原文地址：
前言：近期研究了一下语音识别，从百度语音识别到讯飞语音识别；首先说一下个人针对两者的看法，讯飞毫无疑问比較专业。识别率也非常高真对语音识别是比較精准的，可是非常多开发人员和我一样期望离线识别，而讯飞离线是收费的；请求次数来讲。两者都能够申请高配额，针对用户较多的差点儿都一样。
基于免费而且支持离线我选择了百度离线语音识别。比較简单，UI设计多一点，以下写一下教程：
1.首先：须要的库
2.我是自己定义的UI所以以功能实现为主（头文件）
// 头文件#import "BDVRCustomRecognitonViewController.h"#import "BDVRClientUIManager.h"#import "WBVoiceRecordHUD.h"#import "BDVRViewController.h"#import "MyViewController.h"#import "BDVRSConfig.h"
3.须要知道的功能：能用到的例如以下：
//－－－－－－－－－－－－－－－－－－－类方法－－－－－－－－－－－－－－－－－－－－－－－－// 创建语音识别客户对像，该对像是个单例+ (BDVoiceRecognitionClient *)sharedInstance;// 释放语音识别客户端对像+ (void)releaseInstance;//－－－－－－－－－－－－－－－－－－－识别方法－－－－－－－－－－－－－－－－－－－－－－－// 推断能否够录音- (BOOL)isCanRecorder;// 開始语音识别，须要实现MVoiceRecognitionClientDelegate代理方法。并传入实现对像监听事件// 返回值參考 TVoiceRecognitionStartWorkResult- (int)startVoiceRecognition:(id4.录音button相关动画（我自己定义的，大家能够借鉴）)aDelegate;// 说完了，用户主动完毕录音时调用- (void)speakFinish;// 结束本次语音识别- (void)stopVoiceRecognition;/** * @brief 获取当前识别的採样率 * * @return 採样率(16000/8000) */- (int)getCurrentSampleRate;/** * @brief 得到当前识别模式(deprecated) * * @return 当前识别模式 */- (int)getCurrentVoiceRecognitionMode __attribute__((deprecated));/** * @brief 设置当前识别模式(deprecated)。请使用-(void)setProperty:(TBDVoiceRecognitionProperty)property; * * @param 识别模式 * * @return 是否设置成功 */- (void)setCurrentVoiceRecognitionMode:(int)aMode __attribute__((deprecated));// 设置识别类型- (void)setProperty:(TBDVoiceRecognitionProperty)property __attribute__((deprecated));// 获取当前识别类型- (int)getRecognitionProperty __attribute__((deprecated));// 设置识别类型列表, 除EVoiceRecognitionPropertyInput和EVoiceRecognitionPropertySong外// 能够识别类型复合- (void)setPropertyList: (NSArray*)prop_list;// cityID仅对EVoiceRecognitionPropertyMap识别类型有效- (void)setCityID: (NSInteger)cityID;// 获取当前识别类型列表- (NSArray*)getRecognitionPropertyList;//－－－－－－－－－－－－－－－－－－－提示音－－－－－－－－－－－－－－－－－－－－－－－// 播放提示音。默觉得播放,录音開始，录音结束提示音// BDVoiceRecognitionClientResources/Tone// record_start.caf 录音開始声音文件// record_end.caf 录音结束声音文件// 声音资源须要加到项目project里。用户可替换资源文件，文件名称不能够变，建音提示音不宜过长，0。5秒左右。// aTone 取值參考 TVoiceRecognitionPlayTones，如没有找到文件。则返回ＮＯ- (BOOL)setPlayTone:(int)aTone isPlay:(BOOL)aIsPlay;
// 录音button相关@property (nonatomic, weak, readonly) UIButton *holdDownButton;// 说话button/** * 是否取消錄音 */@property (nonatomic, assign, readwrite) BOOL isCancelled;/** * 是否正在錄音 */@property (nonatomic, assign, readwrite) BOOL isRecording;/** * 当录音button被按下所触发的事件，这时候是開始录音 */- (void)holdDownButtonTouchDown;/** * 当手指在录音button范围之外离开屏幕所触发的事件。这时候是取消录音 */- (void)holdDownButtonTouchUpOutside;/** * 当手指在录音button范围之内离开屏幕所触发的事件，这时候是完毕录音 */- (void)holdDownButtonTouchUpInside;/** * 当手指滑动到录音button的范围之外所触发的事件 */- (void)holdDownDragOutside;5.初始化系统UI
