ios

问题 I'm using AVMutableComposition and AVAssetExportSession to trim a video down. Randomly, and I mean randomly (I cannot consistently reproduce) users' videos have a few black frames at the start of the trimmed video. The audio is unaffected. I can confirm 100% that the videos being trimmed don't have anything to do with it, as this happens for a wide variety of videos from all different sources. Any insight into why these videos are being exported with black frames in the start would be very

问题 I am using a CADisplayLink to do a view animation that just interpolates a value and redraws the view itself. e.g. I have a view MyView and it has a property value , whenever value is set I call setNeedsDisplay and the view knows what to draw. to animate this I use CADisplayLink and I want the view to 'morph' between values. I do this by just interpolating the value from the animation's start and stop Value: - (CGFloat)interpolatedValue:(CGFloat)sourceValue withValue:(CGFloat)targetValue

问题 I have UITableView with hided separator line, and when I dragging cell, shadows appears some kind as borders comes out on up and down. How to hide this? Please see example: Great thanks! 回答1: So, I have answer, just subclass of UITableView with method: - (void) didAddSubview:(UIView *)subview { [super didAddSubview:subview]; if([subview.class.description isEqualToString:@"UIShadowView"]) { subview.hidden = YES; } } 回答2: NoShadowTableView.m #import "NoShadowTableView.h" @interface

问题 I have UITableView with hided separator line, and when I dragging cell, shadows appears some kind as borders comes out on up and down. How to hide this? Please see example: Great thanks! 回答1: So, I have answer, just subclass of UITableView with method: - (void) didAddSubview:(UIView *)subview { [super didAddSubview:subview]; if([subview.class.description isEqualToString:@"UIShadowView"]) { subview.hidden = YES; } } 回答2: NoShadowTableView.m #import "NoShadowTableView.h" @interface

问题 I wanted to perform two A/B tests on an app using Firebase A/B Testing with Remote Config. The problem is that the two tests audiences should be mutually exclusive. Forming part of both experiments might pollute the results. I've thought in setting a Firebase Analytics user property when the user enters in the Experiment 1 and excluding this property value from Experiment 2 audience, but I'm afraid that the user enters in both experiments simultaneously when fetching the Remote Config values.

问题 I wanted to perform two A/B tests on an app using Firebase A/B Testing with Remote Config. The problem is that the two tests audiences should be mutually exclusive. Forming part of both experiments might pollute the results. I've thought in setting a Firebase Analytics user property when the user enters in the Experiment 1 and excluding this property value from Experiment 2 audience, but I'm afraid that the user enters in both experiments simultaneously when fetching the Remote Config values.

问题 My home viewcontroller is Tabbarcontroller From tabbar i navigate to (A) Viewcontroller (TabarViewcontroller -> A (Viewcontroller) From A (Viewcontroller) i push (B) Viewcontroller From B (Viewcontroller) i Present (C) Viewcontroller When i dismiss (c) Viewcontroller i want to show (A) Viewcontroller or (Home) TabbarviewController So, I want to first dismiss presented viewcontroller and then I want to pop my previous pushed controller Here is my navigation flow From Tabbarviewcontroller 1-

问题 My home viewcontroller is Tabbarcontroller From tabbar i navigate to (A) Viewcontroller (TabarViewcontroller -> A (Viewcontroller) From A (Viewcontroller) i push (B) Viewcontroller From B (Viewcontroller) i Present (C) Viewcontroller When i dismiss (c) Viewcontroller i want to show (A) Viewcontroller or (Home) TabbarviewController So, I want to first dismiss presented viewcontroller and then I want to pop my previous pushed controller Here is my navigation flow From Tabbarviewcontroller 1-

问题 I've been working on an app within Xcode that runs fine on the simulator. I wanted to try it on my device. However, I've been encountering a frustratingly vague issue every time I try to install/run it on my device. The installation fails and the message I get includes: Unable to install "AppName" Domain: com.apple.dtdevicekit Code: -402620415 -- App installation failed Domain: com.apple.dtdevicekit Code: -402620415 Failure Reason: An unknown error has occurred. The target deployment is set

问题 I'd like to subclass MKCircle (e.g. MyCircle ) by adding another String property, let's call it " code ". This property shall not be an optional and constant, so I have to set it from an initializer, right? Of course MyCircle should also get center coordinate and the radius. These two properties are read-only, so I also need to set them via initializer. In the end I need an initializer that takes 3 parameters: coordinate , radius and code . Sounds pretty easy but Swifts designated and