ios - 自定义类 View 和选择器引用

Question

我正在制作一个自定义类，它只具有一些基本功能，一旦该类在任何 viewController 中初始化，我就可以重用它。问题是我不知道如何引用 View 或 #selector 中调用的任何函数，并且收到错误:使用未解析的标识符“ View ”。有人知道这是怎么做到的吗？下面的示例是创建一个新的 UIButton。

import Foundation
import UIKit

class Utils {

var newUpdatesBtn: UIButton!

func setupButtonNewUpdates() {
    newUpdatesBtn = UIButton(type: UIButtonType.System) // .System
    newUpdatesBtn.setTitle("New Updates", forState: UIControlState.Normal)
    newUpdatesBtn.bounds = CGRect(x: 0, y: 0, width: 123, height: 27)
    newUpdatesBtn.center = CGPoint(x: view.bounds.width / 2, y: 90) // 80 point button, 20 point status bar, 40 point half button, 8 point margins
    newUpdatesBtn.setBackgroundImage(UIImage(named: "new-updates"), forState: UIControlState.Normal)
    newUpdatesBtn.titleLabel?.font = UIFont.systemFontOfSize(14)
    newUpdatesBtn.setTitleColor(UIColor.whiteColor(), forState: UIControlState.Normal)
    newUpdatesBtn.addTarget(self, action: #selector(newUpdatesButtonPressed), forControlEvents: UIControlEvents.TouchUpInside)
    self.newUpdatesBtn.alpha = 0;
    self.navigationController!.view.addSubview(newUpdatesBtn)
    UIView.animateWithDuration(0.3, animations: { () -> Void in
        self.newUpdatesBtn.alpha = 1;
    })
}

}

(问题行)

View .bounds.width

newUpdatesBtn.addTarget(self, action: #selector(newUpdatesButtonPressed), forControlEvents: UIControlEvents.TouchUpInside)

Answer 1

这是因为您没有在 View 属性中设置任何引用。你可以这样做:

func setupButtonNewUpdates(targetView:UIView)
{
newUpdatesBtn = UIButton(type: UIButtonType.System) // .System
.
.
.
newUpdatesBtn.center = CGPoint(x: targetView.bounds.width / 2, y: 90) // 80 point button, 20 point status bar, 40 point half button, 8 point margins
.
.
.
targetView.addSubView(newUpdatesBtn);
}

现在，无论何时从任何 View Controller 调用此方法，只需传递该 VC 的 View 即可。例如:

var util:Utils = new Utils();
util.setupButtonNewUpdates(self.view);