#pragma mark - layout subViews UI/** * 依据正常显示和高亮状态创建一个button对象 * * @param image 正常显示图 * @param hlImage 高亮显示图 * * @return 返回button对象 */- (UIButton *)createButtonWithImage:(UIImage *)image HLImage:(UIImage *)hlImage ;- (void)holdDownDragInside;- (void)createInitView; // 创建初始化界面。播放提示音时会用到- (void)createRecordView; // 创建录音界面- (void)createRecognitionView; // 创建识别界面- (void)createErrorViewWithErrorType:(int)aStatus; // 在识别view中显示具体错误信息- (void)createRunLogWithStatus:(int)aStatus; // 在状态view中显示具体状态信息- (void)finishRecord:(id)sender; // 用户点击完毕动作- (void)cancel:(id)sender; // 用户点击取消动作- (void)startVoiceLevelMeterTimer;- (void)freeVoiceLevelMeterTimerTimer;6.最重要的部分
// 录音完毕 [[BDVoiceRecognitionClient sharedInstance] speakFinish];
// 取消录音[[BDVoiceRecognitionClient sharedInstance] stopVoiceRecognition];7.两个代理方法
- (void)VoiceRecognitionClientWorkStatus:(int)aStatus obj:(id)aObj{ switch (aStatus) { case EVoiceRecognitionClientWorkStatusFlushData: // 连续上屏中间结果 { NSString *text = [aObj objectAtIndex:0]; if ([text length] > 0) {// [clientSampleViewController logOutToContinusManualResut:text]; UILabel *clientWorkStatusFlushLabel = [[UILabel alloc]initWithFrame:CGRectMake(kScreenWidth/2 - 100,64,200,60)]; clientWorkStatusFlushLabel.text = text; clientWorkStatusFlushLabel.textAlignment = NSTextAlignmentCenter; clientWorkStatusFlushLabel.font = [UIFont systemFontOfSize:18.0f]; clientWorkStatusFlushLabel.numberOfLines = 0; clientWorkStatusFlushLabel.backgroundColor = [UIColor whiteColor]; [self.view addSubview:clientWorkStatusFlushLabel]; } break; } case EVoiceRecognitionClientWorkStatusFinish: // 识别正常完毕并获得结果 { [self createRunLogWithStatus:aStatus]; if ([[BDVoiceRecognitionClient sharedInstance] getRecognitionProperty] != EVoiceRecognitionPropertyInput) { // 搜索模式下的结果为数组，演示样例为 // ["公园", "公元"] NSMutableArray *audioResultData = (NSMutableArray *)aObj; NSMutableString *tmpString = [[NSMutableString alloc] initWithString:@""]; for (int i=0; i < [audioResultData count]; i++) { [tmpString appendFormat:@"%@\r\n",[audioResultData objectAtIndex:i]]; } clientSampleViewController.resultView.text = nil; [clientSampleViewController logOutToManualResut:tmpString]; } else { NSString *tmpString = [[BDVRSConfig sharedInstance] composeInputModeResult:aObj]; [clientSampleViewController logOutToContinusManualResut:tmpString]; } if (self.view.superview) { [self.view removeFromSuperview]; } break; } case EVoiceRecognitionClientWorkStatusReceiveData: { // 此状态仅仅有在输入模式下使用 // 输入模式下的结果为带置信度的结果，示比例如以下： // [ // [ // { // "百度" = "0.6055192947387695"; // }, // { // "摆渡" = "0.3625582158565521"; // }, // ] // [ // { // "一下" = "0.7665404081344604"; // } // ], // ]//临时关掉 -- 否则影响跳转结果// NSString *tmpString = [[BDVRSConfig sharedInstance] composeInputModeResult:aObj];// [clientSampleViewController logOutToContinusManualResut:tmpString]; break; } case EVoiceRecognitionClientWorkStatusEnd: // 用户说话完毕，等待server返回识别结果 { [self createRunLogWithStatus:aStatus]; if ([BDVRSConfig sharedInstance].voiceLevelMeter) { [self freeVoiceLevelMeterTimerTimer]; } [self createRecognitionView]; break; } case EVoiceRecognitionClientWorkStatusCancel: { if ([BDVRSConfig sharedInstance].voiceLevelMeter) { [self freeVoiceLevelMeterTimerTimer]; } [self createRunLogWithStatus:aStatus]; if (self.view.superview) { [self.view removeFromSuperview]; } break; } case EVoiceRecognitionClientWorkStatusStartWorkIng: // 识别库開始识别工作，用户能够说话 { if ([BDVRSConfig sharedInstance].playStartMusicSwitch) // 假设播放了提示音。