调用iphone4闪光灯

iPhone4加入了闪光灯，下面就分享一下调用闪光灯的方法：

要加入框架：

#import <AVFoundation/AVFoundation.h>

头文件：

#import "AVCaptureDevice.h"

- (void)loadView 

{

[self setView:[[[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]]autorelease]];

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

 

// If torch supported, add button to toggle flashlight on/off

if ([device hasTorch] == YES)

{

flashlightButton = [[UIButton alloc] initWithFrame:CGRectMake(0, 120, 320, 98)];

[flashlightButton setBackgroundImage:[UIImage imageNamed:@"TorchOn.png"]forState:UIControlStateNormal];

[flashlightButton addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];      

[[self view] addSubview:flashlightButton];

}

}

- (void)buttonPressed:(UIButton *)button

{  

if (button == flashlightButton)

{

if (flashlightOn == NO)

{

flashlightOn = YES;

[flashlightButton setBackgroundImage:[UIImage imageNamed:@"TorchOff.png"] forState:UIControlStateNormal];

}

else 

{    

flashlightOn = NO;

[flashlightButton setBackgroundImage:[UIImage imageNamed:@"TorchOn.png"]forState:UIControlStateNormal];

}

[self toggleFlashlight];    

}

}

- (void)toggleFlashlight

{

AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];

 

if (device.torchMode == AVCaptureTorchModeOff) 

{

// Create an AV session

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

 

// Create device input and add to current session

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

[session addInput:input];

 

// Create video output and add to current session      

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

[session addOutput:output];

 

// Start session configuration

[session beginConfiguration];

[device lockForConfiguration:nil];

 

// Set torch to on

[device setTorchMode:AVCaptureTorchModeOn];

 

[device unlockForConfiguration];

[session commitConfiguration];

 

// Start the session

[session startRunning];

 

// Keep the session around

[self setAVSession:session];

 

[output release];

}

else 

{

[AVSession stopRunning];

[AVSession release], AVSession = nil;

}

}