A modal window is shown when changing the value of the DatePicker. Because of that the value of the DatePicker could not be changed.


import java.time.LocalDate;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.DatePicker;
import javafx.scene.layout.VBox;
import javafx.stage.FileChooser;
import javafx.stage.Stage;

public class Test extends Application {

@Override
public void start(Stage stage) throws Exception {
DatePicker datePicker = new DatePicker(LocalDate.now());
stage.setScene(new Scene(new VBox(datePicker), 300, 200));
stage.show();

datePicker.setOnAction(e -> {
if (stage.isShowing()) {
new FileChooser().showOpenDialog(stage);
}
});
}

public static void main(String[] args) {
launch(args);
}

}