I have one image file. (C: \ temp \ image1.jpg)
I have one catalog.
The name of the image area in my catalog [ImageField].
...
-Code
-desc
-name
-imagefield
...

How can I store the file?
Do you have sample code?

You used 'Managed applicationor' Or 'ordinary application' ?

if you use 'ordinary application'
- imagefield  type ValueStorage

MyPicture = New Picture("C:\temp\image1.jpg");
imagefield  = New ValueStorage(MyPicture);

Controls.Picture.Picture = imagefield.Get();

Hello, Erdogan!

We recommend using the managed application mode.

Please, see following topics:
How to change the picture on a button programmatically?
How to insert a picture into the template?
How to add picture to spreadsheet programmatically

Hope, this helps.