Error: specified cast is not valid. Why not?

[Alan Silver]

Hello,

I have an ASP.NET page where I am grabbing an SqlDataReader and using it
to populate some controls on the form. Amongst the fields pulled out of
the table are two integer fields, which I am trying to cast as strings
so they can be displayed in a Literal control.

I am using the following code (heavily edited for clarity) ...

if (dtrDilemmas.Re ad()) {
litDilCurrentYe sNo.Text = (String)dtrDile mmas["CurrentYes "] + "
votes yes and " + (String)dtrDile mmas["CurrentNo"] + " votes no";
}

where dtrDilemmas is the SqlDataReader that contains just one record. In
that record are two fields, CurrentYes and CurrentNo, which are both
integers. I have other (varchar) fields which I can use just fine. When
it hits the line shown above, I get the error "specified cast is not
valid".

Anyone any idea why not and how I fix it? TIA

--
Alan Silver
(anything added below this line is nothing to do with me)

[Elton Wang]

Try

litDilCurrentYe sNo.Text = ((int)dtrDilemm as
["CurrentYes "]).Tostring() + "votes yes and " + ((int)
dtrDilemmas["CurrentNo"]).Tostring() + " votes no";

HTH,

Elton Wang
el*******@hotma il.com

-----Original Message-----
Hello,

I have an ASP.NET page where I am grabbing an SqlDataReader and using itto populate some controls on the form. Amongst the fields pulled out ofthe table are two integer fields, which I am trying to cast as stringsso they can be displayed in a Literal control.

I am using the following code (heavily edited for clarity) ...
if (dtrDilemmas.Re ad()) {
litDilCurrentYe sNo.Text = (String)dtrDile mmas ["CurrentYes "] + "votes yes and " + (String)dtrDile mmas["CurrentNo"] + " votes no"; }

where dtrDilemmas is the SqlDataReader that contains just one record. Inthat record are two fields, CurrentYes and CurrentNo, which are bothintegers. I have other (varchar) fields which I can use just fine. Whenit hits the line shown above, I get the error "specified cast is notvalid".

Anyone any idea why not and how I fix it? TIA

--
Alan Silver
(anything added below this line is nothing to do with me)
.

[Kevin Spencer]

You can't cast the object as a string because it isn't a string. However,
you can use the DataReader's methods to get the string out of it, such as
GetString(). Example:

litDilCurrentYe sNo.Text =
dtrDilemmas.Get String(dtrDilem mas.GetOrdinal( "CurrentYes ")) ...

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.

"Alan Silver" <al*********@no spam.thanx> wrote in message
news:tv******** ******@nospamth ankyou.spam...

Hello,

I have an ASP.NET page where I am grabbing an SqlDataReader and using it
to populate some controls on the form. Amongst the fields pulled out of
the table are two integer fields, which I am trying to cast as strings
so they can be displayed in a Literal control.

I am using the following code (heavily edited for clarity) ...

if (dtrDilemmas.Re ad()) {
litDilCurrentYe sNo.Text = (String)dtrDile mmas["CurrentYes "] + "
votes yes and " + (String)dtrDile mmas["CurrentNo"] + " votes no";
}

where dtrDilemmas is the SqlDataReader that contains just one record. In
that record are two fields, CurrentYes and CurrentNo, which are both
integers. I have other (varchar) fields which I can use just fine. When
it hits the line shown above, I get the error "specified cast is not
valid".

Anyone any idea why not and how I fix it? TIA

--
Alan Silver
(anything added below this line is nothing to do with me)

[Alan Silver]

Thanks to both of you. It's obvious now, but it needed pointing out ;-)

Try

litDilCurrentY esNo.Text = ((int)dtrDilemm as
["CurrentYes "]).Tostring() + "votes yes and " + ((int)
dtrDilemmas["CurrentNo"]).Tostring() + " votes no";

HTH,

Elton Wang
el*******@hotm ail.com

-----Original Message-----
Hello,

I have an ASP.NET page where I am grabbing an

SqlDataReade r and using it

to populate some controls on the form. Amongst the fields

pulled out of

the table are two integer fields, which I am trying to

cast as strings

so they can be displayed in a Literal control.

