iOS|iOS 扫一扫弱光检测 iOS扫一扫弱光检测

如题，处理后摄像头的光感值，确定手电筒显示与隐藏

遵循协议

协议：AVCaptureVideoDataOutputSampleBufferDelegate

添加监听

// 弱光识别监听 AVCaptureVideoDataOutput *buffer = [[AVCaptureVideoDataOutput alloc] init]; [buffer setSampleBufferDelegate:self queue:dispatch_get_main_queue()]; if ([self.session canAddOutput:buffer]) [self.session addOutput:buffer];

AVCaptureVideoDataOutputSampleBufferDelegate 代理

- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {static BOOL isStop = false; if (isStop) return; isStop = true; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{isStop = false; }); CFDictionaryRef metadataDict = CMCopyDictionaryOfAttachments(NULL,sampleBuffer, kCMAttachmentMode_ShouldPropagate); NSDictionary *metadata = https://www.it610.com/article/[[NSMutableDictionary alloc] initWithDictionary:(__bridge NSDictionary*)metadataDict]; CFRelease(metadataDict); NSDictionary *exifMetadata = [[metadata objectForKey:(NSString *)kCGImagePropertyExifDictionary] mutableCopy]; float brightnessValue = [[exifMetadata objectForKey:(NSString *)kCGImagePropertyExifBrightnessValue] floatValue]; UIButton *lightBtn = [self.view viewWithTag:111111]; if (brightnessValue < 0 && !lightBtn.selected && lightBtn.isHidden) {[lightBtn.layer removeAllAnimations]; lightBtn.hidden = false; [lightBtn alphaOrOpacityAnimation]; // 心跳动画 }if (brightnessValue> 0 && !lightBtn.selected && !lightBtn.isHidden) {[lightBtn.layer removeAllAnimations]; lightBtn.hidden = true; } }

心跳动画：UIView的Animation类目

// 呼吸灯动画 - (void)alphaOrOpacityAnimation {CABasicAnimation *animation =[CABasicAnimation animationWithKeyPath:@"opacity"]; animation.fromValue = https://www.it610.com/article/[NSNumber numberWithFloat:1.0f]; animation.toValue = [NSNumber numberWithFloat:0.1f]; // 透明度。 animation.autoreverses = YES; animation.duration = 0.75; animation.repeatCount = 2; animation.removedOnCompletion = NO; animation.fillMode = kCAFillModeForwards; //removedOnCompletion,fillMode配合使用保持动画完成效果 animation.timingFunction=[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn]; [self.layer addAnimation:animation forKey:nil]; }

附上手电筒开关方法代码

//照明按钮点击事件 - (void)lightBtnOnClick:(UIButton *)btn { [btn.layer removeAllAnimations]; // ppExt：不能使用_device：无相机权限不能打开 AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; //判断是否有闪光灯 if (![device hasTorch]) {[self skipToApplicationSettingWith:Error_Torch_Failure IsToSetting:false CancelHanlder:nil]; return; }btn.selected = !btn.selected; [device lockForConfiguration:nil]; if (btn.selected) {[device setTorchMode:AVCaptureTorchModeOn]; }else { [device setTorchMode:AVCaptureTorchModeOff]; } [device unlockForConfiguration]; }