此时再给用户提示能够说话 { [self createRecordView]; } if ([BDVRSConfig sharedInstance].voiceLevelMeter) // 开启语音音量监听 { [self startVoiceLevelMeterTimer]; } [self createRunLogWithStatus:aStatus]; break; } case EVoiceRecognitionClientWorkStatusNone: case EVoiceRecognitionClientWorkPlayStartTone: case EVoiceRecognitionClientWorkPlayStartToneFinish: case EVoiceRecognitionClientWorkStatusStart: case EVoiceRecognitionClientWorkPlayEndToneFinish: case EVoiceRecognitionClientWorkPlayEndTone: { [self createRunLogWithStatus:aStatus]; break; } case EVoiceRecognitionClientWorkStatusNewRecordData: { break; } default: { [self createRunLogWithStatus:aStatus]; if ([BDVRSConfig sharedInstance].voiceLevelMeter) { [self freeVoiceLevelMeterTimerTimer]; } if (self.view.superview) { [self.view removeFromSuperview]; } break; } }} - (void)VoiceRecognitionClientNetWorkStatus:(int) aStatus{ switch (aStatus) { case EVoiceRecognitionClientNetWorkStatusStart: { [self createRunLogWithStatus:aStatus]; [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:YES]; break; } case EVoiceRecognitionClientNetWorkStatusEnd: { [self createRunLogWithStatus:aStatus]; [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO]; break; } }} 8.录音button的一些操作 #pragma mark ------ 关于button操作的一些事情-------- (void)holdDownButtonTouchDown { // 開始动画 _disPlayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(delayAnimation)]; _disPlayLink.frameInterval = 40; [_disPlayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode]; self.isCancelled = NO; self.isRecording = NO; // 開始语音识别功能，之前必须实现MVoiceRecognitionClientDelegate协议中的VoiceRecognitionClientWorkStatus:obj方法 int startStatus = -1; startStatus = [[BDVoiceRecognitionClient sharedInstance] startVoiceRecognition:self]; if (startStatus != EVoiceRecognitionStartWorking) // 创建失败则报告错误 { NSString *statusString = [NSString stringWithFormat:@"%d",startStatus]; [self performSelector:@selector(firstStartError:) withObject:statusString afterDelay:0.3]; // 延迟0.3秒。以便能在出错时正常删除view return; } // "按住说话－松开搜索"提示 [voiceImageStr removeFromSuperview]; voiceImageStr = [[UIImageView alloc]initWithFrame:CGRectMake(kScreenWidth/2 - 40, kScreenHeight - 153, 80, 33)]; voiceImageStr.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:@"searchVoice"]]; [self.view addSubview:voiceImageStr]; }- (void)holdDownButtonTouchUpOutside { // 结束动画 [self.view.layer removeAllAnimations]; [_disPlayLink invalidate]; _disPlayLink = nil; // 取消录音 [[BDVoiceRecognitionClient sharedInstance] stopVoiceRecognition]; if (self.view.superview) { [self.view removeFromSuperview]; }}- (void)holdDownButtonTouchUpInside { // 结束动画 [self.view.layer removeAllAnimations]; [_disPlayLink invalidate]; _disPlayLink = nil; [[BDVoiceRecognitionClient sharedInstance] speakFinish];}- (void)holdDownDragOutside { //假设已經開始錄音了, 才须要做拖曳出去的動作, 否則仅仅要切換 isCancelled, 不讓錄音開始. if (self.isRecording) {// if ([self.delegate respondsToSelector:@selector(didDragOutsideAction)]) {// [self.delegate didDragOutsideAction];// } } else { self.isCancelled = YES; }}#pragma mark - layout subViews UI- (UIButton *)createButtonWithImage:(UIImage *)image HLImage:(UIImage *)hlImage { UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(kScreenWidth/2 -36, kScreenHeight - 120, 72, 72)]; if (image) [button setBackgroundImage:image forState:UIControlStateNormal]; if (hlImage) [button setBackgroundImage:hlImage forState:UIControlStateHighlighted]; return button;}#pragma mark ----------- 动画部分 ------------ (void)startAnimation{ CALayer *layer = [[CALayer alloc] init]; layer.cornerRadius = [UIScreen mainScreen].bounds.size.width/2; layer.frame = CGRectMake(0, 0, layer.cornerRadius * 2, layer.cornerRadius * 2); layer.position = CGPointMake([UIScreen mainScreen].bounds.size.width/2,[UIScreen mainScreen].bounds.size.height - 84); // self.view.layer.position; UIColor *color = [UIColor colorWithRed:arc4random()%10*0.1 green:arc4random()%10*0.1 blue:arc4random()%10*0.1 alpha:1]; layer.backgroundColor = color.CGColor; [self.view.layer addSublayer:layer]; CAMediaTimingFunction *defaultCurve = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionDefault]; _animaTionGroup = [CAAnimationGroup animation]; _animaTionGroup.delegate = self; _animaTionGroup.duration = 2; _animaTionGroup.removedOnCompletion = YES; _animaTionGroup.timingFunction = defaultCurve; CABasicAnimation *scaleAnimation = [CABasicAnimation animationWithKeyPath:@"transform.scale.xy"]; scaleAnimation.fromValue = @0.0; scaleAnimation.toValue = @1.0; scaleAnimation.duration = 2; CAKeyframeAnimation *opencityAnimation = [CAKeyframeAnimation animationWithKeyPath:@"opacity"]; opencityAnimation.duration = 2; opencityAnimation.values = @[@0.8,@0.4,@0]; opencityAnimation.keyTimes = @[@0,@0.5,@1]; opencityAnimation.removedOnCompletion = YES; NSArray *animations = @[scaleAnimation,opencityAnimation]; _animaTionGroup.animations = animations; [layer addAnimation:_animaTionGroup forKey:nil]; [self performSelector:@selector(removeLayer:) withObject:layer afterDelay:1.5];}- (void)removeLayer:(CALayer *)layer{ [layer removeFromSuperlayer];}- (void)delayAnimation{ [self startAnimation];} 完毕以上操作，就大功告成了！ 温馨提示：
1.因为是语音识别，须要用到麦克风相关权限。模拟器会爆12个错误。使用真机能够解决；
2.涉及到授权文件相关并不复杂，projectBundle Identifier仅仅须要设置百度的离线授权一致就可以。例如以下图：
终于效果例如以下：
有不懂或不明确的地方能够微博联系我：
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