I am trying to set the value of "dt" of redirect url
"http://127.0.0.1/HOG/HOG_reporting_Rly.aspx?Monday=Y&Zrly=CR&dt=01-Apr-19"
in text box of GridView on another page for updating the data source. But it gives error
Object reference not set to an instance of an object. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
My code is as under:
<%@ Page Language="C#" %>
<!DOCTYPE html>
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
if (!Page.IsPostBack)
{
if (Request.QueryString["dt"] != null)
{
foreach (GridViewRow gvr in GridView1.Rows)
{
TextBox tb = (TextBox)gvr.FindControl("TextBox17");
tb.Text = Request.QueryString["dt"];
}
}
}
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
<style type="text/css">
.auto-style1 {
text-align: center;
}
.auto-style2 {
font-family: Tahoma;
font-size: medium;
color: #990000;
font-weight: bold;
}
</style>
</head>
<body>
<form id="form1" runat="server">
<div class="auto-style1">
<span class="auto-style2">HOG Train Master (List of All HOG Trains)</span><br class="auto-style2" />
</div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ID" DataSourceID="SqlDataSource1"
HorizontalAlign="Center" Font-Names="Tahoma" Font-Size="Small" AllowSorting="True" >
<Columns>
<asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" ReadOnly="True" SortExpression="ID" />
<asp:TemplateField HeaderText="Zrly" SortExpression="Zrly">
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("Zrly") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Zrly") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco_req" SortExpression="Loco_req">
<EditItemTemplate>
<asp:TextBox ID="TextBox2" runat="server" Text='<%# Bind("Loco_req") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label2" runat="server" Text='<%# Bind("Loco_req") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Train" SortExpression="Train">
<EditItemTemplate>
<asp:TextBox ID="TextBox3" runat="server" Text='<%# Bind("Train") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label3" runat="server" Text='<%# Bind("Train") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Origin" SortExpression="Origin">
<EditItemTemplate>
<asp:TextBox ID="TextBox4" runat="server" Text='<%# Bind("Origin") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label4" runat="server" Text='<%# Bind("Origin") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Destin" SortExpression="Destin">
<EditItemTemplate>
<asp:TextBox ID="TextBox5" runat="server" Text='<%# Bind("Destin") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label5" runat="server" Text='<%# Bind("Destin") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Rake_link" SortExpression="Rake_link">
<EditItemTemplate>
<asp:TextBox ID="TextBox6" runat="server" Text='<%# Bind("Rake_link") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label6" runat="server" Text='<%# Bind("Rake_link") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco_link" SortExpression="Loco_link">
<EditItemTemplate>
<asp:TextBox ID="TextBox7" runat="server" Text='<%# Bind("Loco_link") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label7" runat="server" Text='<%# Bind("Loco_link") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Saturday" SortExpression="Saturday">
<EditItemTemplate>
<asp:TextBox ID="TextBox8" runat="server" Text='<%# Bind("Saturday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label8" runat="server" Text='<%# Bind("Saturday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Friday" SortExpression="Friday">
<EditItemTemplate>
<asp:TextBox ID="TextBox9" runat="server" Text='<%# Bind("Friday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label9" runat="server" Text='<%# Bind("Friday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Thursday" SortExpression="Thursday">
<EditItemTemplate>
<asp:TextBox ID="TextBox10" runat="server" Text='<%# Bind("Thursday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label10" runat="server" Text='<%# Bind("Thursday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Wednesday" SortExpression="Wednesday">
<EditItemTemplate>
<asp:TextBox ID="TextBox11" runat="server" Text='<%# Bind("Wednesday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label11" runat="server" Text='<%# Bind("Wednesday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Tuesday" SortExpression="Tuesday">
<EditItemTemplate>
<asp:TextBox ID="TextBox12" runat="server" Text='<%# Bind("Tuesday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label12" runat="server" Text='<%# Bind("Tuesday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Monday" SortExpression="Monday">
<EditItemTemplate>
<asp:TextBox ID="TextBox13" runat="server" Text='<%# Bind("Monday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label13" runat="server" Text='<%# Bind("Monday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Sunday" SortExpression="Sunday">
<EditItemTemplate>
<asp:TextBox ID="TextBox14" runat="server" Text='<%# Bind("Sunday") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label14" runat="server" Text='<%# Bind("Sunday") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco_no" SortExpression="Loco_no">
<EditItemTemplate>
