iOS: Modal ViewController with transparent background

问题

I\'m trying to present a view controller modally, with a transparent background. My goal is to let both the presenting and presented view controllers\'s view to be displayed at the same time. The problem is, when the presenting animation finishes, the presenting view controller\'s view disappears.

- (IBAction)pushModalViewControllerButtonPressed:(id)sender
{
    ModalViewController *modalVC = [[ModalViewController alloc] init];
    [self presentViewController:modalVC animated:YES completion:nil];
}

I know I could just add the view as a subview, but I\'d like to avoid this solution for some reason. How could I fix it?

回答1:

This following code only works on the iPad.

self.view.backgroundColor = [UIColor clearColor];
self.modalPresentationStyle = UIModalPresentationCurrentContext;
[self presentModalViewController:modalVC animated:YES];

I would go with adding a sub view.

Here is a very good discussion. Look at the comments specifically. Not only the answer.

Modal View

If I were you I wouldn't do it. I would add a sub view and do it. It seems to give me a better control over things.

EDIT:

As mentioned by Paul Linsay, since iOS 8 all that's needed is UIModalPresentationOverFullScreen for the modalPresentationStyle of the ViewController being presented. This would also cover of navigationBar and tabBar buttons.

回答2:

For those trying to get this to work in iOS 8, the "Apple-approved" way to display a transparent modal view controller is by setting modalPresentationStyle on the presented controller to UIModalPresentationOverCurrentContext.

This can be done in code, or by setting the properties of the segue in the storyboard.

From the UIViewController documentation:

UIModalPresentationOverCurrentContext

A presentation style where the content is displayed over only the parent view controller’s content. The views beneath the presented content are not removed from the view hierarchy when the presentation finishes. So if the presented view controller does not fill the screen with opaque content, the underlying content shows through.

When presenting a view controller in a popover, this presentation style is supported only if the transition style is UIModalTransitionStyleCoverVertical. Attempting to use a different transition style triggers an exception. However, you may use other transition styles (except the partial curl transition) if the parent view controller is not in a popover.

Available in iOS 8.0 and later.

https://developer.apple.com/documentation/uikit/uiviewcontroller

The 'View Controller Advancements in iOS 8' video from WWDC 2014 goes into this in some detail.

Note:

Be sure to give your presented view controller a clear background color, lest it not actually be see-through!
You have to set this before presenting ie setting this parameter in the viewDidLoad of the presentedViewController won't have any affect

回答3:

In iOS 8.0 and above it can be done by setting the property modalPresentationStyle to UIModalPresentationOverCurrentContext

//Set property **definesPresentationContext** YES to avoid presenting over presenting-viewController's navigation bar

self.definesPresentationContext = YES; //self is presenting view controller
presentedController.view.backgroundColor = [YOUR_COLOR with alpha OR clearColor]
presentedController.modalPresentationStyle = UIModalPresentationOverCurrentContext;

[self presentViewController:presentedController animated:YES completion:nil];

回答4:

This code works fine on iPhone under iOS6 and iOS7:

presentedVC.view.backgroundColor = YOUR_COLOR; // can be with 'alpha'
presentingVC.modalPresentationStyle = UIModalPresentationCurrentContext;
[presentingVC presentViewController:presentedVC animated:YES completion:NULL];

In this case you miss slide-on animation. To retain animation you still can use the following "non-elegant" extension:

[presentingVC presentViewController:presentedVC animated:YES completion:^{
    [presentedVC dismissViewControllerAnimated:NO completion:^{
        presentingVC.modalPresentationStyle = UIModalPresentationCurrentContext;
        [presentingVC presentViewController:presentedVC animated:NO completion:NULL];
    }];
}];

If our presentingV is located inside of UINavigationController or UITabbarController you need to operate with that controllers as presentingVC.

Further, in iOS7 you can implement custom transition animation applying UIViewControllerTransitioningDelegate protocol. Of course, in this case you can get transparent background

@interface ModalViewController : UIViewController <UIViewControllerTransitioningDelegate>

First, before presenting you have to set modalPresentationStyle

modalViewController.modalPresentationStyle = UIModalPresentationCustom;

Then you have to implement two protocol methods

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForPresentedController:(UIViewController *)presented presentingController:(UIViewController *)presenting sourceController:(UIViewController *)source
{
    CustomAnimatedTransitioning *transitioning = [CustomAnimatedTransitioning new];
    transitioning.presenting = YES;
    return transitioning;
}

- (id<UIViewControllerAnimatedTransitioning>)animationControllerForDismissedController:(UIViewController *)dismissed
{
    CustomAnimatedTransitioning * transitioning = [CustomAnimatedTransitioning new];
    transitioning.presenting = NO;
    return transitioning;
}

