Building a Custom Keyboard Extension in iOS App Development

In iOS app development, we often come across situations where we need to provide our users with a custom keyboard for input. Whether it's for special characters, emojis, or even a game, a custom keyboard extension can greatly enhance the user experience. In this blog post, we will explore how to build a custom keyboard extension in iOS.

Setting up the Project

To begin, create a new iOS app project in Xcode. Make sure to choose the "Keyboard Extension" template under the "Application" section. This template provides a basic structure for the keyboard extension.

Designing the Keyboard

The next step is to design the keyboard interface. Open the "MainInterface.storyboard" file to create the layout. You can add buttons, labels, or any other UI elements that you want to include in your custom keyboard. Customize the interface to align with your app's design and functionality.

Handling User Input

To handle user input, we need to implement UIInputViewController, which is the base class for keyboard extensions. Create a new Swift file and subclass UIInputViewController:

import UIKit

class CustomKeyboardViewController: UIInputViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // Load the keyboard interface from the storyboard
        let nib = UINib(nibName: "MainInterface", bundle: nil)
        let objects = nib.instantiate(withOwner: self, options: nil)
        let keyboardView = objects.first as! UIView
        self.view = keyboardView
    }
    
    @IBAction func keyTapped(_ sender: UIButton) {
        // Handle button taps here
    }
}

In the above code, we load the keyboard interface from the storyboard and set it as the view of our UIInputViewController. We also add an IBAction function to handle button taps.

Enabling the Keyboard Extension

To enable the custom keyboard extension, we need to add it to our app's capabilities. Open the "Capabilities" tab in Xcode and enable the "App Groups" capability. Add a new app group and remember the group name.

Next, open the "Info.plist" file of your keyboard extension target and add the following key-value pair:

<key>NSExtension</key>
<dict>
    <key>NSExtensionAttributes</key>
    <dict>
        <key>IsASecureTextInput</key>
        <integer>0</integer>
    </dict>
    <key>NSExtensionMainStoryboard</key>
    <string>MainInterface</string>
    <key>NSExtensionPrincipalClass</key>
    <string>$(PRODUCT_MODULE_NAME).CustomKeyboardViewController</string>
</dict>

Replace PRODUCT_MODULE_NAME with your app's module name and CustomKeyboardViewController with the name of your custom view controller class.

Finally, navigate to your app's target settings and add the app group identifier to the "Application Extensions" section.

Testing the Keyboard Extension

To test the custom keyboard extension, run the app on a physical device. Go to the Settings app, navigate to "General" > "Keyboard" > "Keyboards", and add your custom keyboard. Allow full access for the keyboard extension to work seamlessly.

Conclusion

Building a custom keyboard extension in iOS app development allows us to provide a unique and tailored input experience for our users. By following the steps outlined in this blog post, you can easily create and integrate a custom keyboard extension into your iOS app. Remember to design the keyboard interface, handle user input, enable the extension capabilities, and test it on a physical device. Happy coding!

本文来自极简博客，作者：柠檬微凉，转载请注明原文链接：Building a Custom Keyboard Extension in iOS App Development