https://learn.microsoft.com/ja-jp/dotnet/api/system.windows.forms.datagridview.cellvaluechanged?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
DataGridView.CellValueChanged Event (System.Windows.Forms) | Microsoft Learn
Occurs when the value of a cell changes.
event systemwindows formsdatagridviewmicrosoftlearn