The last thing is to define your custom transition in CustomAnimatedTransitioning class

@interface CustomAnimatedTransitioning : NSObject <UIViewControllerAnimatedTransitioning>
@property (nonatomic) BOOL presenting;
@end

@implementation CurrentContextTransitionAnimator

- (NSTimeInterval)transitionDuration:(id <UIViewControllerContextTransitioning>)transitionContext 
{
    return 0.25;
}

- (void)animateTransition:(id <UIViewControllerContextTransitioning>)transitionContext 
{
    UIViewController *fromViewController = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController *toViewController = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

    if (self.presenting) {
        // custom presenting animation
    }
    else {
        // custom dismissing animation
    }
}

回答5:

I struggled a bit with the Interface Builder of XCode 7 to set the Presentation Style as @VenuGopalTewari suggested. In this version, there seems to be no Over Current Context or Over Full Screen presentation mode for the segue. Thus, to make it work, I set the mode to Default:

with

Additionally I set the presentation mode of the modally presented view controller to Over Full Screen:

回答6:

Create a segue to present modally and set Presentation property of that segue to over current context it will work 100 %

回答7:

PresentViewController with Transparent background - in iOS 8 and iOS 9

MYViewController *myVC = [self.storyboard   instantiateViewControllerWithIdentifier:@"MYViewController"];
    myVC.providesPresentationContextTransitionStyle = YES;
    myVC.definesPresentationContext = YES;
    [myVC setModalPresentationStyle:UIModalPresentationOverCurrentContext];
    [self.navigationController presentViewController:myVC animated:YES completion:nil];

And in MYViewController set background color black and reduce opacity

回答8:

It's a bit of hacky way, but for me this code works (iOS 6):

AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];

[self presentViewController:self.signInViewController animated:YES completion:^{
    [self.signInViewController dismissViewControllerAnimated:NO completion:^{
        appDelegate.window.rootViewController.modalPresentationStyle = UIModalPresentationCurrentContext;
        [self presentViewController:self.signInViewController animated:NO completion:nil];
        appDelegate.window.rootViewController.modalPresentationStyle = UIModalPresentationFullScreen;

    }];
}];

This code works also on iPhone

回答9:

This category worked for me (ios 7, 8 and 9)

H file

@interface UIViewController (navigation)
- (void) presentTransparentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion;
@end

M file

@implementation UIViewController (navigation)
- (void)presentTransparentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion
{
    if(SYSTEM_VERSION_LESS_THAN(@"8.0")) {
        [self presentIOS7TransparentController:viewControllerToPresent withCompletion:completion];

    }else{
        viewControllerToPresent.modalPresentationStyle = UIModalPresentationOverCurrentContext;
         [self presentViewController:viewControllerToPresent animated:YES completion:completion];
    }
}
-(void)presentIOS7TransparentController:(UIViewController *)viewControllerToPresent withCompletion:(void(^)(void))completion
{
    UIViewController *presentingVC = self;
    UIViewController *root = self;
    while (root.parentViewController) {
        root = root.parentViewController;
    }
    UIModalPresentationStyle orginalStyle = root.modalPresentationStyle;
    root.modalPresentationStyle = UIModalPresentationCurrentContext;
    [presentingVC presentViewController:viewControllerToPresent animated:YES completion:^{
        root.modalPresentationStyle = orginalStyle;
    }];
}
@end

回答10:

If you're using Storyboard, you can follow this step:

Add a view controller (V2), setup the UI the way you want it

add an UIView - set background to black and opacity to 0.5
add another UIView(2) - that will serve as your popup (Pls take note that the UIView and the UIView(2) must have the same level/hierarchy. Dont make the imageview the child of the view otherwise the opacity of the uiview will affect the UIView(2))

Present V2 Modally

Click the segue. In the Attributes inspector, Set Presentation as Over Full Screen. Remove animation if you like

Select V2. In the Attributes inspector, Set Presentation as Over Full Screen. Check Defines Context and Provides Context

Select the MainView of your V2 (Pls. Check image). Set backgroundColor to Clear Color

回答11:

The solution to this answer using swift would be as follows.

let vc = MyViewController()
vc.view.backgroundColor = UIColor.clear // or whatever color.
vc.modalPresentationStyle = .overCurrentContext
present(vc, animated: true, completion: nil)

回答12:

I added these three lines in the init method in the presented view controller, and works like a charm:

self.providesPresentationContextTransitionStyle = YES;
self.definesPresentationContext = YES;
[self setModalPresentationStyle:UIModalPresentationOverCurrentContext];

EDIT (working on iOS 9.3):

self.modalPresentationStyle = UIModalPresentationOverFullScreen;

As per documentation:

UIModalPresentationOverFullScreen A view presentation style in which the presented view covers the screen. The views beneath the presented content are not removed from the view hierarchy when the presentation finishes. So if the presented view controller does not fill the screen with opaque content, the underlying content shows through.

