if I not check the header checkbox,the RecordSelectorStyle is arrow. It's ok,
But if i check the header checkbox ,the xamdatagrid is follow,,the RecordSelectorStyle is not arrow,all of the record has an icon,It's a bug??
No,
This is not a bug. This indicator says that the record has been updated, but the changes are not yet submitted. When you check/uncheck the checkbox, you are probably updating the underlying data source. If you do not want that to appear, you can call the Commit command, like this;
_xamDataGrid.ExecuteCommand(DataPresenterCommands.CommitChangesToAllRecords);