- (IBAction)backAction:(UIBarButtonItem *)sender {

UIAlertView *alertview = [[UIAlertView alloc] initWithTitle:@"提示" message:@"你确定放弃添加吗" delegate:self cancelButtonTitle:@"取消" otherButtonTitles:@"确定", nil];
[alertview show];

}
#pragma mark alertview

//UIAlertView协议中的方法
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
switch (buttonIndex) {
case 0:
break;
case 1:
[self dismissViewControllerAnimated:YES completion:nil];
break;
default:
break;
}
}