https://learn.microsoft.com/ja-jp/dotnet/api/system.windows.data.binding.updatesourcetrigger?view=netframework-4.8.1&viewFallbackFrom=windowsdesktop-10.0
Binding.UpdateSourceTrigger Property (System.Windows.Data) | Microsoft Learn
Gets or sets a value that determines the timing of binding source updates.
property systembindingwindowsdatamicrosoft