为什么导航栏的 UIBarButton 项目没有图像

Question

这是我的代码。这是添加图像，但图像出现在导航栏中。

UIToolbar* toolbartop = [[UIToolbar alloc]
                      initWithFrame:CGRectMake(0, 0, 100, 45)];
[toolbar setBarStyle: UIBarStyleBlackOpaque];

// create an array for the buttons
NSMutableArray* buttonstop = [[NSMutableArray alloc] initWithCapacity:5];


UIBarButtonItem *remainderButton = [[UIBarButtonItem alloc] 
                                    initWithImage:[UIImage imageNamed:@"home.png"]
                                    style:UIBarButtonItemStylePlain 
                                    target:self 
                                    action:@selector(LoadOption:)];


 [buttonstop addObject:remainderButton];
[remainderButton release];

UIBarButtonItem *faveButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"home.png"]
                                                               style:UIBarButtonItemStylePlain
                                                              target:self
                                                              action:@selector(homeAction)];
[buttonstop addObject:faveButton];
[faveButton release];


// put the buttons in the toolbar and release them
[toolbartop setItems:buttonstop animated:NO];
[buttonstop release];

// place the toolbar into the navigation bar
self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:toolbartop];

但此代码在导航右侧栏中显示图像。

UIBarButtonItem *settingButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"home.png"]
                                                               style:UIBarButtonItemStylePlain
                                                              target:self
                                                              action:@selector(homeAction)];
self.navigationItem.rightBarButtonItem = settingButton;

为什么左侧导航栏按钮不显示图像？

[toolbartop release];

Answer 1

您可以将图像添加到左侧 BarButtonItem，如下所示：

UIButton *button1 = [[UIButton alloc] init];
button1.frame=CGRectMake(0,0,105,30);
[button1 setBackgroundImage:[UIImage imageNamed: @"image1.png"] forState:UIControlStateNormal];
[button1 addTarget:appDelegate action:@selector(Open_Link1) forControlEvents:UIControlEventTouchUpInside];

UIButton *button2 = [[UIButton alloc] init];
button2.frame=CGRectMake(105,0,105,30);
[button2 setBackgroundImage:[UIImage imageNamed: @"image2.png"] forState:UIControlStateNormal];
[button2 addTarget:appDelegate action:@selector(Open_Link2) forControlEvents:UIControlEventTouchUpInside];

UIView *viewButtons = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 210, 30)];
[viewButtons addSubview:button1];
[viewButtons addSubview:button2];
[button1 release];
[button2 release];

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]initWithCustomView:viewButtons];
[viewButtons release];

这里请确保代码中必须存在方法“Open_Link1”和“Open_Link2”，如下所示：

-(void)Open_Link1
{
     // Write your logic
}

-(void)Open_Link2
{
     // Write your logic
}

如果您需要更多帮助，请告诉我。

Answer 2

框架自动使用左栏按钮项来显示“后退”按钮。您不能在此处放置任何内容，至少当您的导航栏由 UINavigationController 管理时不能。为此，您必须自己处理 UINavigationBar。

编辑：
在 leftBarButtonItem 中，尝试将 UISegmentedControl 而不是 UIToolbar 作为工具栏顶部。

Answer 3

您正在向工具栏添加按钮，但没有将工具栏添加到任何视图。尝试直接使用设置按钮

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:buttonStop];