如何从主视图加载子视图？

Question

I am very new to Obj-C and learning iphone development. My question is how to add subview from app delegate. Lets say I added subview called "MainView" from "applicationDidFinishLaunching" method.

- (void)applicationDidFinishLaunching:(UIApplication *)application {    

MainViewController *aViewController = [[MainViewController alloc] initWithNibName:@"MainView" bundle:nil];
self.mainViewController = aViewController;
[aViewController release];

[window addSubview:mainViewController.view];
// Override point for customization after application launch
[window makeKeyAndVisible];

}

"MainView.xib" file has a button to show its child view. When the button is clicked, it calls "showChildView" method.

- (IBAction)showChildView:(id)sender {
    if (self.childViewController == nil) {
        ChildViewController *childController = [[ChildViewController alloc] initWithNibName:@"ChildView" bundle:nil];
        self.childViewController = childController;
        [childController release];
    }

    [self.view insertSubview:childViewController.view atIndex:0];
}

From this code, when app launches, it shows "MainView" with a button. But when I clicked the button, the button is still visible as well as the content from the "ChildView.xib" file too.

How can I hide the "MainView" when I pressed the button and show only the contents of the "ChildView"?

Thanks for your help in advance.

Answer 1

well, you have to remove the original view first, before inserting the new subview, do it this way

- (IBAction)showChildView:(id)sender {
    if (self.childViewController == nil) {
        ChildViewController *childController = [[ChildViewController alloc] initWithNibName:@"ChildView" bundle:nil];
        self.childViewController             = childController;
        [childController release];
    }
    [self.mainViewControlle.view removeFromSuperView];
    [self.view insertSubview:childViewController.view atIndex:0];
}

Hope this helps.

Answer 2

您可能想要查看Utility Utility示例-该示例演示了如何在两个带有动画的视图之间切换以及从父视图添加/删除视图。

Answer 3

you might want to create a navigation controller in the main view and than push the childviewcontroller onto it when invoking showChildView. You'll get the back navigation button for free that way