System.InvalidCastException: Specified cast is not valid.

Hi
I get the this error when i run my code:
private void Page_Load(object sender, System.EventArgs e)
{
// Put user code to initialize the page here
this.DataGrid1.DataSource= this.DataSource();
this.DataGrid1.DataBind();
}
private ICollection DataSource()
{
DataTable dt = new DataTable();
dt.Columns.Add(new DataColumn("kol0",typeof(Int16)));
for (int i=0;i<10;i++)
{
DataRow dr = dt.NewRow();
if (i%2==0)
{
dr[0]=1;
}
else
{
dr[0]=0;
}
dt.Rows.Add(dr);
}
DataView dv;
dv = new DataView(dt);
return dv;
}
private void DataGrid1_ItemDataBound(object sender,
System.Web.UI.WebControls.DataGridItemEventArgs e)
{
int i = e.Item.ItemIndex;
if(i==0)
{
((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";
}
}
page:
one two
one two
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 96px; POSITION:
absolute; TOP: 56px" runat="server"
Height="216px" Width="448px" AutoGenerateColumns="False">
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<asp:DropDownList ID="dll" Runat="server">
<asp:ListItem Value="0">one</asp:ListItem>
<asp:ListItem Value="1">two</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
ch JIt would help if you told us the line #. Is it at:
((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";
First of all, it looks like you are doing that when ItemIndex == 0
wouldn't that be ur HeaderTemplate in which case cell[0].Controls[0]. really
might not be what you expect. Secondly, you might prefer
e.Item.FindControl("dll") or e.Item.Cells[0].FindContorl("dll") (not sure
which will work, favor the first one if it'll work) over using indexes. It
makes your code more flexible and less likely to break. Sometimes literals
(like spaces and newlines) are converted to controls, so while you might
think it's Controls[0], it might really be Controls[1] 'cuz there was a
newline before it.
It should be pretty easy to step through your code and debug though...
Karl
MY ASP.Net tutorials
http://www.openmymind.net/
http://openmymind.net/redirector.aspx?documentId=51 - Learn about AJAX!
"Jimmy" <beffer@.gmail.com> wrote in message
news:eX0b2r$yFHA.2556@.TK2MSFTNGP10.phx.gbl...
> Hi
> I get the this error when i run my code:
>
> private void Page_Load(object sender, System.EventArgs e)
> {
> // Put user code to initialize the page here
> this.DataGrid1.DataSource= this.DataSource();
> this.DataGrid1.DataBind();
> }
> private ICollection DataSource()
> {
> DataTable dt = new DataTable();
>
> dt.Columns.Add(new DataColumn("kol0",typeof(Int16)));
>
> for (int i=0;i<10;i++)
> {
> DataRow dr = dt.NewRow();
> if (i%2==0)
> {
> dr[0]=1;
>
> }
> else
> {
> dr[0]=0;
>
> }
> dt.Rows.Add(dr);
> }
> DataView dv;
> dv = new DataView(dt);
> return dv;
> }
> private void DataGrid1_ItemDataBound(object sender,
> System.Web.UI.WebControls.DataGridItemEventArgs e)
> {
> int i = e.Item.ItemIndex;
> if(i==0)
> {
> ((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";
> }
>
> }
>
> page:
>
> one two
> one two
> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 96px; POSITION:
> absolute; TOP: 56px" runat="server"
> Height="216px" Width="448px" AutoGenerateColumns="False">
> <Columns>
> <asp:TemplateColumn>
> <ItemTemplate>
> <asp:DropDownList ID="dll" Runat="server">
> <asp:ListItem Value="0">one</asp:ListItem>
> <asp:ListItem Value="1">two</asp:ListItem>
> </asp:DropDownList>
> </ItemTemplate>
> </asp:TemplateColumn>
> </Columns>
> </asp:DataGrid>
> ch J
>
>
>

System.InvalidCastException: Specified cast is not valid.

Hi

I get the this error when i run my code:

private void Page_Load(object sender, System.EventArgs e)

{

// Put user code to initialize the page here

this.DataGrid1.DataSource= this.DataSource();

this.DataGrid1.DataBind();

}

private ICollection DataSource()

{

DataTable dt = new DataTable();

dt.Columns.Add(new DataColumn("kol0",typeof(Int16)));

for (int i=0;i<10;i++)

{

DataRow dr = dt.NewRow();

if (i%2==0)

{

dr[0]=1;

}

else

{

dr[0]=0;

}

dt.Rows.Add(dr);

}

DataView dv;

dv = new DataView(dt);

return dv;

}

private void DataGrid1_ItemDataBound(object sender,
System.Web.UI.WebControls.DataGridItemEventArgs e)

{

int i = e.Item.ItemIndex;

if(i==0)

{

((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";

}

}

page:

one two
one two
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 96px; POSITION:
absolute; TOP: 56px" runat="server"
Height="216px" Width="448px" AutoGenerateColumns="False">
<Columns>
<asp:TemplateColumn>
<ItemTemplate>
<asp:DropDownList ID="dll" Runat="server">
<asp:ListItem Value="0">one</asp:ListItem>
<asp:ListItem Value="1">two</asp:ListItem>
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid
ch JIt would help if you told us the line #. Is it at:
((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";

First of all, it looks like you are doing that when ItemIndex == 0
wouldn't that be ur HeaderTemplate in which case cell[0].Controls[0]. really
might not be what you expect. Secondly, you might prefer
e.Item.FindControl("dll") or e.Item.Cells[0].FindContorl("dll") (not sure
which will work, favor the first one if it'll work) over using indexes. It
makes your code more flexible and less likely to break. Sometimes literals
(like spaces and newlines) are converted to controls, so while you might
think it's Controls[0], it might really be Controls[1] 'cuz there was a
newline before it.