Available in iOS 8.0 and later.

回答13:

Alternate way is to use a "container view". Just make alpha below 1 and embed with seque. XCode 5, target iOS7. Tested on iPhone.

Container view available from iOS6. Link to blog post about that.

回答14:

I have created an object to handle the presentation of what I call a "superposed modal", meaning it retains the background's view and allows you to have a modal with a transparent background.

It has a single, simple method that does this:

- (void)presentViewController:(UIViewController *)presentedViewController
       fromViewController:(UIViewController *)presentingViewController
{
    presentedViewController.modalPresentationStyle = UIModalPresentationCustom;
    presentedViewController.transitioningDelegate = self;
    presentedViewController.modalPresentationCapturesStatusBarAppearance = YES;

    [presentedViewController setNeedsStatusBarAppearanceUpdate];

    [presentingViewController presentViewController:presentedViewController
                                       animated:YES
                                     completion:nil];
}

It's important to set the modalPresentationCapturesStatusBarAppearance property to YES and force the status bar appearance to update, if your presented view controller has a different preferredStatusBarStyle.

This object should have a @property (assign, nonatommic) isPresenting

You want this object to comply to the UIViewControllerAnimatedTransitioning and UIViewControllerTransitioningDelegate protocols and implement the following methods:

- (id)animationControllerForPresentedController:(UIViewController *)presented
                           presentingController:(UIViewController *)presenting
                               sourceController:(UIViewController *)source
{
    self.isPresenting = YES;

    return self;
}

- (id)animationControllerForDismissedController:(UIViewController *)dismissed
{
    self.isPresenting = NO;

    return self;
}

and:

- (NSTimeInterval)transitionDuration:(id)transitionContext
{
    return 0.25;
}

- (void)animateTransition:(id)transitionContext
{
    UIViewController* firstVC = [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
    UIViewController* secondVC = [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
    UIView* containerView = [transitionContext containerView];
    UIView* firstView = firstVC.view;
    UIView* secondView = secondVC.view;

    if (self.isPresenting) {
        [containerView addSubview:secondView];
        secondView.frame = (CGRect){
            containerView.frame.origin.x,
            containerView.frame.origin.y + containerView.frame.size.height,
            containerView.frame.size
        };

        firstView.tintAdjustmentMode = UIViewTintAdjustmentModeDimmed;
        [UIView animateWithDuration:0.25 animations:^{
            secondView.frame = containerView.frame;
        } completion:^(BOOL finished) {
            [transitionContext completeTransition:YES];
        }];
        } else {
        [UIView animateWithDuration:0.25 animations:^{
            firstView.frame = (CGRect){
                containerView.frame.origin.x,
                containerView.frame.origin.y + containerView.frame.size.height,
                containerView.frame.size
        };

        } completion:^(BOOL finished) {
            [transitionContext completeTransition:YES];
        }];
    }
}

This does a slide-in-from-the-bottom animation mimicking the default modal animation, but you can make it whatever you want.

The important thing is that the presenting view controller's view will remain in the back, letting you create a transparent effect.

This solution works for iOS 7+

回答15:

A very simple way of doing this (using Storyboards, for example) is:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"SomeStoryboard" bundle:nil];
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"SomeStoryboardViewController"];
// the key for what you're looking to do:
vc.modalPresentationStyle = UIModalPresentationOverCurrentContext;
vc.view.alpha = 0.50f;

[self presentViewController:vc animated:YES completion:^{
    // great success
}];

This will present a UIViewController in a Storyboard modally, but with a translucent background.

回答16:

Working for iOS 7-10

if #available(iOS 8.0, *) {
    nextVC.modalPresentationStyle = .OverCurrentContext
    self.presentViewController(nextVC, animated: true, completion: nil)
} else {
    // Fallback on earlier version
    self.modalPresentationStyle = .Custom          
    nextVC.modalTransitionStyle = .CrossDissolve            
    self.presentViewController(nextVC, animated: false, completion: nil)
    }
}

回答17:

To recap all the good answers and comments here and to still have an animation while moving to your new ViewController this is what I did: (Supports iOS 6 and up)

If your using a UINavigationController \ UITabBarController this is the way to go:

