UIDatePicker 之显示中文 年月日

 picker_start=[[UIDatePicker alloc]initWithFrame:CGRectMake(centerView.frame.size.width/2-100,centerView.frame.size.height/2-50, 400, 80)];
        [picker_start setDatePickerMode:UIDatePickerModeDate];
        NSLocale * locale = [[NSLocale alloc] initWithLocaleIdentifier:@"Chinese"];
        [picker_start setLocale:locale];
        [bg_view addSubview:picker_start];