Cannot Set Value To FirstDisplayedScrollingRowIndex

Question

I am trying to stop the DataGridView from scrolling after ResetBindings is called.

I call ResetBindings after I update a value in the list that is bound to it.

After calling ResetBindings, I am unable to assign a value to FirstDisplayedScrollingRowIndex.

Please note that no exception is being thrown.

This is the code that I am using:

int currentRowIndex = dgvStuff.FirstDisplayedScrollingRowIndex;

dgvStuff.CellEnter -= dgvStuff_CellEnter;
dgvStuff.Scroll -= dgvStuff_Scroll;
bindingSource.ResetBindings(false); // FirstDisplayedScrollingRowIndex value gets modified after this call;
dgvStuff.Scroll += dgvStuff_Scroll;
dgvStuff.CellEnter += dgvStuff_CellEnter;

dgvStuff.FirstDisplayedScrollingRowIndex = currentRowIndex; // This value is not being set;

The above code is in the CellValidating event for the DataGridView.

Stepping through the above code:

• currentRowIndex has a value of 12 after the first line is executed
• ResetBindings is executed which causes FirstDisplayedScrollingRowIndex to hold the value of 3
• FirstDisplayedScrollingRowIndex is not being set to 12 after the last line is executed

I am not sure where the value 3 is coming from, but I know it is somehow being applied in the background after ResetBindings is called.

Can someone help me understand why I am unable to modify the value of FirstDisplayedScrollingRowIndex after calling ResetBindings?

https://learn.microsoft.com/en-us/dotnet/api/system.windows.forms.datagridview.firstdisplayedscrollingrowindex

Answer 1

All you need to do is change the CurrentCell in the DataGridView then you should be able to set the value to FirstDisplayedScrollingRowIndex.

I know that this is a weird fix but it works for me:

int rowIndex = dgvStuff.CurrentCell.RowIndex;
int columnIndex = dgvStuff.CurrentCell.ColumnIndex;
int currentRowIndex = dgvStuff.FirstDisplayedScrollingRowIndex;

dgvStuff.CellEnter -= dgvStuff_CellEnter;
dgvStuff.Scroll -= dgvStuff_Scroll;
bindingSource.ResetBindings(false);

if (dgvStuff.RowCount > 0)
{
    dgvStuff.CurrentCell = dgvLEDs[0, 0]; // This line alone fixes the issue;
    dgvStuff.CurrentCell = dgvLEDs[columnIndex, rowIndex]; // I added this line because I needed to specify the current cell;
}

dgvStuff.FirstDisplayedScrollingRowIndex = currentRowIndex; // This value is NOW being set;

dgvStuff.Scroll += dgvStuff_Scroll;
dgvStuff.CellEnter += dgvStuff_CellEnter;

I hope that this helps anyone that got stuck like me on this. Good luck.