如何移除Swift音频录制代码中的强制解包操作？

我来帮你一步步把代码里的强制解包都去掉，让代码更健壮、更安全～先看你给出的原始代码，里面有几处!强制解包，这些操作很容易触发运行时崩溃，我们可以用Swift的可选绑定、可选链来替换它们。

原始代码 #

var recorder : Recorder? = nil
func startAudioRecording() {
    if recorder == nil {
        recorder = Recorder()
    }
    if !recorder!.isRunning() {
        recorder?.startRecording({ [weak self] audioData in
            self?.remoteInterface?.sendVoice(audioData.0)
        }, withCompletionBlock: { (_) in
        })
    }
}
func stopAudioRecording(_ keyCommand: String!){
    if let _ = recorder {
        if(recorder?.isRunning())! {
            recorder?.stopRecording(completionBlock: { (isFinished: Bool) in
                DispatchQueue.global().asyncAfter(deadline: DispatchTime.now() + Double(Int64(1 * NSEC_PER_MSEC)) / Double(NSEC_PER_SEC), execute: { [unowned self] in
                    self.remoteInterface?.sendTouchUp(keyCommand)
                    self.audioRecorder = nil // 这里应该是笔误，原变量名是recorder
                })
            })
        }
    }
}

逐点修改说明 #

• 处理startAudioRecording中的强制解包：
  原代码里if !recorder!.isRunning()直接强制解包recorder，我们可以用可选绑定先确保recorder存在，再检查运行状态，这样既安全又清晰：

  guard let recorder = recorder else { return }
  if !recorder.isRunning() {
      recorder.startRecording({ [weak self] audioData in
          self?.remoteInterface?.sendVoice(audioData.0)
      }, withCompletionBlock: { (_) in
      })
  }
  

• 处理stopAudioRecording中的强制解包：
  原代码里if(recorder?.isRunning())!的强制解包同样危险，我们可以用guard语句一次性完成「recorder存在」和「正在运行」两个条件的检查，不符合就直接返回，代码逻辑更紧凑：

  guard let recorder = recorder, recorder.isRunning() else { return }
  recorder.stopRecording(completionBlock: { [unowned self] isFinished in
      DispatchQueue.global().asyncAfter(deadline: .now() + 0.001) {
          self.remoteInterface?.sendTouchUp(keyCommand)
          self.recorder = nil // 修正笔误，把audioRecorder改成recorder
      }
  })
  

  另外还简化了延迟执行的语法，让代码更易读。

修改后的完整代码 #

var recorder: Recorder? = nil

func startAudioRecording() {
    if recorder == nil {
        recorder = Recorder()
    }
    // 可选绑定避免强制解包
    guard let recorder = recorder else { return }
    if !recorder.isRunning() {
        recorder.startRecording({ [weak self] audioData in
            self?.remoteInterface?.sendVoice(audioData.0)
        }, withCompletionBlock: { (_) in
        })
    }
}

func stopAudioRecording(_ keyCommand: String!) {
    // 一次性检查recorder状态，不符合直接返回
    guard let recorder = recorder, recorder.isRunning() else { return }
    recorder.stopRecording(completionBlock: { [unowned self] isFinished in
        DispatchQueue.global().asyncAfter(deadline: .now() + 0.001) {
            self.remoteInterface?.sendTouchUp(keyCommand)
            self.recorder = nil
        }
    })
}

现在代码里已经没有任何强制解包操作了，运行时的崩溃风险大大降低，同时可读性也更好～

内容的提问来源于stack exchange，提问作者Sanoj Kashyap