Sometimes you want to display predecessors using a custom string format in the Predecessors column of GanttChartDataGrid component from Gantt Chart Light Library.
To transform values from the expected format to your custom display time format you can use a WPF converter class. An PredecessorFormatConverter example class is available with full C# source code that you can review. Feel free to copy and adapt the code as needed in your application.
This sample shows how you can convert dependency abbreviations from S to I and from F to E, and also how lag values can be displayed in working days instead of hours.