open();
string get = cmd1.ExecuteScalar().ToString();
string query1 = "insert into LoanTable(StudId,ISBN,onBorrow) values ("
+ "'" + get + "'" + "," + "'" + tLoanBox.Text + "'" + ","
+ "'" + "1" + "'" + ")";
SqlCommand cmd2 = new SqlCommand(query1, con);
int result;
result = cmd2.ExecuteNonQuery();
if (result > 0)
{
loanSuccesful.Visible = true;
Response.Redirect("LoanSuccesfull.aspx");
}
con.Close();
}
I appreciate any help. Thanks
The answer is
Before data bind change gridview databinding method, assign GridView.EditIndex to -1. It solved the same issue for me :
gvTypes.EditIndex = -1;
gvTypes.DataBind();
gvTypes is my GridView ID.
I was totally lost on why my Gridview.Databind() would not refresh.
My issue, I discovered, was my gridview was inside a UpdatePanel. To get my GridView to FINALLY refresh was this:
gvServerConfiguration.Databind()
uppServerConfiguration.Update()
uppServerConfiguration is the id associated with my UpdatePanel in my asp.net code.
Hope this helps someone.
Adding the GridView1.DataBind() to the button click event did not work for me. However, adding it to the SqlDataSource1_Updated event did though.
Protected Sub SqlDataSource1_Updated(sender As Object, e As SqlDataSourceStatusEventArgs) Handles SqlDataSource1.Updated
GridView1.DataBind()
End Sub
Source: Stackoverflow.com