打開iPhone上的手電筒/閃光燈

我知道開啓閃光燈並將其保持在iPhone 4上的唯一方法是打開攝像機。雖然我不太確定代碼。這是我正在嘗試：打開iPhone上的手電筒/閃光燈

-(IBAction)turnTorchOn { 
    AVCaptureSession *captureSession = [[AVCaptureSession alloc] init]; 
    AVCaptureDevice *videoCaptureDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
    NSError *error = nil; 
    AVCaptureDeviceInput *videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoCaptureDevice error:&error]; 

    if (videoInput) { 
     [captureSession addInput:videoInput]; 

     AVCaptureVideoDataOutput* videoOutput = [[AVCaptureVideoDataOutput alloc] init]; 
     [videoOutput setSampleBufferDelegate:self queue:dispatch_get_current_queue()]; 

     [captureSession addOutput:videoOutput]; 

     [captureSession startRunning]; 

     videoCaptureDevice.torchMode = AVCaptureTorchModeOn; 
    } 
}

有誰知道這是否會工作，或者我錯過了什麼？（我還沒有測試iPhone 4，只是嘗試一些新的API）。

感謝

來源

2010-07-06 John

的lockforConfiguration在你的代碼，你宣佈你的AVCaptureDevice是一個屬性設置。

[videoCaptureDevice lockForConfiguration:nil];

來源

2010-07-09 07:31:49

見下一個更好的答案：https://stackoverflow.com/a/10054088/308315

老答案：

首先，在你的AppDelegate .h文件中：

#import <AVFoundation/AVFoundation.h> 

@interface AppDelegate : NSObject <UIApplicationDelegate> { 

    AVCaptureSession *torchSession; 

} 

@property (nonatomic, retain) AVCaptureSession * torchSession; 

@end

然後在你的AppDe使節.m文件：

@implementation AppDelegate 

@synthesize torchSession; 

- (void)dealloc { 
    [torchSession release]; 

    [super dealloc]; 
} 

- (id) init { 
    if ((self = [super init])) { 

    // initialize flashlight 
    // test if this class even exists to ensure flashlight is turned on ONLY for iOS 4 and above 
     Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice"); 
     if (captureDeviceClass != nil) { 

      AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 

      if ([device hasTorch] && [device hasFlash]){ 

       if (device.torchMode == AVCaptureTorchModeOff) { 

       NSLog(@"Setting up flashlight for later use..."); 

        AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil]; 
        AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init]; 

        AVCaptureSession *session = [[AVCaptureSession alloc] init]; 

       [session beginConfiguration]; 
        [device lockForConfiguration:nil]; 

        [session addInput:flashInput]; 
        [session addOutput:output]; 

        [device unlockForConfiguration]; 

        [output release]; 

       [session commitConfiguration]; 
       [session startRunning]; 

       [self setTorchSession:session]; 
       [session release]; 
        } 

      } 

     } 
    } 
    return self; 
}

那麼任何時候你想打開它，只是做這樣的事情：

// test if this class even exists to ensure flashlight is turned on ONLY for iOS 4 and above 
Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice"); 
if (captureDeviceClass != nil) { 

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 

    [device lockForConfiguration:nil]; 

    [device setTorchMode:AVCaptureTorchModeOn]; 
    [device setFlashMode:AVCaptureFlashModeOn]; 

    [device unlockForConfiguration]; 

}

而對於關閉它類似：

// test if this class even exists to ensure flashlight is turned on ONLY for iOS 4 and above 
Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice"); 
if (captureDeviceClass != nil) { 

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 

    [device lockForConfiguration:nil]; 

    [device setTorchMode:AVCaptureTorchModeOff]; 
    [device setFlashMode:AVCaptureFlashModeOff]; 

    [device unlockForConfiguration]; 
}

來源

2010-07-29 22:19:08 iwasrobbed

在appdelegate.m文件，您應該將'init'法的東西，如內容：'如果（（自我= [超級的init]）） {...}返回自我;' – Senseful 2011-04-28 06:05:48

