iOS开发之-Combined View Controller Interfaces

Combined View Controller Interfaces

Adding a Navigation Controller to a Tab Bar Interface

1. When embedding navigation controllers in a tab bar interface, you should embed only generic UINavigationController objects and not the system view controllers that are based on the UINavigationController class. Although the system provides custom navigation controllers for selecting contacts, picking images, and implementing other behaviors, these view controllers were designed to be presented modally in nearly all cases.

Creating the Objects in Interface Builder

Creating the Objects Programmatically

- (void)applicationDidFinishLaunching:(UIApplication *)application {
   self.tabBarController = [[[UITabBarController alloc] init] autorelease];
 
   MyViewController1* vc1 = [[[MyViewController1 alloc] init] autorelease];
   MyViewController2* vc2 = [[[MyViewController2 alloc] init] autorelease];
   MyViewController3* vc3 = [[[MyViewController3 alloc] init] autorelease];
   MyNavRootViewController* vc4 = [[[MyNavRootViewController alloc] init] autorelease];
   UINavigationController* navController = [[[UINavigationController alloc]
                           initWithRootViewController:vc4] autorelease];
 
   NSArray* controllers = [NSArray arrayWithObjects:vc1, vc2, vc3, navController, nil];
   tabBarController.viewControllers = controllers;
 
   // Add the tab bar controller's current view as a subview of the window
   window = [[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]] autorelease];
   [window addSubview:tabBarController.view];
}

Displaying a Navigation Controller Modally

1. You must always configure the view controller appropriately before presenting it. 

MyViewController1*  rootVC = [[MyViewController1 alloc] init];
MyViewController2*  nextVC = [[MyViewController2 alloc] init];
 
// Create the nav controller and add the view controllers.
UINavigationController*  theNavController = [[UINavigationController alloc]
                          initWithRootViewController:rootVC];
[theNavController pushViewController:nextVC animated:NO];
 
// Display the nav controller modally.
[currentViewController presentModalViewController:theNavController animated:YES];
 
// Release the view controllers to prevent over-retention.
[rootVC release];
[nextVC release];
[theNavController release];

Displaying a Tab Bar Controller Modally

1. It is possible (albeit uncommon) to present a tab bar controller modally in your application.

2. The tab bar controller must already be configured before you present it. 

Using Table View Controllers in a Navigation Interface

// Implement something like this in your UITableViewController subclass
// or in the delegate object you use to manage your table.
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
   // Create a view controller with the title as its
   // navigation title and push it.
   NSUInteger row = indexPath.row;
   if (row != NSNotFound)
   {
      // Create the view controller and initialize it with the
      // next level of data.
      MyViewController *viewController = [[MyViewController alloc]
                   initWithTable:tableView andDataAtIndexPath:indexPath];
      [[self navigationController] pushViewController:viewController
                   animated:YES];
   }
}