在4.0裡定義導航條按鈕通常是生成普通按鈕，再用它生成導航條專用按鈕。

1. UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];  
2. [button setBackgroundImage:[UIImage imageNamed:@"button_main.png"]  
3.                                       forState:UIControlStateNormal];  
4. [button addTarget:self action:@selector
   (GotoSettings)  
5.              forControlEvents:UIControlEventTouchUpInside];  
6. button.frame = CGRectMake(x, y, x1, x2);  
7. UIBarButtonItem *menuButton = [[UIBarButtonItem alloc] initWithCustomView:menu];  
8. self.navigationItem.rightBarButtonItem = menuButton;  
9. [button release];  
10. [menuButton release];  

1. UISegmentedControl *SegmentedControl = [[UISegmentedControl alloc] initWithItems:  
2.                                          [NSArray arrayWithObjects:  
3.                                           @"開始",  
4.                                           @"暫停"
   , nil]];  
5. [SegmentedControl addTarget:self action:@selector(segmentAction:)   
6.             forControlEvents:UIControlEventValueChanged];  
7. SegmentedControl.frame = CGRectMake(0, 0, 80, 30);  
8. SegmentedControl.segmentedControlStyle = UISegmentedControlStyleBar;  
9. SegmentedControl.momentary = YES;  
10. SegmentedControl.tintColor = [UIColor colorWithHue:0.6 saturation:0.33 brightness:0.69 alpha:0];  
11. //defaultTintColor = [segmentedControl.tintColor retain];    // keep track of this for later
12. UIBarButtonItem *segmentBarItem = [[UIBarButtonItem alloc]   
13.                                        initWithCustomView:SegmentedControl];  
14. self.navigationItem.rightBarButtonItem = segmentBarItem;  

1. - (void)segmentAction:(id)sender  
2. {  
3.     //NSLog(@"segmentAction: selected segment = %d", [sender selectedSegmentIndex]);
4.     if ([sender selectedSegmentIndex] == 0) {  
5.         //[self startAll];
6.     }elseif ([sender selectedSegmentIndex] == 1) {  
7.         //[self stopAll];
8.     }  
9. }  

1. UIBarButtonItem *startBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemPlay target:self action:@selector(startDownloadAll)];  
2. UIBarButtonItem *pauseBtn = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemPause target:self action:@selector(stopDownloadAll)];  
3. [self.navigationItem setRightBarButtonItems:[NSArray arrayWithObjects: pauseBtn,startBtn,nil]];