Argument exception occurring on form.ShowDialog() when I change the sortorder of the form's data grid

Ok, I'm utterly confused by this situation, so bear with me.

In my application, if you click on a button I have an editor form open

dgEditor = new fmDataGridFieldEditor();
dgEditor.ShowDialog();

This works fine, and my form shows up and operates correctly. The form has a data grid in it with some specified fields. Now, if I then change data in one of the columns of the datagrid (a column that is just meant for numbers) and then change the sorting order by clicking on the column header, my form crashes. with an ArgumentException error that says "Object must be of type Int32" on the dgEditor.ShowDialog(); line.

I don't understand what is going on or even how to start debugging this. This doesn't happen when I modify existing rows, or if the rows I enter are already sorted (e.g. 0,1,2 is fine but 0,1, 0 causes the crash).

Furthermore, I have visual studio 2010 setup to break on all exceptions, not just unhandled ones, but I'm getting an exception in the same place.

Finally, I tied the data grid's ColumnSortModeChanged event to show a message box, but even when the sorts don't crash the form, the message box doesn'开发者_运维知识库t show.

I'm at a loss on how to proceed with this.

The debugger shows the last line of code that you wrote. Which is the ShowDialog() call. If you look at Debug + Windows + Call stack then you see the methods in the .NET framework that are involved. Scroll the window up if necessary to see them all. DataGridView has a lot of built-in functionality, the source code isn't readily available although you can get it from the Reference Source. Not that this will help much, there's rather a lot of it.

Clearly there's some invalid data in one or more rows. Looks like a leading space, only guessing here without sitting in front of your machine. Implement the CellValidating event so the user cannot enter an improperly formatted number.

I just had this happen to me in VB. What I discovered was that when I copied the values from a textbox into the grid I didn't do a cast to int. Being VB I assumed it would cast implicitly, but the cell value is, I guess, an object, so it happily took a string. Everything looked right and worked right, until I happened to sort on that column. Maybe this will help someone else.

ShowDialog will throw an error if you are trying to create a PictureBox dynamically on the TableLayoutPanel. It does not allow two PictureBox elements to add a similar index on the Table or you could have a error if your are using MemorySTream and not closing it properly.