I am using the following code (heavily edited for

clarity) ...

if (dtrDilemmas.Re ad()) {
litDilCurrentYe sNo.Text = (String)dtrDile mmas

["CurrentYes "] + "

votes yes and " + (String)dtrDile mmas["CurrentNo"] + "

votes no";

}

where dtrDilemmas is the SqlDataReader that contains just

one record. In

that record are two fields, CurrentYes and CurrentNo,

which are both

integers. I have other (varchar) fields which I can use

just fine. When

it hits the line shown above, I get the error "specified

cast is not

valid".

Anyone any idea why not and how I fix it? TIA

--
Alan Silver
(anything added below this line is nothing to do with me)
.

--
Alan Silver
(anything added below this line is nothing to do with me)

[Tampa .NET Koder]

Really, I thought you were able to downcast from Object to String since
string inherits from Object. Can you shed some light on this subject for the
benefit of all?

"Kevin Spencer" wrote:

You can't cast the object as a string because it isn't a string. However,
you can use the DataReader's methods to get the string out of it, such as
GetString(). Example:

litDilCurrentYe sNo.Text =
dtrDilemmas.Get String(dtrDilem mas.GetOrdinal( "CurrentYes ")) ...

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.

"Alan Silver" <al*********@no spam.thanx> wrote in message
news:tv******** ******@nospamth ankyou.spam...

Hello,

I have an ASP.NET page where I am grabbing an SqlDataReader and using it
to populate some controls on the form. Amongst the fields pulled out of
the table are two integer fields, which I am trying to cast as strings
so they can be displayed in a Literal control.

I am using the following code (heavily edited for clarity) ...

if (dtrDilemmas.Re ad()) {
litDilCurrentYe sNo.Text = (String)dtrDile mmas["CurrentYes "] + "
votes yes and " + (String)dtrDile mmas["CurrentNo"] + " votes no";
}

where dtrDilemmas is the SqlDataReader that contains just one record. In
that record are two fields, CurrentYes and CurrentNo, which are both
integers. I have other (varchar) fields which I can use just fine. When
it hits the line shown above, I get the error "specified cast is not
valid".

Anyone any idea why not and how I fix it? TIA

--
Alan Silver
(anything added below this line is nothing to do with me)

[Kevin Spencer]

You can cast anything to a string that IS a string. For example, if you use
object (generally not a good idea), you can store ANY kind of object in it.
So, let's say that the object contains a number. Could you cast it as a
string? No. You would have to Convert it to a string. This can be done using
the .ToString() method, or Convert.ToStrin g().

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.

"Tampa .NET Koder" <Ta***********@ discussions.mic rosoft.com> wrote in
message news:0F******** *************** ***********@mic rosoft.com...

Really, I thought you were able to downcast from Object to String since
string inherits from Object. Can you shed some light on this subject for
the
benefit of all?

"Kevin Spencer" wrote:

You can't cast the object as a string because it isn't a string. However,
you can use the DataReader's methods to get the string out of it, such as
GetString(). Example:

litDilCurrentYe sNo.Text =
dtrDilemmas.Get String(dtrDilem mas.GetOrdinal( "CurrentYes ")) ...

--
HTH,

Kevin Spencer
Microsoft MVP
..Net Developer
Neither a follower nor a lender be.

"Alan Silver" <al*********@no spam.thanx> wrote in message
news:tv******** ******@nospamth ankyou.spam...

> Hello,
>
> I have an ASP.NET page where I am grabbing an SqlDataReader and using
> it
> to populate some controls on the form. Amongst the fields pulled out of
> the table are two integer fields, which I am trying to cast as strings
> so they can be displayed in a Literal control.
>
> I am using the following code (heavily edited for clarity) ...
>
> if (dtrDilemmas.Re ad()) {
> litDilCurrentYe sNo.Text = (String)dtrDile mmas["CurrentYes "] + "
> votes yes and " + (String)dtrDile mmas["CurrentNo"] + " votes no";
> }
>
> where dtrDilemmas is the SqlDataReader that contains just one record.
> In
> that record are two fields, CurrentYes and CurrentNo, which are both
> integers. I have other (varchar) fields which I can use just fine. When
> it hits the line shown above, I get the error "specified cast is not
> valid".
>
> Anyone any idea why not and how I fix it? TIA
>
> --
> Alan Silver
> (anything added below this line is nothing to do with me)