Objective-C中侧边菜单：主视图与侧视图向左滑动返回的实现方法

Hey there! Let's get that side menu close animation sorted out. You've already nailed the open flow, so let's build on that with a clean, smooth close transition.

First, a quick tweak to your open code to make it more robust (and easier to hook up the close logic):

• Let's use a property to keep a reference to your side view controller instead of a local variable (this avoids messy direct instance variable access like self->sample and lets us access it later for closing)
• Fix the side view's initial position so it slides in properly — right now it's just appearing instantly instead of sliding from the left

Here's the updated open action:

// First, add this property to your view controller's header or class extension
@property (nonatomic, strong) UIViewController *sideViewController;

- (IBAction)showSideView:(id)sender {
    NSLog(@"sideview button pushed");
    
    // Animate main view to the right
    [UIView animateWithDuration:0.5f animations:^{
        self.view.frame = CGRectOffset(self.view.frame, 243, 0);
        // Add shadow effect
        self.view.layer.shadowColor = [UIColor whiteColor].CGColor;
        self.view.layer.shadowOpacity = 0.8;
        self.view.layer.shadowRadius = 3.0;
        self.view.layer.shadowOffset = CGSizeMake(-2.0, -2.0);
    }];
    
    // Initialize side view controller
    self.sideViewController = [self.storyboard instantiateViewControllerWithIdentifier:@"side"];
    // Start side view off-screen to the left
    CGRect sideViewFrame = self.view.bounds;
    sideViewFrame.origin.x = -sideViewFrame.size.width;
    self.sideViewController.view.frame = sideViewFrame;
    
    [self.view.window addSubview:self.sideViewController.view];
    
    // Animate side view sliding in from the left
    [UIView animateWithDuration:0.5f animations:^{
        self.sideViewController.view.frame = self.view.bounds;
    }];
}

Now, let's add the close action. This will animate the main view back to its original position, slide the side view off-screen to the left, then clean up the subview and shadow:

- (IBAction)hideSideView:(id)sender {
    NSLog(@"close sideview button pushed");
    
    // Get the original frame of the main view (before sliding right)
    CGRect originalMainFrame = CGRectOffset(self.view.frame, -243, 0);
    
    // Animate main view back to original position, and side view off-screen
    [UIView animateWithDuration:0.5f animations:^{
        self.view.frame = originalMainFrame;
        // Remove shadow effect smoothly
        self.view.layer.shadowOpacity = 0.0;
        
        // Slide side view back to the left off-screen
        CGRect sideViewFrame = self.sideViewController.view.frame;
        sideViewFrame.origin.x = -sideViewFrame.size.width;
        self.sideViewController.view.frame = sideViewFrame;
    } completion:^(BOOL finished) {
        // After animation completes, remove the side view from window to free up memory
        [self.sideViewController.view removeFromSuperview];
        self.sideViewController = nil;
    }];
}

Key Notes: #

• Using a property for the side view controller lets us easily reference it when we need to close it
• The completion block in the close animation ensures we only remove the side view after the animation finishes, which looks much cleaner
• We're animating the shadow opacity back to 0 instead of just removing the shadow properties, which gives a smoother transition
• The side view starts off-screen on open, so its slide-in animation is consistent with the slide-out on close

You can hook up the hideSideView: action to a button in your side view, or even add a tap gesture recognizer to the main view to trigger closing when the user taps outside the side menu.

内容的提问来源于stack exchange，提问作者stefanosn