這太combursom，並保持會話消耗電池。從Tibidabo試試下面的方法 – doozMen 2013-02-27 15:42:47

這裏有一個現在可以使用較短的版本打開或關閉燈光：

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
if ([device hasTorch]) { 
    [device lockForConfiguration:nil]; 
    [device setTorchMode:AVCaptureTorchModeOn]; // use AVCaptureTorchModeOff to turn off 
    [device unlockForConfiguration]; 
}

UPDATE：（2015年3月）

與iOS 6.0和更高版本，可以使用下面的方法控制火炬的亮度或級別：

- (void)setTorchToLevel:(float)torchLevel 
{ 
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
    if ([device hasTorch]) { 
     [device lockForConfiguration:nil]; 
     if (torchLevel <= 0.0) { 
      [device setTorchMode:AVCaptureTorchModeOff]; 
     } 
     else { 
      if (torchLevel >= 1.0) 
       torchLevel = AVCaptureMaxAvailableTorchLevel; 
      BOOL success = [device setTorchModeOnWithLevel:torchLevel error:nil]; 
     } 
     [device unlockForConfiguration]; 
    } 
}

您可能還需要監視的返回值（ success）從setTorchModeOnWithLevel:。如果您嘗試將電平設置得太高而手電筒過熱，則可能會失敗。在這種情況下，將等級設置爲AVCaptureMaxAvailableTorchLevel會將等級設置爲考慮到割炬溫度所允許的最高等級。

來源

2011-11-01 09:48:50 mahboudz

這使我在嘗試切換閃光燈時確實使事情變得更簡單和更有反應。我曾經使用過iWasRobbed發佈的方法，但它並沒有很好的響應。 – 2012-01-02 02:50:42

美女！發揮了魅力。 – 2012-03-17 04:51:55

iWasRobbed的回答很好，除了有一個AVCaptureSession一直在後臺運行。在我的iPhone 4s上，根據儀器需要大約12％的CPU電量，所以我的應用程序在一分鐘內耗電約1％。換句話說，如果設備準備進行AV捕捉，那麼它並不便宜。

使用下面的代碼我的應用程序每分鐘需要0.187％的電量，所以電池的使用壽命要長5倍以上。

此代碼適用於任何設備（在3GS（無閃存）和4s上都測試過）。在模擬器中測試4.3也是如此。

#import <AVFoundation/AVFoundation.h> 

- (void) turnTorchOn:(BOOL)on { 

    Class captureDeviceClass = NSClassFromString(@"AVCaptureDevice"); 
    if (captureDeviceClass != nil) { 
     AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
     if ([device hasTorch] && [device hasFlash]){ 

      [device lockForConfiguration:nil]; 
      if (on) { 
       [device setTorchMode:AVCaptureTorchModeOn]; 
       [device setFlashMode:AVCaptureFlashModeOn]; 
       torchIsOn = YES; 
      } else { 
       [device setTorchMode:AVCaptureTorchModeOff]; 
       [device setFlashMode:AVCaptureFlashModeOff]; 
       torchIsOn = NO;    
      } 
      [device unlockForConfiguration]; 
     } 
    } 
}

來源

2012-04-07 11:33:27 Tibidabo

此版本適用於哪些版本的ios？ – Mona 2012-04-08 10:05:31

它應該可以工作，即它應該從5.0開始工作，並且它不應該低於此值。 – Tibidabo 2012-04-08 14:28:05

謝謝，它肯定適用於5.0和5.1，我很擔心4.3 – Mona 2012-04-10 09:11:20

//import fremework in .h file 

#import <AVFoundation/AVFoundation.h> 
{ 
AVCaptureSession *torchSession; 
} 

@property(nonatomic,retain)AVCaptureSession *torchSession; 


-(IBAction)onoff:(id)sender; 

//implement in .m file 

@synthesize torchSession; 

-(IBAction)onoff:(id)sender 
{ 
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
    if ([device hasTorch] && [device hasFlash]) 
    { 
     if (device.torchMode == AVCaptureTorchModeOff) 
     { 
      [button setTitle:@"OFF" forState:UIControlStateNormal]; 

      AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil]; 

      AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init]; 
      AVCaptureSession *session = [[AVCaptureSession alloc] init]; 

      [session beginConfiguration]; 
      [device lockForConfiguration:nil]; 
      [device setTorchMode:AVCaptureTorchModeOn]; 
      [device setFlashMode:AVCaptureFlashModeOn]; 
      [session addInput:flashInput]; 
      [session addOutput:output]; 
      [device unlockForConfiguration]; 
      [output release]; 
      [session commitConfiguration]; 
      [session startRunning]; 
      [self setTorchSession:session]; 
      [session release]; 
     } 
     else 
     { 
      [button setTitle:@"ON" forState:UIControlStateNormal]; 
      [torchSession stopRunning]; 
     } 
    } 
} 

- (void)dealloc 
{ 
    [torchSession release]; 
    [super dealloc]; 
}

來源

2012-08-28 09:55:56 Rushabh

我寫了一個火炬插件，用於科爾多瓦2.2.0適用。你可以在這裏找到它：

來源

2013-01-24 16:40:08

從的iOS 6.0及以上版本，在切換火炬閃光燈開/關，

- (void) toggleFlash { 
    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 
    if ([device hasTorch] && [device hasFlash]){ 
     [device lockForConfiguration:nil]; 
     [device setFlashMode:(device.flashActive) ? AVCaptureFlashModeOff : AVCaptureFlashModeOn]; 
     [device setTorchMode:(device.torchActive) ? AVCaptureTorchModeOff : AVCaptureTorchModeOn]; 
     [device unlockForConfiguration]; 
    } 
}

附：如果您沒有開/關功能，這種方法只能被暗示。請記住還有一個選項Auto。即AVCaptureFlashModeAuto和AVCaptureTorchModeAuto。爲了支持自動模式，您還可以跟蹤當前模式並根據閃光燈的變化模式。

來源

2014-11-25 06:20:50 Hemang

這項工作很好..希望它可以幫助某人！

-(IBAction)flashlight:(id)sender { 

    AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]; 

    if ([device hasTorch] && [device hasFlash]){ 

     if (device.torchMode == AVCaptureTorchModeOff) { 

      [sender setTitle:@"Torch Off" forState:UIControlStateNormal]; 

      AVCaptureDeviceInput *flashInput = [AVCaptureDeviceInput deviceInputWithDevice:device error: nil]; 
      AVCaptureVideoDataOutput *output = [[AVCaptureVideoDataOutput alloc] init]; 

      AVCaptureSession *cam = [[AVCaptureSession alloc] init]; 

      [cam beginConfiguration]; 
      [device lockForConfiguration:nil]; 

      [device setTorchMode:AVCaptureTorchModeOn]; 
      [device setFlashMode:AVCaptureFlashModeOn]; 

      [cam addInput:flashInput]; 
      [cam addOutput:output]; 

      [device unlockForConfiguration]; 

      [cam commitConfiguration]; 
      [cam startRunning]; 

      [self setTorchSession:cam]; 
     } 
     else { 
      [sender setTitle:@"Torch On" forState:UIControlStateNormal]; 
      [_torchSession stopRunning]; 
     } 
    } 
}

來源

2015-08-21 12:21:10 Jonas

雨燕2.0的版本：

func setTorchLevel(torchLevel: Float) 
{ 
    self.captureSession?.beginConfiguration() 
    defer { 
     self.captureSession?.commitConfiguration() 
    } 

    if let device = backCamera?.device where device.hasTorch && device.torchAvailable { 
     do { 
      try device.lockForConfiguration() 
      defer { 
       device.unlockForConfiguration() 
      } 

      if torchLevel <= 0.0 { 
       device.torchMode = .Off 
      } 
      else if torchLevel >= 1.0 { 
       try device.setTorchModeOnWithLevel(min(torchLevel, AVCaptureMaxAvailableTorchLevel)) 
      } 
     } 
     catch let error { 
      print("Failed to set up torch level with error \(error)") 
      return 
     } 
    } 
}

來源

2015-08-30 22:25:14 Avt

打開iPhone上的手電筒/閃光燈

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