如何在Objective-C中更改标签栏的背景图像？

Question

I am develop in objective-C. I want to change the tab bar background like the following picture:

And the code is like the following:

UIImage *tabBarBackground = [UIImage imageNamed:@"tabbaritem_background.png"];
[[UITabBar appearance] setBackgroundImage:tabBarBackground];

But after setting the background image , the background is not at the correct place like the following:

The background image should be place at the bottom like the background in above picture.

Did I missing something ? Can someone help me ?

Thanks in advance.

Answer 1

I think is somewhere you go wrong, check if is this steps:

1. In the storyboard change the ViewController's background color for test.

2. Embed the ViewController in Tab Bar Controller

3. In the ViewController.m you can set the tabbar bacground color:

    - (void)viewDidLoad { [super viewDidLoad]; // Do any additional setup after loading the view, typically from a nib. [[UITabBar appearance] setBackgroundColor:[UIColor grayColor]]; // Here you can set the converted color form image, make sure the imageSize fit. } 

4. The result is below:

Answer 2

我认为可以尝试的方法- (UIImage *)resizableImageWithCapInsets:(UIEdgeInsets)capInsets resizingMode:(UIImageResizingMode)resizingMode ，因为您的backgroudimage的大小不等于tabbar'size。

Answer 3

Try this method to change your image to a ScaleImage.

+(UIImage *)getScaleImageNamed:(NSString *)name{
    UIImage *nomalImage = [UIImage imageNamed:name];

    CGFloat hInset = floorf(nomalImage.size.width / 2);
    CGFloat vInset = floorf(nomalImage.size.height / 2);

    UIImage *res = [nomalImage resizableImageWithCapInsets:UIEdgeInsetsMake(vInset, hInset, vInset, hInset)];

    return res;
}

Answer 4

Steps you may miss, hope that can help.

1. Make sure you have imported the background image (eg in Assets.xcassets )
2. Use resizableImageWithCapInsets: to resize the background image

3. Put the UIAppearance settings in AppDelegate.m :

    [[UITabBar appearance] setBackgroundImage:[[UIImage imageNamed:@"tabbaritem_background.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 0, 0, 0)]];