Question

我有一个带有图像的UI按钮的自定义视图的UIBarButtonItem，我想为不同的方向设置不同的UIImage，所以这是我的代码：

 UIButton * backButton = (UIButton *) ((UIBarButtonItem *) self.navBar_.topItem.leftBarButtonItem).customView;
        if (UIInterfaceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation]) && IS_IPAD) {        
            [backButton setBackgroundImage:[UIImage imageNamed:@"back-landscape.png"] forState:UIControlStateNormal];  
            [backButton setFrame: CGRectMake(0, 0, 46, 35)]; 
        } else {
            [backButton setBackgroundImage:[UIImage imageNamed:@"back-reading.png"] forState:UIControlStateNormal];  
            [backButton setFrame: CGRectMake(0, 0, 23, 19)]; 
        }

但是这不会改变UIButton图像，为什么会这样？

Answer 1

试试这个： -

UIButton * backButton ;
if (UIInterfaceOrientationIsLandscape([[UIApplication sharedApplication] statusBarOrientation]) && IS_IPAD) 
{ 
    backButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 66.0f, 36.0f)];       
    [backButton setImage:[UIImage imageNamed:@"back-landscape.png"] forState:UIControlStateNormal];  

} 
else 
{
    backButton = [[UIButton alloc] initWithFrame:CGRectMake(0.0f, 0.0f, 23, 19)];     
    [backButton setImage:[UIImage imageNamed:@"back-reading.png"] forState:UIControlStateNormal];  
    [backButton setFrame: CGRectMake(0, 0, 23, 19)]; 
}

[backButton addTarget:self action:@selector(goToHome) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem *HomeButton = [[UIBarButtonItem alloc] initWithCustomView: backButton];
[self.navigationItem setLeftBarButtonItem:HomeButton];

Answer 2

您应该通知您说它是 UIBarButtonItem ，但您在代码中使用 UIButton。

从ios5.0开始，您可以使用UIAppearence Protocol更改 UIBarButtonItem 背景图片，例如：


[[UIBarButtonItem appearance] setBackgroundImage: forState: barMetrics:]

您也可以使用elppa的方法，但请注意，您可以直接使用UIImageView作为customView参数。

Answer 3

您可以使用带有+ appereance方法的新代理类检查DOC，但仅适用于iOS5。对于早期支持，您可以在视图旋转视图控制器方法-willRotateToInterfaceOrientation时更新图像。侨

Answer 4

使用自定义UIButton创建UIBarButton：

_optionsButton = [UIButton buttonWithType:UIButtonTypeCustom];
[_optionsButton setImage:[UIImage imageNamed:@"menu2.png"] forState:UIControlStateNormal];
[_optionsButton addTarget:self action:@selector(optionsButtonPressed) forControlEvents:UIControlEventTouchUpInside];

UIBarButtonItem * optionsItem = [[UIBarButtonItem alloc] initWithCustomView:_optionsButton];

然后像往常一样为UIButton设置背景图像（而不是尝试更改UIBarButton的图像）。

[_optionsButton setImage:[UIImage imageNamed:@"keyboard.png"] forState:UIControlStateNormal];

这对我很有用

注意：当我经历这个时，我正在改变图片，具体取决于当前的图片。我发现我必须使用：

if ([[_optionsButton imageForState:UIControlStateNormal] isEqual:[UIImage imageNamed: @"keyboard.png"]]) {
    // Code for the certain button function 
}

让它发挥作用

更改UIBarButtonItem UIButton的图像

4 个答案: