语音指令是AI时代必不可少的技能

目前在汽车导航、智能家电领域已经得到广泛应用。是未来编程的必备技术之一。
语音指令是打开视图、控制对象、控制无人机、机器人、智能装备等非常简便的方法。可以避免导航结构、视图层级等限制，快速达成用户预期的目的。

下面我们来看看Swift如何实现语音指令。

第1步： 配置info.plist

需要获利用户授权，才能使用话筒与语音识别

image.png

image.png

第2步： 获取用户授权

import Speech

func requestSpeechRecognitionAuthorization() {
    SFSpeechRecognizer.requestAuthorization { authStatus in
        switch authStatus {
        case .authorized:
            print("用户已授权语音识别")
        case .denied:
            print("用户拒绝了语音识别权限")
        case .restricted:
            print("语音识别受限")
        case .notDetermined:
            print("用户尚未做出选择")
        @unknown default:
            print("未知状态")
        }
    }
}

第3步： 定义Speech服务

import Foundation
import Speech

class SpeechRecognitionManager: ObservableObject {
let speechRecognizer = SFSpeechRecognizer(locale: Locale(identifier: "zh-CN")) // 使用中文语音识别
let audioEngine = AVAudioEngine()
var recognitionRequest: SFSpeechAudioBufferRecognitionRequest?
var recognitionTask: SFSpeechRecognitionTask?

@Published var recognizedCommand = [String]()

func stopRecording() {
    // 停止语音识别任务
    recognitionTask?.cancel()
    
    // 停止音频引擎
    audioEngine.stop()
    recognitionRequest?.endAudio()
}


func startRecording() throws{
    
    var commands = [String]()
    // 创建语音识别请求
    recognitionRequest = SFSpeechAudioBufferRecognitionRequest()
    
    
    // 准备语音识别任务
    guard let recognitionRequest = recognitionRequest else {
        fatalError("无法创建 SFSpeechAudioBufferRecognitionRequest 实例")
    }
    
    recognitionRequest.shouldReportPartialResults = true
    
    // 启动语音识别任务
    recognitionTask = speechRecognizer?.recognitionTask(with: recognitionRequest, resultHandler: { result, error in
        // 处理识别结果
        if let result = result {
                // 处理识别结果
                let bestTranscription = result.bestTranscription
                let words = bestTranscription.segments
            
            if let lastWord = words.last {
                let recognizedWord = lastWord.substring
                // 检查识别结果是否已经获取过，如果没有则添加到 commands，并添加到 recognizedWords 中
                if !commands.contains(recognizedWord) {
                    commands.append(recognizedWord)
                }
            }

            if let command = commands.last {
                self.recognizedCommand.append(command)
            }
   
            
        } else if let error = error {
            print("识别错误: \(error)")
        }
    })
    
    // 启动音频引擎
    let audioSession = AVAudioSession.sharedInstance()
    try audioSession.setCategory(.record, mode: .measurement, options: .duckOthers)
    try audioSession.setMode(.measurement)
    try audioSession.setActive(true, options: .notifyOthersOnDeactivation)
    
    let inputNode = audioEngine.inputNode
    let recordingFormat = inputNode.inputFormat(forBus: 0)
    
    inputNode.installTap(onBus: 0, bufferSize: 1024, format: recordingFormat) { buffer, _ in
        recognitionRequest.append(buffer)
    }
    
    audioEngine.prepare()
    try audioEngine.start()
}

}

第4步： 调用服务进行语音识别

struct SpeechRecognitionView: View {
    @State private var recognizedText = ""
    
    @StateObject private var speechRecognitionManager = SpeechRecognitionManager()
    
    @State var isRecording = false
    
    var body: some View {
        VStack {
            Button(action: {
                isRecording.toggle()
                if isRecording {
                    do {
                        try speechRecognitionManager.startRecording()
                        recognizedText = speechRecognitionManager.recognizedCommand
                        
                    } catch {
                        print("启动语音识别失败: \(error)")
                    }
                } else {
                    speechRecognitionManager.stopRecording()
                }
            }) {
                VStack {
                    Text("开始听写")
                }
            }
            Text("\(recognizedText)")
        }
    }
}

最终实现效果如下：

image.png

通过语音指令，实现程序控制，是不是很爽，赶紧用起来吧。