如何让一个PHFComposeBarView控件在Swift iOS应用程序中变为活动状态？

Question

作为iOS开发的相对noob，我很难让PHFComposeBarView控件在我的Swift iOS应用程序中变得活跃。

在[{3}}和PHFComposeBarView example app中眯着眼睛看着Obj-C，我尽力将基本设置翻译成Swift，以便控件显示在主视图中：

但是，我还没有设法让控件以编程方式变为活动状态。

我在Swift 2.0 / XCode 7.0 Beta 2中创建了一个this SO answer，其ViewController如下所示：

ViewController.swift：

import UIKit
import PHFComposeBarView

class ViewController: UIViewController, PHFComposeBarViewDelegate {

    var composeBar: PHFComposeBarView {
        let viewBounds = self.view.bounds
        let frame = CGRectMake(0.0, viewBounds.size.height - PHFComposeBarViewInitialHeight, viewBounds.size.width, PHFComposeBarViewInitialHeight)
        let composeBarView = PHFComposeBarView(frame: frame)
        composeBarView.delegate = self
        return composeBarView
    }

    override var inputAccessoryView: UIView {
        return self.composeBar
    }

    override func canBecomeFirstResponder() -> Bool {
        return true
    }

    override func viewDidAppear(animated: Bool) {
        print("viewDidAppear self \(self)")
        print("composeBar.delegate \(self.composeBar.delegate)")
        print("composeBar.textView.delegate \(self.composeBar.textView.delegate)")
        print("composeBar.canBecomeFirstResponder() \(self.composeBar.canBecomeFirstResponder())")
        print("composeBar.textView.canBecomeFirstResponder() \(self.composeBar.textView.canBecomeFirstResponder())")
        let res = self.composeBar.becomeFirstResponder()
        print("composeBar.becomeFirstResponder() \(res)")
        print("composeBar.isFirstResponder() \(self.composeBar.isFirstResponder())")
        print("composeBar.textView.isFirstResponder() \(self.composeBar.textView.isFirstResponder())")
    }

}

控制台：

viewDidAppear self <SwiftPHFComposeBarTest.ViewController: 0x7fe088619d90>
composeBar.delegate Optional(<SwiftPHFComposeBarTest.ViewController: 0x7fe088619d90>)
composeBar.textView.delegate Optional(<PHFDelegateChain: 0x7fe088654850>)
composeBar.canBecomeFirstResponder() true
composeBar.textView.canBecomeFirstResponder() true
composeBar.becomeFirstResponder() false
composeBar.isFirstResponder() false
composeBar.textView.isFirstResponder() false

composeBar.canBecomeFirstResponder()如何返回true但composeBar.becomeFirstResponder()返回false怎么办？

另外，我不确定该委托是否是一个问题。

编辑：已更新以包含调试输出。

Answer 1

好吧，一个解决方案似乎是use the storyboard instead：

ViewController.swift：

import UIKit
import PHFComposeBarView

class ViewController: UIViewController, PHFComposeBarViewDelegate {

    @IBOutlet weak var composeBarView: PHFComposeBarView!

    override func viewDidLoad() {
        super.viewDidLoad()
        composeBarView.delegate = self
    }

    override func canBecomeFirstResponder() -> Bool {
        return true
    }

    override var inputAccessoryView: UIView {
        composeBarView.removeFromSuperview()
        return composeBarView
    }

}