如何在Swift中使用XIB文件初始化/实例化自定义UIView类-Java 学习之路

103

我有一个名为 MyClass 的类，它是 UIView 的子类，我想用 XIB 文件进行初始化 . 我不知道如何使用名为 View.xib 的xib文件初始化此类

class MyClass: UIView {

    // what should I do here? 
    //init(coder aDecoder: NSCoder) {} ?? 
}

9 回答

从Swift 2.0开始，您可以添加协议扩展 . 在我看来，这是一种更好的方法，因为返回类型是 Self 而不是 UIView ，因此调用者不需要强制转换为视图类 .

import UIKit

protocol UIViewLoading {}
extension UIView : UIViewLoading {}

extension UIViewLoading where Self : UIView {

  // note that this method returns an instance of type `Self`, rather than UIView
  static func loadFromNib() -> Self {
    let nibName = "\(self)".characters.split{$0 == "."}.map(String.init).last!
    let nib = UINib(nibName: nibName, bundle: nil)
    return nib.instantiateWithOwner(self, options: nil).first as! Self
  }

}

回复于 2024-05-04T20:21:24+08:00

我测试了这段代码，效果很好

class MyClass: UIView {

    class func instanceFromNib() -> UIView {
        return UINib(nibName: "nib file name", bundle: nil).instantiateWithOwner(nil, options: nil)[0] as UIView
    }

}

初始化视图并使用如下所示

var view = MyClass.instanceFromNib()
    self.view.addSubview(view)

var view = MyClass.instanceFromNib
    self.view.addSubview(view())

UDATE Swift >=3.x

class func instanceFromNib() -> UIView {
    return UINib(nibName: "nib file name", bundle: nil).instantiate(withOwner: nil, options: nil)[0] as! UIView
}

回复于 2024-05-04T20:21:24+08:00

Sam的解决方案已经很好了，尽管它没有考虑不同的捆绑（NSBundle：forClass来救援）并且需要手动加载，a.k.a打字代码 .

如果你想完全支持你的Xib Outlets，不同的Bundles（在框架中使用！）并在Storyboard中获得一个很好的预览，试试这个：

// NibLoadingView.swift
import UIKit

// Usage: Subclass your UIView from NibLoadView to automatically load a xib with the same name as your class

@IBDesignable
class NibLoadingView: UIView {

    @IBOutlet weak var view: UIView!

    override init(frame: CGRect) {
        super.init(frame: frame)
        nibSetup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        nibSetup()
    }

    private func nibSetup() {
        backgroundColor = .clearColor()

        view = loadViewFromNib()
        view.frame = bounds
        view.autoresizingMask = [.FlexibleWidth, .FlexibleHeight]
        view.translatesAutoresizingMaskIntoConstraints = true

        addSubview(view)
    }

    private func loadViewFromNib() -> UIView {
        let bundle = NSBundle(forClass: self.dynamicType)
        let nib = UINib(nibName: String(self.dynamicType), bundle: bundle)
        let nibView = nib.instantiateWithOwner(self, options: nil).first as! UIView

        return nibView
    }

}

像往常一样使用你的xib，即将Outlets连接到File Owner并将File Owner类设置为你自己的类 .

Usage: Just subclass your own View class from NibLoadingView.

不再需要其他代码 .

信用额到期的信用额度：来自DenHeadless对GH的微小变化 . 我的要点：https://gist.github.com/winkelsdorf/16c481f274134718946328b6e2c9a4d8

回复于 2024-05-04T20:21:24+08:00

这就是Frederik在Swift 3.0上的答案

@IBDesignable
class NibLoadingView: UIView {

    @IBOutlet weak var view: UIView!

    override init(frame: CGRect) {
        super.init(frame: frame)
        nibSetup()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        nibSetup()
    }

    private func nibSetup() {
        backgroundColor = .clear

        view = loadViewFromNib()
        view.frame = bounds
        view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        view.translatesAutoresizingMaskIntoConstraints = true

        addSubview(view)
    }

    private func loadViewFromNib() -> UIView {
        let bundle = Bundle(for: type(of: self))
        let nib = UINib(nibName: String(describing: type(of: self)), bundle: bundle)
        let nibView = nib.instantiate(withOwner: self, options: nil).first as! UIView

        return nibView
    }
}

回复于 2024-05-04T20:21:24+08:00

214

从xib加载视图的通用方法：

例：

let myView = Bundle.loadView(fromNib: "MyView", withType: MyView.self)

