GAMS MATLAB API WORKINGDIRECTORY

Hi guys, I need some help.
I am studying the code in apifiles\Matlab\examples\transport_gdx.m, and I want to change the working directory from the default temp file to a new one.
Here’s my code:
function transport_gdx()

wsInfo = GAMS.GAMSWorkspaceInfo('','E:\Database\Papers\GraduationDesignThesis\Codes\SCUCSpeedUp\Drafts','off');
ws = GAMS.GAMSWorkspace(wsInfo);  GAMSWorkspace

…(The following codes are same with the transport_gdx.m)
There are no error reports but file data.gdx do not show up at the expected place. What can I do? I am appreciated for your help!