User-369506445 posted
hi
you can set true the AutoPostBack in your drop-down list and fill your grid view in OnSelectedIndexChanged
I create a sample that show how do you do it, please first try my sample in a new project and if was correct the change to your needs
in code behind
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Session["GridDataTable"] = null;
FillDropDown();
}
}
protected void ddl_OnSelectedIndexChanged(object sender, EventArgs e)
{
string text = ddl.SelectedItem.Text;
var dt = getSearchItems(text);
if (Session["GridDataTable"] == null)
{
Session["GridDataTable"] = dt;
grd.DataSource = dt;
grd.DataBind();
return;
}
DataTable lastDataTable = (DataTable)Session["GridDataTable"];
lastDataTable.Merge(dt);
DataTable distinctTable = lastDataTable.DefaultView.ToTable( /*distinct*/ true);
Session["GridDataTable"] = distinctTable;
grd.DataSource =Session["GridDataTable"];
grd.DataBind();
}
void FillDropDown()
{
const string query = "select distinct [ItemName] from yourTable";
using (var con = new SqlConnection(ConnectionString))
{
con.Open();
using (var com = new SqlCommand(query, con))
{
SqlDataReader sdrselect = com.ExecuteReader();
ddl.DataTextField = "ItemName";
ddl.DataValueField = "ItemName";
ddl.DataSource = sdrselect;
ddl.DataBind();
}
}
}
DataTable getSearchItems(string param)
{
string query = "select * from yourTable where ItemName='" + param + "'";
using (var con = new SqlConnection(ConnectionString))
{
con.Open();
using (var com = new SqlCommand(query, con))
{
using (SqlDataReader dr = com.ExecuteReader())
{
var tb = new DataTable();
tb.Load(dr);
return tb;
}
}
}
}
and in Html
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head >
</head>
<body>
<form id="form1" runat="server">
<asp:DropDownList runat="server" ID="ddl" AutoPostBack="true" OnSelectedIndexChanged="ddl_OnSelectedIndexChanged" />
<asp:GridView ID="grd" runat="server" AutoGenerateColumns="False">
<Columns>
<asp:TemplateField HeaderText="ItemName">
<ItemTemplate>
<asp:Label ID="lblItemName" runat="server" Text='<%#Eval("ItemName") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="BelongsTo">
<ItemTemplate>
<asp:Label ID="lblBelongsTo" runat="server" Text='<%#Eval("BelongsTo") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Qty">
<ItemTemplate>
<asp:Label ID="lblQty" runat="server" Text='<%#Eval("Qty") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</form>
</body>
</html>
I hope it can be helpful