It should be pretty easy to step through your code and debug though...

Karl

--
MY ASP.Net tutorials
http://www.openmymind.net/
http://openmymind.net/redirector.aspx?documentId=51 - Learn about AJAX!

"Jimmy" <beffer@.gmail.com> wrote in message
news:eX0b2r$yFHA.2556@.TK2MSFTNGP10.phx.gbl...
> Hi
> I get the this error when i run my code:
>
> private void Page_Load(object sender, System.EventArgs e)
> {
> // Put user code to initialize the page here
> this.DataGrid1.DataSource= this.DataSource();
> this.DataGrid1.DataBind();
> }
> private ICollection DataSource()
> {
> DataTable dt = new DataTable();
>
> dt.Columns.Add(new DataColumn("kol0",typeof(Int16)));
>
> for (int i=0;i<10;i++)
> {
> DataRow dr = dt.NewRow();
> if (i%2==0)
> {
> dr[0]=1;
>
> }
> else
> {
> dr[0]=0;
>
> }
> dt.Rows.Add(dr);
> }
> DataView dv;
> dv = new DataView(dt);
> return dv;
> }
> private void DataGrid1_ItemDataBound(object sender,
> System.Web.UI.WebControls.DataGridItemEventArgs e)
> {
> int i = e.Item.ItemIndex;
> if(i==0)
> {
> ((DropDownList)e.Item.Cells[0].Controls[0]).SelectedValue="one";
> }
>
> }
>
> page:
>
> one two
> one two
> <asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 96px; POSITION:
> absolute; TOP: 56px" runat="server"
> Height="216px" Width="448px" AutoGenerateColumns="False">
> <Columns>
> <asp:TemplateColumn>
> <ItemTemplate>
> <asp:DropDownList ID="dll" Runat="server">
> <asp:ListItem Value="0">one</asp:ListItem>
> <asp:ListItem Value="1">two</asp:ListItem>
> </asp:DropDownList>
> </ItemTemplate>
> </asp:TemplateColumn>
> </Columns>
> </asp:DataGrid>
> ch J
>
>

System.NullReferenceException: Object reference not set to an instance of an object.

Hi, the following code received run-time error (NullReferenceException), and I don't know how to troubleshoot it :(
under Page_Load at Default.aspx:

loginBox.LoginAuthenticated += new LoginAuthenticatedEventHandler(Succeeded)

under my LoginBox.ascx.cs, I setup the object like the followings:
public delegate void LoginAuthenticatedEventHandler(object sender, LoginAuthenticatedEventArgs e);
public event LoginAuthenticatedEventHandler LoginAuthenticated;
public class LoginAuthenticatedEventArgs : EventArgs
{
public int UsrID;
}//end class LoginAuthenticatedEventArgs

under my Page_Load of my LoginBox.ascx.cs, I load my object like this:
if (LoginAuthenticated != null)
{
LoginAuthenticatedEventArgs eventInfo = new LoginAuthenticatedEventArgs();
eventInfo.UsrID = Int32.Parse(txtUser.Text);
LoginAuthenticated(Page, eventInfo);
}//end if (LoginAuthenticated != null)

I thought I had the object reference to the correct place, what else am I missing?
TIA
..resoloved: http://forums.asp.net/1089126/ShowPost.aspx

System.Threading.ThreadAbortException and Response.Redirect

I have an ASP.net 2.0 app on a W2K3 box. I am using Response.Redirect inside page_load. After reading a bunch of posts, I've tried setting the second arg to false, but still get the error. I've also tried moving the redirect outside the try block. No love. I catch and ignore the error, but the redirect doesn't redirect to the new url.

All worked fine until this started happening out of the blue.

Thanks.

I assume you meant to post your code... but you forgot. Can you post your problem code please?

oops. Sorry.

If Request.QueryString("testnum") Is Nothing Then
Response.Redirect("http://localhost:10607/WWW/testing.aspx?testnum=1.11-.01-C1-T1&ucid=0")

End if

Have you tried using a relative URL, instead of an absolute URL?

The thing is, the built in web server in Visual Studio (Cassini) uses dynamic port assignment. Therefore, there is no guarantee (in fact no likelihood at all) that the port used will be the same every time.

Try a URL of"~/testing.aspx?testnum=1.11-.01-C1-T1&ucid=0"