cocoa-touch

问题 I'm having my first experience with CALayers , and am no doubt doing something very simple, very wrong. The below code is in a class extended from a UIView . I am accessing the CALayer of the view, which is fine, and the attempting to attach a sublayer, based on a line drawn by the users touch. (The CGPath ) By setting the background to bright orange, I can see that I'm passing the right CALayer into my function, yet if I try and set the CAShapeLayer *line to orange - I don't seem to be able

问题 I'm having my first experience with CALayers , and am no doubt doing something very simple, very wrong. The below code is in a class extended from a UIView . I am accessing the CALayer of the view, which is fine, and the attempting to attach a sublayer, based on a line drawn by the users touch. (The CGPath ) By setting the background to bright orange, I can see that I'm passing the right CALayer into my function, yet if I try and set the CAShapeLayer *line to orange - I don't seem to be able

问题 I'm adding a cameraOverlay to my UIImagePickerController, it shows and all but it doesn't register touches. I init a button in the viewDidLoad and a one via IB. Is there some rule that prohibits me from adding a UIButton to a cameraOverlayView and register touches? Thanks 回答1: I had a similar problem, and it turned out that my overlay UIView's frame was not large enough. The clipsToBounds property for a UIView is by default set to NO, which means its subviews are still visible even if they

问题 I just want my buttons to have equal spaces to each other and a fixed trailing and leading space. I am kinda Autolayout noob, so I don't have any clue how to solve this problem. I tried a lot of different configurations but nothing worked as it should. Any ideas how to solve this Issue ? UPDATE In year 2018 StackViews are the answer. 回答1: To lay out several views that are proportionally spaced based on the orientation of a device, create spacer views between the visible views. Set the

问题 I have a Music App I am developing, and while I'm managing the TableViews, I'm sorting them into Sections. This is usually an easy process, but the with the way I manage I manage the data, it might not be a completely simple task. I know it's not the best way to do it, but as the cell has multiple properties (titleLabel, textLabel, imageView), I store all the data in 3 separate arrays. When organising the songs by title, for section header, I use a predicate to set the titleLabel, so by using

问题 I've got a storyboard with a view wrapped in a navigationcontroller, that has a UI tab bar at the bottom. I dynamically add sub views to this view, but there is always a blank line between the navigation bar and the subview that appears to be the width of a status bar. On each of the subviews that are created on the storyboard I have their Simulated Metrics set to have a bottom bar as a Tab Bar, status bar is set to none, and top bar is set to navigation bar. Below is my code for adding the

问题 1.I use below code for take screenshot.is it necessary to change it for high resolution UIGraphicsBeginImageContext(self.view.bounds.size); [self.view.window.layer renderInContext:UIGraphicsGetCurrentContext()]; UIImage *viewImage = UIGraphicsGetImageFromCurrentImageContext(); UIGraphicsEndImageContext(); 2.what does happen if i just use one image with 640*960 resolution for both low and high quality ? (means that don't use image with @2x) 回答1: That will only take normal (320x480) resolution

问题 I'm new to programming for the iPhone and i'm wondering: how extensible are the various controls? Let's take the button as an example: can i change the background graphic? can i make it grow larger when i press on it? can i change the font? can i use a custom font? can i use a button graphic in place of text? 回答1: In general, yes to all your questions. You can subclass the various UI* classes that make up the Cocoa touch controls just like any other classes, and add your own custom

问题 I'm new to programming for the iPhone and i'm wondering: how extensible are the various controls? Let's take the button as an example: can i change the background graphic? can i make it grow larger when i press on it? can i change the font? can i use a custom font? can i use a button graphic in place of text? 回答1: In general, yes to all your questions. You can subclass the various UI* classes that make up the Cocoa touch controls just like any other classes, and add your own custom

问题 I dont have a very good understanding on the topic, so please bear with me I am trying to display a UIViewController inside another UIViewController. I feel like there aren't enough examples out there. I have read the documentation but being fairly new to iOS I am kind of lost. Here is my problem: I can get the child UIViewController to appear inside the parent UIViewController but the child view is not displaying right. Sorry, I cant post pictures yet. Here is my child - UIViewController.