iOS中屏幕亮度與閃光燈控制詳解

更新時(shí)間：2017年06月01日 09:58:51 作者：呀咪9527

這篇文章主要給大家介紹了關(guān)于iOS中屏幕亮度與閃光燈控制的相關(guān)資料，文中介紹的非常詳細(xì)，對(duì)大家具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面來(lái)一起看看吧。

本文主要介紹的是關(guān)于iOS屏幕亮度與閃光燈控制的相關(guān)內(nèi)容，分享出來(lái)供大家參考學(xué)習(xí)，下面來(lái)看看詳細(xì)的介紹：

所用涉及框架：AVFoundation框架和ImageIO

讀取屏幕亮度： [UIScreen mainScreen].brightness;

設(shè)置屏幕亮度： [[UIScreen mainScreen] setBrightness:0.5];

獲取環(huán)境亮度主要代碼：

- (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(jù)brightnessValue的值來(lái)打開(kāi)和關(guān)閉閃光燈
 AVCaptureDevice*device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
 BOOL result = [device hasTorch];// 判斷設(shè)備是否有閃光燈
 if((brightnessValue <0) && result) {
 // 打開(kāi)閃光燈
  [device lockForConfiguration:nil];
  [device setTorchMode:AVCaptureTorchModeOn];//開(kāi)
  [device unlockForConfiguration];
 }else if((brightnessValue >0) && result) {
 // 關(guān)閉閃光燈
  [device lockForConfiguration:nil];  
  [device setTorchMode:AVCaptureTorchModeOff];//關(guān)
  [device unlockForConfiguration]; 
 }
}

總結(jié)

以上就是這篇文章的全部?jī)?nèi)容了，希望本文的內(nèi)容對(duì)大家的學(xué)習(xí)或者工作能帶來(lái)一定的幫助，如果有疑問(wèn)大家可以留言交流，謝謝大家對(duì)腳本之家的支持。

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