执行：

extension Bundle {

    static func loadView<T>(fromNib name: String, withType type: T.Type) -> T {
        if let view = Bundle.main.loadNibNamed(name, owner: nil, options: nil)?.first as? T {
            return view
        }

        fatalError("Could not load view with type " + String(describing: type))
    }
}

回复于 2024-05-04T20:21:24+08:00

Swift 3 Answer: 在我的情况下，我希望在我的自定义类中有一个可以修改的插座：

class MyClassView: UIView {
    @IBOutlet weak var myLabel: UILabel!

    class func createMyClassView() -> MyClass {
        let myClassNib = UINib(nibName: "MyClass", bundle: nil)
        return myClassNib.instantiate(withOwner: nil, options: nil)[0] as! MyClassView
    }
}

在.xib中时，请确保“自定义类”字段为MyClassView . 不要打扰文件所有者 .

Make sure Custom Class is MyClassView

此外，请确保将MyClassView中的插座连接到标签：
Outlet for myLabel

要实例化它：

let myClassView = MyClassView.createMyClassView()
myClassView.myLabel.text = "Hello World!"

回复于 2024-05-04T20:21:24+08:00

Swift 4

在我的情况下，我必须将数据传递到该自定义视图，因此我创建静态函数来实例化视图 .

创建UIView扩展

extension UIView {
    class func initFromNib<T: UIView>() -> T {
        return Bundle.main.loadNibNamed(String(describing: self), owner: nil, options: nil)?[0] as! T
    }
}

创建MyCustomView

class MyCustomView: UIView {

    @IBOutlet weak var messageLabel: UILabel!

    static func instantiate(message: String) -> MyCustomView {
        let view: MyCustomView = initFromNib()
        view.messageLabel.text = message
        return view
    }
}

在.xib文件中将自定义类设置为MyCustomView . 如有必要，照常连接插座 .
实例化视图

let view = MyCustomView.instantiate(message: "Hello World.")

回复于 2024-05-04T20:21:24+08:00

1

有一些框架实现了在此页面上多次提到的相同代码 .

我正在发布其中一个这样的框架，LoadableViews .

由于这个框架已经在MLSDev的几乎所有应用程序中使用，我正在研究的公司，它将在可预见的未来得到积极支持 .

只是发布在这里感兴趣的人 .

回复于 2024-05-04T20:21:24+08:00

override func draw(_ rect: CGRect) 
{
    AlertView.layer.cornerRadius = 4
    AlertView.clipsToBounds = true

    btnOk.layer.cornerRadius = 4
    btnOk.clipsToBounds = true   
}

class func instanceFromNib() -> LAAlertView {
    return UINib(nibName: "LAAlertView", bundle: nil).instantiate(withOwner: nil, options: nil)[0] as! LAAlertView
}

@IBAction func okBtnDidClicked(_ sender: Any) {

    removeAlertViewFromWindow()

    UIView.animate(withDuration: 0.4, delay: 0.0, options: .allowAnimatedContent, animations: {() -> Void in
        self.AlertView.transform = CGAffineTransform(scaleX: 0.1, y: 0.1)

    }, completion: {(finished: Bool) -> Void in
        self.AlertView.transform = CGAffineTransform.identity
        self.AlertView.transform = CGAffineTransform(scaleX: 0.0, y: 0.0)
        self.AlertView.isHidden = true
        self.AlertView.alpha = 0.0

        self.alpha = 0.5
    })
}


func removeAlertViewFromWindow()
{
    for subview  in (appDel.window?.subviews)! {
        if subview.tag == 500500{
            subview.removeFromSuperview()
        }
    }
}


public func openAlertView(title:String , string : String ){

    lblTital.text  = title
    txtView.text  = string

    self.frame = CGRect(x: 0, y: 0, width: screenWidth, height: screenHeight)
    appDel.window!.addSubview(self)


    AlertView.alpha = 1.0
    AlertView.isHidden = false

    UIView.animate(withDuration: 0.2, animations: {() -> Void in
        self.alpha = 1.0
    })
    AlertView.transform = CGAffineTransform(scaleX: 0.0, y: 0.0)

    UIView.animate(withDuration: 0.3, delay: 0.2, options: .allowAnimatedContent, animations: {() -> Void in
        self.AlertView.transform = CGAffineTransform(scaleX: 1.1, y: 1.1)

    }, completion: {(finished: Bool) -> Void in
        UIView.animate(withDuration: 0.2, animations: {() -> Void in
            self.AlertView.transform = CGAffineTransform(scaleX: 1.0, y: 1.0)

        })
    })


}

回复于 2024-05-04T20:21:24+08:00

如何在Swift中使用XIB文件初始化/实例化自定义UIView类

9 回答

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