Skip to main content

Đẩy TextField lên trên bàn phím

Chúng ta có một vấn đề như thế này: nếu Text Field ở gần phía đấy màn hình, khi keyboard được bật lên nó sẽ che mốt ô text cần nhập. Chúng ta sẽ cần xử lý để đẩy ô Text Field lên phía trên của Key board



Chúng ta sẽ phải lắng nghe sự kiện ẩn, hiện của keyboard

 NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillShow(notification:)), name: .UIKeyboardWillShow, object: nil) 
NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillHide(notification:)), name: .UIKeyboardWillHide, object: nil)

@objc func keyboardWillShow(notification: NSNotification) {
        if let keyboardSize = (notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue {
            guard let globalPoint =  textField.superview?.convert(textField.frame.origin, to: nil) else {
                return
            }
            if globalPoint.y + 50 > heightScreen - keyboardSize.height {
                distanceConstraint.constant = CGFloat(keyboardSize.height - (heightScreen - globalPoint.y) + 50)
            }
        }
    }

    @objc func keyboardWillHide(notification: NSNotification) {
        if distanceConstraint.constant > 0 {
            distanceConstraint.constant = CGFloat(0)
        }
    }


textField : Text Field cuối cùng

textField.superview?.convert : là câu lệnh để quy đổi tới hệ toạ độ trên màn hình
50 : là chiều cao của Text Field 40dp công thêm một khoảng 10dp

Comments

Popular posts from this blog

Alamofire vs URLSession

Alamofire vs URLSession: a comparison for networking in Swift Alamofire and URLSession both help you to make network requests in Swift. The URLSession API is part of the foundation framework, whereas Alamofire needs to be added as an external dependency. Many  developers  doubt  whether it’s needed to include an extra dependency on something basic like networking in Swift. In the end, it’s perfectly doable to implement a networking layer with the great URLSession API’s which are available nowadays. This blog post is here to compare both frameworks and to find out when to add Alamofire as an external dependency. Build better iOS apps faster Looking for a great mobile CI/CD solution that has tons of iOS-specific tools, smooth code signing, and even real device testing? Learn more about Bitrise’s iOS specific solutions! This shows the real power of Alamofire as the framework makes a lot of things easier. What is Alamofire? Where URLSession...

Swift Tool Belt, Part 1: Adding a Border, Corner Radius, and Shadow to a UIView with Interface Builder

During my iOS work, I’ve assembled a set of code that I bring with me on every iOS project. I’m not talking about large frameworks or CocoaPods here. These are smaller Swift extensions or control overrides that are applicable to many projects. I think of them as my tool belt. In this post, I’ll show you an extension that will add a border, a corner radius, and a shadow to any UIView, UIButton, or UILabel and allow you to preview what it will look like in Interface Builder. Back in 2014, I wrote a blog post on Expanding User-Defined Runtime Attributes in Xcode where I added a border, corner radius, and shadow to a UIView using Interface Builder’s user-defined runtime attributes. This solution had no type checking—you had to type the property you wanted to modify by hand and often had to look up what it was called. You also had to run your project in order to see the effect of the runtime attribute. Starting with Xcode 6 , there is a new mech...

Frame vs Bounds in iOS

This article is a repost of an answer I wrote on Stack Overflow . Short description frame = a view’s location and size using the parent view’s coordinate system ( important for placing the view in the parent) bounds = a view’s location and size using its own coordinate system (important for placing the view’s content or subviews within itself) Details To help me remember frame , I think of a picture frame on a wall . The picture frame is like the border of a view. I can hang the picture anywhere I want on the wall. In the same way, I can put a view anywhere I want inside a parent view (also called a superview). The parent view is like the wall. The origin of the coordinate system in iOS is the top left. We can put our view at the origin of the superview by setting the view frame’s x-y coordinates to (0, 0), which is like hanging our picture in the very top left corner of the wall. To move it right, increase x, to move it down increase y. To help me remember bound...