I build my project in Xcode 8. UIPickerView separator lines are not visible in iOS 10 simulator and the devices, but works fine on iOS 9.3 devices and simulator. I tried to adju
UIPickerView *pickerView = [[UIPickerView alloc] initWithFrame:CGRectMake(0, 44, 320, 200)];
pickerView.backgroundColor = [UIColor whiteColor];
pickerView.dataSource = self;
pickerView.delegate = self;
[pickerView selectRow:0 inComponent:0 animated:YES];
[self.view addSubview:pickerView];
add the code [pickerView selectRow:0 inComponent:0 animated:YES];
before pickerView added to superView.