Apple review require my app to remember the folder that user selected last time. But I can not make it under Sandbox. the -setDirectoryURL seems not working under Sandbox. What should I do? Thank you for your help!
// read string saveFolder from NSUserDefaults
NSOpenPanel * myPanel = [NSOpenPanel openPanel];
[myPanel setTitle:@"Select Output Folder"];
[myPanel setCanChooseDirectories:YES];
[myPanel setCanCreateDirectories:YES];
[myPanel setAllowsMultipleSelection:NO];
[myPanel setCanChooseFiles:NO];
NSLog(@"before openpanel:folder=%@",saveFolder); // <== return normal
[myPanel setDirectoryURL:[NSURL URLWithString:saveFolder.stringValue]];
NSLog(@"readback:folder=%@",[[myPanel URL] path]); // <== return nil here
if ([myPanel runModal] == NSOKButton)
{
//
saveFolder = [[myPanel URL] path]];
// then save the saveFolder string to NSUserDefaults
//
}