c# - DataGridView System.InvalidOperationException Cell is not in a DataGridView

For the first time in a while, I can find no use information on this exception on Google... hoping someone else may have come across it.

I have a DataGridView that I validate for empty cells on the Leave event and remove those rows.

If I leave the last cell empty in the last row and tab away from the DGV the following exception is thrown:

System.InvalidOperationException: Cell is not in a DataGridView. The
cell cannot retrieve the inherited cell style.

I am not using Data Binding and a if I place a Breakpoint at this.dataGridView1.Rows.RemoveAt(c.RowIndex); It is hit and if if I step into this line the exception is thrown during the execution of non-user code...

I had thought this was to do with Uncommitted Changed but it seems explicitly committing the changes does not affect the outcome.

My Leave Event code:

    private void dataGridView1_Leave(object sender, EventArgs e)
    {

        if (this.dataGridView1.IsCurrentRowDirty || this.dataGridView1.IsCurrentCellDirty) this.dataGridView1.CommitEdit(DataGridViewDataErrorContexts.Commit);


        //Validate for empty rows
        foreach(DataGridViewRow row in this.dataGridView1.Rows)
        {

            foreach(DataGridViewCell c in row.Cells)
            {

                if(c.Value == null || c.Value.ToString() == String.Empty)
                {
                    if (c.EditedFormattedValue == null || c.EditedFormattedValue.ToString() == "")

                    {
                        this.dataGridView1.Rows.RemoveAt(c.RowIndex);
                        break;
                    }

                }
            }


        }

    }

Exception Data is here:

System.InvalidOperationException: Cell is not in a DataGridView. The cell cannot retrieve the inherited cell style.
   at System.Windows.Forms.DataGridViewCell.GetInheritedStyle(DataGridViewCellStyle inheritedCellStyle, Int32 rowIndex, Boolean includeColors)
   at System.Windows.Forms.DataGridView.OnCellValidating(DataGridViewCell& dataGridViewCell, Int32 columnIndex, Int32 rowIndex, DataGridViewDataErrorContexts context)
   at System.Windows.Forms.DataGridView.CommitEdit(DataGridViewCell& dataGridViewCurrentCell, DataGridViewDataErrorContexts context, DataGridViewValidateCellInternal validateCell, Boolean fireCellLeave, Boolean fireCellEnter, Boolean fireRowLeave, Boolean fireRowEnter, Boolean fireLeave)
   at System.Windows.Forms.DataGridView.EndEdit(DataGridViewDataErrorContexts context, DataGridViewValidateCellInternal validateCell, Boolean fireCellLeave, Boolean fireCellEnter, Boolean fireRowLeave, Boolean fireRowEnter, Boolean fireLeave, Boolean keepFocus, Boolean resetCurrentCell, Boolean resetAnchorCell)

   at System.Windows.Forms.DataGridView.ProcessDialogKey(Keys keyData)
   at System.Windows.Forms.Control.ProcessDialogKey(Keys keyData)
   at System.Windows.Forms.TextBoxBase.ProcessDialogKey(Keys keyData)
   at System.Windows.Forms.Control.PreProcessMessage(Message& msg)
   at System.Windows.Forms.Control.PreProcessControlMessageInternal(Control target, Message& msg)
   at System.Windows.Forms.Application.ThreadContext.PreTranslateMessage(MSG& msg)
   at System.Windows.Forms.Application.ThreadContext.System.Windows.Forms.UnsafeNativeMethods.IMsoComponent.FPreTranslateMessage(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(IntPtr dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)

   at System.Windows.Forms.Application.Run(Form mainForm)

Answer

If you're using foreach-loop, you can't remove items from the collection it's using. Here you're removing items from this.dataGridView1.Rows.

Try this:

for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
   DataGridViewRow row = dataGridView1.Rows[i];


   for (int k = 0; k < row.Cells.Count; k++)
   {
      DataGridViewCell c = row.Cells[k];

      if (c.Value == null || c.Value.ToString() == String.Empty)
      {
         if (c.EditedFormattedValue == null || c.EditedFormattedValue.ToString() == "")
         {
            this.dataGridView1.Rows.RemoveAt(c.RowIndex);


            // Decrease i, as the collection got smaller
            i--;
            break;
          }

       }
    }
 }