iphone 2按鈕導航欄

Question

我有一個導航欄（導航），我已經包括2個按鈕導航欄，但如果我分配一個按鈕左，我的導航按鈕消失（doughh）， 所以我怎麼能，我的導航按鈕，還有2個按鈕？ 這裏的代碼我使用：

從viewDidLoad中

UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
infoButton.frame = CGRectMake(0, 10, 40, 30); 
UIImage *img = [UIImage imageNamed:@"eye.png"]; 
[infoButton setImage:img forState:UIControlStateNormal]; [img release]; 
//[infoButton setTitle:@"xuxu"forState:UIControlStateNormal]; 
[infoButton addTarget:self action:@selector(infoButtonAction) forControlEvents:UIControlEventTouchUpInside]; 
UIBarButtonItem *modalButton = [[UIBarButtonItem alloc] initWithCustomView:infoButton]; 
[self.navigationItem setRightBarButtonItem:modalButton animated:YES]; 
[modalButton release]; 


UIButton* iButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
iButton.frame = CGRectMake(0, 10, 40, 30); 
UIImage *imag = [UIImage imageNamed:@"eye.png"]; 
[iButton setImage:imag forState:UIControlStateNormal]; [imag release]; 
//[infoButton setTitle:@"xuxu"forState:UIControlStateNormal]; 
[infoButton addTarget:self action:@selector(infoButtonAction) forControlEvents:UIControlEventTouchUpInside]; 
UIBarButtonItem *modalButton2 = [[UIBarButtonItem alloc] initWithCustomView:iButton]; 
[self.navigationItem setLeftBarButtonItem:modalButton2 animated:YES]; 
[modalButton2 release]; 

所以我的第二個按鈕被設置爲

setLeftBarButtonItem

有像setCenter什麼？或者用x，y設置位置的方法？ 我需要2個按鈕保留我的按鈕左側用於導航目的（3個按鈕）

謝謝！

Answer 1

使用此代碼對理解你怎麼能導航欄

UIButton* infoButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    infoButton.frame = CGRectMake(0, 10, 40, 30); 
    UIImage *img = [UIImage imageNamed:@"eye.png"]; 
    [infoButton setImage:img forState:UIControlStateNormal]; [img release]; 
    [infoButton setTitle:@"xuxu"forState:UIControlStateNormal]; 
    [infoButton addTarget:self action:@selector(infoButtonAction) forControlEvents:UIControlEventTouchUpInside]; 
    UIBarButtonItem *modalButton = [[UIBarButtonItem alloc] initWithCustomView:infoButton]; 
    [self.navigationItem setRightBarButtonItem:modalButton animated:YES]; 
    [modalButton release]; 


    UIButton* iButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    UIButton* aButton = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    aButton.frame = CGRectMake(0, 10, 40, 30); 
    iButton.frame = CGRectMake(42, 10, 40, 30); 
    UIImage *imag = [UIImage imageNamed:@"eye.png"]; 
    [iButton setImage:imag forState:UIControlStateNormal]; 
    [aButton setImage:imag forState:UIControlStateNormal]; 
    [imag release]; 
    [infoButton setTitle:@"xuxu"forState:UIControlStateNormal]; 


    [iButton addTarget:self action:@selector(infoButtonAction) forControlEvents:UIControlEventTouchUpInside]; 
    [aButton addTarget:self action:@selector(infoButtonAction) forControlEvents:UIControlEventTouchUpInside]; 
    UIView *viewForAdd=[[UIView alloc] initWithFrame:CGRectMake(0,0,100,50)]; 
    [viewForAdd addSubview:iButton]; 
    [viewForAdd addSubview:aButton]; 
    UIBarButtonItem *modalButton2 = [[UIBarButtonItem alloc] initWithCustomView:viewForAdd]; 
    [self.navigationItem setLeftBarButtonItem:modalButton2 animated:YES]; 
    [modalButton2 release];