A safe array of bytes is expected as an argument

[Dooza]

Hi there,
I am using the ASP to PDF component from www.asppdf.com and have an
unusual problem when displaying a blob from the database.

When there is an image stored in my SQL2000 field of type image, and I
use this:

Params = "x=337; y=408; scalex=.33; scaley=.33"
Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
Page.Canvas.Dra wImage SigImage, Params

The image gets drawn in the PDF and everything is fine.

If I try to create a PDF using the same record, but where the image
filed is NULL, I get this error:

Persits.PdfMana ger.1 error '800a002f'

A safe array of bytes is expected as an argument.

So I thought I need to check if the field isn't null before attempting
to draw it onto the canvas, so I tried this:

If LEN(rsMotor("Ph oto").Value) 0 Then
'Insert Photo
Params = "x=337; y=408; scalex=.33; scaley=.33"
Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
Page.Canvas.Dra wImage SigImage, Params
End if

Using this with an image stored in the field gives me the same error
message, its only when the field is empty that the above code works and
doesn't draw the image on the PDF.

I also tried this:

If NOT(ISNULL(rsMo tor("Photo").Va lue)) Then
'Insert Photo
Params = "x=337; y=408; scalex=.33; scaley=.33"
Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
Page.Canvas.Dra wImage SigImage, Params
End if

But still got the same error.

If I don't use any checking code, and have NULL in the image field, I
get the same error. This must be something to do with the binary
content, how can I detect if there is binary content?

Steve

[Jon Paal [MSMD]]

Re: A safe array of bytes is expected as an argument

http://databases.aspfaq.com/database/how-do-i-prevent-nulls-in-my-database-from-mucking-up-my-html.html

http://databases.aspfaq.com/database/coalesce-vs-isnull-sql.html

[Dooza]

Re: A safe array of bytes is expected as an argument

Jon Paal [MSMD] wrote:

http://databases.aspfaq.com/database/how-do-i-prevent-nulls-in-my-database-from-mucking-up-my-html.html

>
http://databases.aspfaq.com/database...snull-sql.html

Hi Jon,
Thanks for the pointers, I like the idea of doing it in SQL, as I am
already using a view to get the data to the page.

I am still open to other ideas.

Cheers,

Steve

[Dooza]

Re: A safe array of bytes is expected as an argument

Dooza wrote:

Jon Paal [MSMD] wrote:

>http://databases.aspfaq.com/database...p-my-html.html
>>
>>
>http://databases.aspfaq.com/database...snull-sql.html

>
Hi Jon,
Thanks for the pointers, I like the idea of doing it in SQL, as I am
already using a view to get the data to the page.
>
I am still open to other ideas.
>
Cheers,
>
Steve

I have gone for a temporary solution, as it seems that as soon as you do
a length check or isnull check on the binary field it becomes unusable.

I have used this in my SQL view:

CASE WHEN (MC.mct_photo IS NULL)
THEN '0' ELSE '1' END AS PhotoCheck

And this on my page:

If rsMotor("PhotoC heck") = 1 Then
'Insert Photo
Params = "x=337; y=408; scalex=.33; scaley=.33"
Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
Page.Canvas.Dra wImage SigImage, Params
End if

Does anyone have any experience with using binary data in asp? Am I
right in thinking that the starting position has changed due to the
length check? Is there a way to reset the starting position?

Cheers,

Steve

[Dave Anderson]

Re: A safe array of bytes is expected as an argument

Dooza wrote:

I have gone for a temporary solution, as it seems that as soon as you
do a length check or isnull check on the binary field it becomes
unusable.
I have used this in my SQL view:
>
CASE WHEN (MC.mct_photo IS NULL)
THEN '0' ELSE '1' END AS PhotoCheck
>
And this on my page:
>
If rsMotor("PhotoC heck") = 1 Then
'Insert Photo
Params = "x=337; y=408; scalex=.33; scaley=.33"
Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
Page.Canvas.Dra wImage SigImage, Params
End if
>
Does anyone have any experience with using binary data in asp? Am I
right in thinking that the starting position has changed due to the
length check? Is there a way to reset the starting position?

Rather than checking for NULL, use DATALENGTH:
http://msdn2.microsoft.com/en-us/library/ms173486.aspx




--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message. Use
of this email address implies consent to these terms.

[Dooza]

Re: A safe array of bytes is expected as an argument

Dave Anderson wrote:

Dooza wrote:

>I have gone for a temporary solution, as it seems that as soon as you
>do a length check or isnull check on the binary field it becomes
>unusable.
>I have used this in my SQL view:
>>
>CASE WHEN (MC.mct_photo IS NULL)
> THEN '0' ELSE '1' END AS PhotoCheck
>>
>And this on my page:
>>
>If rsMotor("PhotoC heck") = 1 Then
>'Insert Photo
>Params = "x=337; y=408; scalex=.33; scaley=.33"
>Set SigImage = Doc.OpenImageBi nary(rsMotor("P hoto").Value)
>Page.Canvas.Dr awImage SigImage, Params
>End if
>>
>Does anyone have any experience with using binary data in asp? Am I
>right in thinking that the starting position has changed due to the
>length check? Is there a way to reset the starting position?

>
Rather than checking for NULL, use DATALENGTH:
http://msdn2.microsoft.com/en-us/library/ms173486.aspx

Hi Dave, thats a new one on me, is it SQL only, or can I use it in
ASP/VBScript?

Steve

[Dave Anderson]

Re: A safe array of bytes is expected as an argument

Dooza wrote:

>>CASE WHEN (MC.mct_photo IS NULL)
>> THEN '0' ELSE '1' END AS PhotoCheck

>>
>Rather than checking for NULL, use DATALENGTH:
>http://msdn2.microsoft.com/en-us/library/ms173486.aspx

>
Hi Dave, thats a new one on me, is it SQL only, or can I use
it in ASP/VBScript?

It's only VBScript if you can find it here:
http://msdn2.microsoft.com/en-us/library/d1wf56tt.aspx

The link I provided is Transact-SQL. I meant for you to understand that you
can use it in this manner:

SELECT
MC.mct_photo,
DATALENGTH(MC.m ct_photo) AS Bytes,
...
FROM [Your Table]

This does not require a conditional evaluation in the database. You will be
using one, regardless, in your web script, so why add another?



--
Dave Anderson

Unsolicited commercial email will be read at a cost of $500 per message. Use
of this email address implies consent to these terms.

[Dooza]

Re: A safe array of bytes is expected as an argument

Dave Anderson wrote:

The link I provided is Transact-SQL. I meant for you to understand

that you

can use it in this manner:
>
SELECT
MC.mct_photo,
DATALENGTH(MC.m ct_photo) AS Bytes,
...
FROM [Your Table]
>
This does not require a conditional evaluation in the database. You

will be

using one, regardless, in your web script, so why add another?

That makes perfect sense and works perfectly too. It will also allow me
to keep an eye on the size of images in the table.

Thanks again!

Steve