<asp:TextBox ID="TextBox15" runat="server" Text='<%# Bind("Loco_no") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label15" runat="server" Text='<%# Bind("Loco_no") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Loco_type" SortExpression="Loco_type">
<EditItemTemplate>
<asp:TextBox ID="TextBox16" runat="server" Text='<%# Bind("Loco_type") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label16" runat="server" Text='<%# Bind("Loco_type") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="updated_on" SortExpression="updated_on">
<EditItemTemplate>
<asp:TextBox ID="TextBox17" runat="server" Text='<%# Bind("updated_on") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label17" runat="server" Text='<%# Bind("updated_on") %>'></asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowEditButton="True" />
</Columns>
<HeaderStyle HorizontalAlign="Center" VerticalAlign="Middle" />
<RowStyle Font-Names="Tahoma" Font-Size="Small" HorizontalAlign="Center" VerticalAlign="Middle" Wrap="False" />
</asp:GridView>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" CancelSelectOnNullParameter="false"
ConnectionString="<%$ ConnectionStrings:Loco_bankConnectionString %>"
DeleteCommand="DELETE FROM [Hotel_load] WHERE [ID] = @ID"
InsertCommand="INSERT INTO [Hotel_load] ([Zrly], [Loco_req], [Train], [Origin], [Destin], [Rake_link], [Loco_link], [Saturday], [Friday], [Thursday], [Wednesday], [Tuesday], [Monday], [Sunday], [Loco_no], [Loco_type], [updated_on]) VALUES (@Zrly, @Loco_req, @Train, @Origin, @Destin, @Rake_link, @Loco_link, @Saturday, @Friday, @Thursday, @Wednesday, @Tuesday, @Monday, @Sunday, @Loco_no, @Loco_type, @updated_on)"
SelectCommand="SELECT [ID], [Zrly], [Loco_req], [Train], [Origin], [Destin], [Rake_link], [Loco_link], [Saturday], [Friday], [Thursday], [Wednesday], [Tuesday], [Monday], [Sunday], [Loco_no], [Loco_type], [updated_on] FROM [Hotel_load] WHERE ([Saturday] = @Saturday OR @Saturday IS NULL) AND ([Sunday] = @Sunday OR @Sunday IS NULL) AND ([Monday] = @Monday OR @Monday IS NULL) AND ([Tuesday] = @Tuesday OR @Tuesday IS NULL) AND ([Wednesday] = @Wednesday OR @Wednesday IS NULL) AND ([Thursday] = @Thursday OR @Thursday IS NULL) AND ([Friday] = @Friday OR @Friday IS NULL) AND ([Zrly] = @Zrly) "
UpdateCommand="UPDATE [Hotel_load] SET [Zrly] = @Zrly, [Loco_req] = @Loco_req, [Train] = @Train, [Origin] = @Origin, [Destin] = @Destin, [Rake_link] = @Rake_link, [Loco_link] = @Loco_link, [Saturday] = @Saturday, [Friday] = @Friday, [Thursday] = @Thursday, [Wednesday] = @Wednesday, [Tuesday] = @Tuesday, [Monday] = @Monday, [Sunday] = @Sunday, [Loco_no] = @Loco_no, [Loco_type] = @Loco_type, [updated_on] = @updated_on WHERE [ID] = @ID">
<DeleteParameters>
<asp:Parameter Name="ID" Type="Int32" />
</DeleteParameters>
<InsertParameters>
<asp:Parameter Name="Zrly" Type="String" />
<asp:Parameter Name="Loco_req" Type="String" />
<asp:Parameter Name="Train" Type="String" />
<asp:Parameter Name="Origin" Type="String" />
<asp:Parameter Name="Destin" Type="String" />
<asp:Parameter Name="Rake_link" Type="String" />
<asp:Parameter Name="Loco_link" Type="String" />
<asp:Parameter Name="Saturday" Type="String" />
<asp:Parameter Name="Friday" Type="String" />
<asp:Parameter Name="Thursday" Type="String" />
<asp:Parameter Name="Wednesday" Type="String" />
<asp:Parameter Name="Tuesday" Type="String" />
<asp:Parameter Name="Monday" Type="String" />
<asp:Parameter Name="Sunday" Type="String" />
<asp:Parameter Name="Loco_no" Type="String" />
<asp:Parameter Name="Loco_type" Type="String" />
<asp:Parameter Name="updated_on" Type="DateTime" />
</InsertParameters>
<SelectParameters>
<asp:QueryStringParameter Name="Saturday" QueryStringField="Saturday" Type="String" />
<asp:QueryStringParameter Name="Sunday" QueryStringField="Sunday" Type="String" />
<asp:QueryStringParameter Name="Monday" QueryStringField="Monday" Type="String" />
<asp:QueryStringParameter Name="Tuesday" QueryStringField="Tuesday" Type="String" />
<asp:QueryStringParameter Name="Wednesday" QueryStringField="Wednesday" Type="String" />
<asp:QueryStringParameter Name="Thursday" QueryStringField="Thursday" Type="String" />
<asp:QueryStringParameter Name="Friday" QueryStringField="Friday" Type="String" />
<asp:QueryStringParameter Name="Zrly" QueryStringField="Zrly" Type="String" />
</SelectParameters>
<UpdateParameters>
<asp:Parameter Name="Zrly" Type="String" />
<asp:Parameter Name="Loco_req" Type="String" />
<asp:Parameter Name="Train" Type="String" />
<asp:Parameter Name="Origin" Type="String" />
<asp:Parameter Name="Destin" Type="String" />
<asp:Parameter Name="Rake_link" Type="String" />
<asp:Parameter Name="Loco_link" Type="String" />
<asp:Parameter Name="Saturday" Type="String" />
<asp:Parameter Name="Friday" Type="String" />
<asp:Parameter Name="Thursday" Type="String" />
<asp:Parameter Name="Wednesday" Type="String" />
<asp:Parameter Name="Tuesday" Type="String" />
<asp:Parameter Name="Monday" Type="String" />
<asp:Parameter Name="Sunday" Type="String" />
<asp:Parameter Name="Loco_no" Type="String" />
<asp:Parameter Name="Loco_type" Type="String" />
<asp:Parameter Name="updated_on" Type="DateTime" />
<asp:Parameter Name="ID" Type="Int32" />
</UpdateParameters>
</asp:SqlDataSource>
</form>
</body>
</html>
What I have tried:
Tried a lot of googling and examples but nothing works for me.