iOS 在TabViewController中設定Tab Bar，且實現自訂

標籤：style   blog   http   io   color   ar   os   使用   sp   

開發環境：Xcode 6.1 iOS 7.1.2 & iOS 8.1

實現功能一，在開啟APP時即顯示第三個Tab對應的View；

實現功能二，給每一個Tab設定圖片和選中圖片。

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    // Override point for customization after application launch.        //---------------------------------------------    // set the first view as camera view and custom tab bar    //---------------------------------------------    [self setTabBar];｝

實現setTab Bar：

//---------------------------------------------#pragma mark - Tab Bar//---------------------------------------------- (void) setTabBar{    UITabBarController *tabViewController = (UITabBarController *) self.window.rootViewController;    [tabViewController setSelectedIndex:2];    UITabBar *tabBar = tabViewController.tabBar;    [tabBar setTintColor: [UIColor greenColor]];        // First    UITabBarItem *tabBarItem1 = [tabBar.items objectAtIndex:0];    UIImage* tabBarItem1Image = [UIImage imageNamed:@"XXX"];    UIImage *scaledTabBarItem1Image = [UIImage imageWithCGImage:[tabBarItem1Image CGImage] scale:(tabBarItem1Image.scale * 3) orientation:(tabBarItem1Image.imageOrientation)];    UIImage* tabBarItem1SelectedImage = [UIImage imageNamed:@"XXX"];    UIImage *scaledTabBarItem1SelectedImage = [UIImage imageWithCGImage:[tabBarItem1SelectedImage CGImage] scale:(tabBarItem1SelectedImage.scale * 3) orientation:(tabBarItem1SelectedImage.imageOrientation)];    (void)[tabBarItem1 initWithTitle:@"First" image:scaledTabBarItem1Image selectedImage:scaledTabBarItem1SelectedImage];        // Second    UITabBarItem *tabBarItem2 = [tabBar.items objectAtIndex:1];    UIImage* tabBarItem2Image = [UIImage imageNamed:@"XXX"];    UIImage *scaledTabBarItem2Image = [UIImage imageWithCGImage:[tabBarItem2Image CGImage] scale:(tabBarItem2Image.scale * 3) orientation:(tabBarItem2Image.imageOrientation)];    UIImage* tabBarItem2SelectedImage = [UIImage imageNamed:@"XXX"];    UIImage *scaledTabBarItem2SelectedImage = [UIImage imageWithCGImage:[tabBarItem2SelectedImage CGImage] scale:(tabBarItem2SelectedImage.scale * 3) orientation:(tabBarItem2SelectedImage.imageOrientation)];    (void)[tabBarItem2 initWithTitle:@"Second" image:scaledTabBarItem2Image selectedImage:scaledTabBarItem2SelectedImage];        // And Others Tabs － 同樣的方法    }

在didFinishLaunchingWithOptions就自訂跳轉直接到某一個Tab：

    UITabBarController *tabViewController = (UITabBarController *) self.window.rootViewController;    [tabViewController setSelectedIndex:2];

為了保證像素，使表徵圖比較清晰，使用了大的圖片，然後用代碼將其縮小：

[UIImage imageWithCGImage:[tabBarItem1Image CGImage] scale:(tabBarItem1Image.scale * 3) orientation:(tabBarItem1Image.imageOrientation)];

另：

因為selected image系統總是會將圖片設定成和tint color一樣顏色的圖片，預設是藍色，所以需要自己設定你需要的顏色：

[tabBar setTintColor: [UIColor greenColor]];

參考連結：

http://stackoverflow.com/questions/18894985/uitabbar-not-showing-selected-item-images-in-ios-7

http://stackoverflow.com/a/19386156/3458781

http://www.appcoda.com/ios-programming-how-to-customize-tab-bar-background-appearance/

iOS 在TabViewController中設定Tab Bar，且實現自訂