Mobile Development Articles - Page 149 of 156

To add a UISegmentControl in iOS with swift we’ll have to first create a segment control and it’s controller function, i.e. it’s action. Let’s see those steps.Let’s create a function to add a segmented control.func addControl() {    let segmentItems = ["First", "Second"]    let control = UISegmentedControl(items: segmentItems) control.frame = CGRect(x: 10, y: 250, width: (self.view.frame.width - 20), height: 50) control.addTarget(self, action: #selector(segmentControl(_:)), for: .valueChanged) control.selectedSegmentIndex = 1 view.addSubview(control) }This function may be called in our view controller to add the segmented control, let’s add action for ... Read More

To change the background color of a button in iOS application we need to access the property ‘ backgroundColor’ of the UIButton. We can do this in two ways, programmatically and using the storyboard.Method 1 − Using the storyboard editorAdd a button on your storyboard, select it Go to it’s attribute inspector and select 'Background' property to choose the color.Method 2 − Programmatically changing the backgroundCreate outlet of the button on the View Controller.In the viewDidLoad() or viewWillLayoutSubview() method add the code to change the background color.btn.backgroundColor = #colorLiteral(red: 0.4392156899, green: 0.01176470611, blue: 0.1921568662, alpha: 1)When we run the method ... Read More

In this article we’ll see how to open a pdf file using swift in iOS. Here we’ll do it with an example of opening pdf in webView in iOS. Let’s create a project and add WKWebView to the storyboard.Connect it’s outlet to the ViewController class.Now we’ll see two different thingsOpening a PDF file from a URL on the web.To open a web view from a url, first we need to have a url with a pdf file. In this example I’ll be using a dummy URL https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdfLet’s create a URL first, let url: URL! = URL(string: "https://www.w3.org/WAI/ER/tests/xhtml/testfiles/resources/pdf/dummy.pdf")Now the remaining steps ... Read More

To make an iPhone vibrate using swift we’ll use two different methods. First create a new project and add Four different buttons to the main View controller.Now import the AudioToolbox framework in your view controller class.For the first button add an action and write the following code as shown below:@IBAction func actionButtonOne(_ sender: Any) {    AudioServicesPlayAlertSound(SystemSoundID(kSystemSoundID_Vibrate)) }This will generate a long vibrating feedback on your device. Now to create more vibration effects on devices with iOS 10 or more we’ll add methods for all four different buttons.@IBAction func actionButtonTwo(_ sender: Any) {    let generator = UIImpactFeedbackGenerator(style: .heavy)   ... Read More

To replace a character in objective C we will have to use the inbuilt function of Objective C string library, which replaces occurrence of a string with some other string that we want to replace it with.To create a string in objective C we need to write −NSString *str = @"tutori@als";Now we have a choice of replacing characters in this string and creating new one, or modify this same string. In this example we will modify this string and print in the next line.str = [str stringByReplacingOccurrencesOfString:@"@" withString:@""]; NSLog(@”%@”, str);When we run the above code, str is replaced with “tutorials” ... Read More

To download a video from a URL in swift we need to perform a few steps while keeping a few things in mind.Points to be noted here are, We’ll be making use of internet to download video, hence we need to allow permissions for App transport security in our Info.plistWe’ll need to save the downloaded video to Photos app, hence photos permission is required.Video should always be downloaded in background as it may prevent us from using the app if downloaded on foreground.Now, we’ll use the below code to save a video from a random link in our Device. You’ll ... Read More

To add a live camera preview to our default UIView in swift we can either use AVFoundation framework of iOS SDK or native UIImagePickerController(). In this example we’ll be using ImagePicker as our aim is to present camera preview on the UIView and Imagepicker is suitable for that task. AVFoundation can be used when we need a lot of customization on our camera or different types of custom actions.To show a camera preview on the UIView we need to perform the following steps.Create a UIImagePickerController object.Conform our class to UIImagePickerControllerDelegate and UINavigationControllerDelegate.Assign delegates to the object we created in step ... Read More

Bitcode – Bitcode is an intermediate reperesentation of how the code looks. This code can not be used by us or can’t be installed on a device. When we upload our application to the app store It is uploaded as an bitcode and later converted to app binary by itunes/Apple.When the Intermediate code is created an uploaded to the App store or run on the device, a program called LLMV takes over the control and converts the Intermediate code to a Binary file which is x86 32Bit or x86 64 bit for the simulator and ARM for the actual iOS handheld ... Read More

Processing symbol files is a message displayed on xcode when we create a project’s build. When this message appears, in background Xcode downloads files and symbol files for specific device and a specific processor on which build shall be installed.The symbol files contains debug symbols which are used to debug on specific processor and iOS version and when some crash or error occurs, those symbols are used to create crash reports. Once processing symbols is done a new folder with device symbols is created in the library, usually under “~/Library/Developer/Xcode/iOS DeviceSupport/ “.Sometimes our system might get stuck on this step ... Read More

When we build an iOS application, by default it get a version 1.0 and build 0. Whenever we upload a new build to the app store, we need to change the version number. We can update the build number for testing builds. The version and build number are stored in the info.plist file in our project.Sometimes we might need to access the build or the version number in our application to perform some custom action.To get the version number we can use the following code and assign it to a variable or constant.Bundle.main.object(forInfoDictionaryKey: "CFBundleShortVersionString") as! StringTo get the build number ... Read More