本文主要介紹的是關于iOS屏幕亮度與閃光燈控制的相關內容，分享出來供大家參考學習，下面來看看詳細的介紹：
所用涉及框架：AVFoundation框架和ImageIO
讀取屏幕亮度： [UIScreen mainScreen].brightness;
設置屏幕亮度： [[UIScreen mainScreen] setBrightness:0.5];
獲取環境亮度主要代碼：
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- (void)getTorch { AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; AVCaptureDeviceInput *input = [[AVCaptureDeviceInput alloc]initWithDevice:device error:nil]; AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init]; [output setSampleBufferDelegate:self queue:dispatch_get_main_queue()]; self.session = [[AVCaptureSession alloc]init]; [self.session setSessionPreset:AVCaptureSessionPresetHigh]; if ([self.session canAddInput:input]) { [self.session addInput:input]; } if ([self.session canAddOutput:output]) { [self.session addOutput:output]; } [self.session startRunning];}- (void)captureOutput:(AVCaptureOutput*)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection*)connection { CFDictionaryRef metadataDict =CMCopyDictionaryOfAttachments(NULL,sampleBuffer, kCMAttachmentMode_ShouldPropagate); NSDictionary *metadata = [[NSMutableDictionary alloc] initWithDictionary: (__bridgeNSDictionary*)metadataDict]; CFRelease(metadataDict); NSDictionary *exifMetadata = [[metadata objectForKey:(NSString*)kCGImagePropertyExifDictionary] mutableCopy]; float brightnessValue = [[exifMetadata objectForKey:(NSString*)kCGImagePropertyExifBrightnessValue] floatValue]; NSLog(@"%f",brightnessValue); // 根據brightnessValue的值來打開和關閉閃光燈 AVCaptureDevice*device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; BOOL result = [device hasTorch];// 判斷設備是否有閃光燈 if((brightnessValue <0) && result) { // 打開閃光燈 [device lockForConfiguration:nil]; [device setTorchMode:AVCaptureTorchModeOn];//開 [device unlockForConfiguration]; }else if((brightnessValue >0) && result) { // 關閉閃光燈 [device lockForConfiguration:nil]; [device setTorchMode:AVCaptureTorchModeOff];//關 [device unlockForConfiguration]; }} |
總結
以上就是這篇文章的全部內容了，希望本文的內容對大家的學習或者工作能帶來一定的幫助，如果有疑問大家可以留言交流，謝謝大家對服務器之家的支持。
原文鏈接：http://www.jianshu.com/p/6a134ecc306a
