Hello All (at 2.30 in the morning)

You see what being polite does for you? Visual C#, recognising my recent compliment, has at last given me the right form for the code line I was looking for --- which is :

testcell = (int)this.sF3DataSet.Tables["SF3"].Rows[200]["Close"];

--- and has now compiled without error !

So there you go, eh?

Now all I have to do is index the record, or sixteen of them actually, instead of just setting '200' as a constant (remembering that the index starts at 0 and not 1, yeah?) and then transfer their fields into a local array of structures (don't let me even get started on that as a mental-driving topic) instead of into a single integer, and Bob's your uncle, eh?

Right. Right. Okay. Bit of a sleep first, though, I think . . .


Cheers and regards to all,

;) Martin Woodhouse

Martin,

Glad you got it worked out. I checked out your site, very interesting stuff. I like the idea of the Lightbook.

-Peter
peterlanoie.blog

I got here too late to be of help, but the cause of this problem is probably because of the difference between value types and reference types. Always remember: with reference types like a data grid, all you get is a memory address that points to where the data will be stored. That is, when you drag a data grid onto a form, in essence you are saying:

DataGridView myGrid;

This creates nothing but a 4-byte variable capable of holding a memory address that will ultimately point to the data in the grid. The current value of myGrid is null after the statement above. Your statement:

int testcell = SF3priceGrid.Rows(10).Cells(4).Value;

failed is because you are trying to make "Rows" a method call. As soon as Visual Studio saw the opening parenthesis after "Rows", it gave up because it couldn't find an object named SF3priceGrid with a method named Rows(). However, even if you had used brackets, as in:

int testcell = SF3priceGrid.Rows[10].Cells[4].Value;

that would still have failed because there are no row objects yet. The reason you got it to work is because you used data binding to actually create a data grid object in memory. Data binding has the effect of sending a memory allocation message to the Windows Memory Manager and creates a free memory block for the upcoming data. The memory address for this block is what gets assigned into myGrid, or SF3priceGrid in your example.

Dr. Purdum


Jack Purdum, Ph.D.
Author: Beginning C# 3.0: Introduction to Object Oriented Programming (and 14 other programming texts)