设置UINavigationBar的leftBarButtonItem和rightBarButtonItem

navBar = [[UINavigationBar alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, 40)];
[self.view addSubview:navBar];
navBar.barStyle = UIBarStyleDefault;
[navBar release];

UIBarButtonItem* cancelBtnItem = [[UIBarButtonItem alloc] initWithTitle:@"取消" style:UIBarButtonItemStylePlain
target:self action:@selector(cancelBtnPress)];
UIBarButtonItem* sureBtnItem = [[UIBarButtonItem alloc] initWithTitle:@"确定" style:UIBarButtonItemStyleDone
target:self action:@selector(sureBtnPress)];
UINavigationItem* navItem = [[UINavigationItem alloc] initWithTitle:@"设置经度"];
navItem.leftBarButtonItem = cancelBtnItem;
navItem.rightBarButtonItem = sureBtnItem;
navItem.hidesBackButton = YES;
[cancelBtnItem release];
[sureBtnItem release];

navigationController.navigationBar.tintColor = [UIColor colorWithRed:(21.0/255.0) green:(153.0 / 255.0) blue:(224.0 / 255.0) alpha:1];

[navBar pushNavigationItem:navItem animated:NO];
[navItem release];