    SomeViewController *vcThatWillBeDisplayed = [self.storyboard instantiateViewControllerWithIdentifier:@"SomeVC"];

    vcThatWillBeDisplayed.view.backgroundColor = [UIColor colorWithRed: 255/255.0 green:255/255.0 blue:255/255.0 alpha:0.50];    

    self.navigationController.modalPresentationStyle = UIModalPresentationCurrentContext;
    [self presentViewController:presentedVC animated:YES completion:NULL];

If you'll do that you will lose your modalTransitionStyle animation. In order to solve it you can easily add to your SomeViewController class this:

-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    [UIView animateWithDuration:0.4 animations:^() {self.view.alpha = 1;}
       completion:^(BOOL finished){}];
}
- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.alpha = 0;
}

回答18:

Of course you should set UIModalPresentationCurrentContext, but the place to set clearColor is very important too! You can't set background in viewDidLoad function, set it before the view did load like in the root view controller or in the init function of the controller that going to present!

actionController.view.backgroundColor = [UIColor clearColor];
[self presentViewController:actionController animated:YES completion:nil];

- (instancetype)init {

    self = [super initWithNibName:nil bundle:nil];

    if(self) {
        self.modalPresentationStyle = UIModalPresentationOverCurrentContext;
        [self.view setBackgroundColor:[UIColor clearColor]];
    }

    return self;
}

回答19:

If you are using modal segue, make sure to set it as this image (you can turn off animation if you want)

回答20:

A complete method tested on iOS 7 and iOS 8.

@interface UIViewController (MBOverCurrentContextModalPresenting)

/// @warning Some method of viewControllerToPresent will called twice before iOS 8, e.g. viewWillAppear:.
- (void)MBOverCurrentContextPresentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion;

@end

@implementation UIViewController (MBOverCurrentContextModalPresenting)

- (void)MBOverCurrentContextPresentViewController:(UIViewController *)viewControllerToPresent animated:(BOOL)flag completion:(void (^)(void))completion {
    UIViewController *presentingVC = self;

    // iOS 8 before
    if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_7_1) {
        UIViewController *root = presentingVC;
        while (root.parentViewController) {
            root = root.parentViewController;
        }

        [presentingVC presentViewController:viewControllerToPresent animated:YES completion:^{
            [viewControllerToPresent dismissViewControllerAnimated:NO completion:^{
                UIModalPresentationStyle orginalStyle = root.modalPresentationStyle;
                if (orginalStyle != UIModalPresentationCurrentContext) {
                    root.modalPresentationStyle = UIModalPresentationCurrentContext;
                }
                [presentingVC presentViewController:viewControllerToPresent animated:NO completion:completion];
                if (orginalStyle != UIModalPresentationCurrentContext) {
                    root.modalPresentationStyle = orginalStyle;
                }
            }];
        }];
        return;
    }

    UIModalPresentationStyle orginalStyle = viewControllerToPresent.modalPresentationStyle;
    if (orginalStyle != UIModalPresentationOverCurrentContext) {
        viewControllerToPresent.modalPresentationStyle = UIModalPresentationOverCurrentContext;
    }
    [presentingVC presentViewController:viewControllerToPresent animated:YES completion:completion];
    if (orginalStyle != UIModalPresentationOverCurrentContext) {
        viewControllerToPresent.modalPresentationStyle = orginalStyle;
    }
}

@end

回答21:

Swift 4.2

guard let someVC = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "someVC") as? someVC else {
    return
}
someVC.modalPresentationStyle = .overCurrentContext

present(someVC, animated: true, completion: nil)

回答22:

in appdelegate :

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [[_window rootViewController]setModalPresentationStyle:UIModalPresentationCurrentContext];
    return YES;
}

in you first view controller from where you have to load next view:

  NextViewController *customvc = [[NextViewController alloc]init];
    [self presentViewController:customvc animated:YES completion:^{

    }];

in your nextViewController which is to be added transparent:

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor clearColor];
    UIView* backView = [[UIView alloc] initWithFrame:self.view.frame];
    backView.backgroundColor = [[UIColor blackColor] colorWithAlphaComponent:0.6];
    [self.view insertSubview:backView atIndex:0];
}

回答23:

The Login screen is a modal, meaning that it sits on top of the previous screen. So far we have Blurred Background, but it’s not blurring anything; it’s just a grey background.

We need to set our Modal properly.

image link target

First, we need to change the View Controller’s View background to Clear color. It simply means that it should be transparent. By default, that View is white.
Second, we need to select the Segue that leads to the Login screen, and in the Attribute Inspector, set the Presentation to Over Current Context. This option is only available with Auto Layout and Size Classes enabled.

image link target