iOS 使用系統的UITabBarController 修改展示的圖片大小

1. 設置TabBarItem圖片的大小

 1 - (void)configurationAppTabBarAndNavigationBar
{
    // 選中的item普通狀態圖片的大小
    UIImage *normalImage = self.navigationController.tabBarController.tabBar.selectedItem.image;
    UIImage *tabNormalImage = [ToolObject createNewImageWithColor:normalImage multiple:1.1];
    tabNormalImage = [tabNormalImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    [self.navigationController.tabBarController.tabBar.selectedItem setImage:tabNormalImage];
    // 選中的item選中撞他圖片的大小
    UIImage *selectImage = self.navigationController.tabBarController.tabBar.selectedItem.selectedImage;
    UIImage *tabSelectImage = [self createNewImageWithColor:selectImage multiple:1.1];
    tabSelectImage = [tabSelectImage imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
12　　　// 設置點擊圖片放大縮小的動畫
    [self.navigationController.tabBarController.tabBar.selectedItem setSelectedImage:tabSelectImage];
    self.navigationController.tabBarController.tabBar.tintColor = [UIColor colorWithRed:0.11f green:0.61f blue:0.97f alpha:1.00f];
    self.navigationController.tabBarController.tabBar.barTintColor = [UIColor colorWithRed:0.85f green:0.85f blue:0.85f alpha:1.00f];
}

2.圖片放大或壓縮處理 ，圖片放大倍數 0 ~ 2 之間 ，0~1 縮小圖片，1~2 放大圖片 

 1 /**
 *  根據image 返回放大或縮小之后的圖片
 *
 *  @param image    原始圖片
 *  @param multiple 放大倍數 0 ~ 2 之間
 *
 *  @return 新的image
 */
+ (UIImage *) createNewImageWithColor:(UIImage *)image multiple:(CGFloat)multiple
{
    CGFloat newMultiple = multiple;
    if (multiple == 0) {
        newMultiple = 1;
    }
    else if((fabs(multiple) > 0 && fabs(multiple) < 1) || (fabs(multiple)>1 && fabs(multiple)<2))
    {
        newMultiple = multiple;
    }
    else
    {
        newMultiple = 1;
    }
    CGFloat w = image.size.width*newMultiple;
    CGFloat h = image.size.height*newMultiple;
    CGFloat scale = [UIScreen mainScreen].scale;
    UIImage *tempImage = nil;
    CGRect imageFrame = CGRectMake(0, 0, w, h);
    UIGraphicsBeginImageContextWithOptions(image.size, NO, scale);
    [[UIBezierPath bezierPathWithRoundedRect:imageFrame cornerRadius:0] addClip];
    [image drawInRect:imageFrame];
    tempImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return tempImage;
}

這樣就可以修改選中狀態和普通狀態下的TabBarItem 圖片的大小 ，是不是很簡單呢，不足之處，還請大家多多指教