我知道打开闪光灯并在iPhone 4上保持打开的唯一方法是打开相机。我不太确定代码。这是我正在尝试的:
-(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;
}
}
有人知道这是否有效还是我遗漏了什么? (我还没有iPhone 4进行测试 - 只是尝试了一些新的API)。
由于
答案 0 :(得分:70)
这是一个较短的版本,您现在可以使用它打开或关闭灯光:
AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
if ([device hasTorch]) {
[device lockForConfiguration:nil];
[device setTorchMode:AVCaptureTorchModeOn]; // use AVCaptureTorchModeOff to turn off
[device unlockForConfiguration];
}
更新:( 2015年3月)
使用iOS 6.0及更高版本,您可以使用以下方法控制割炬的亮度或级别:
- (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];
}
}
您可能还希望监控来自success
的返回值(setTorchModeOnWithLevel:
)。如果您尝试将水平设置得太高并且割炬过热,则可能会出现故障。在这种情况下,将水平设置为AVCaptureMaxAvailableTorchLevel
会将水平设置为给定火炬温度时允许的最高水平。
答案 1 :(得分:36)
iWasRobbed的答案很棒,除了 AVCaptureSession 一直在后台运行。根据Instrument的说法,在我的iPhone 4s上需要大约12%的CPU功率,因此我的应用程序在一分钟内耗费了大约1%的电量。换句话说,如果设备准备用于AV捕获,它并不便宜。
使用我的应用程序下面的代码每分钟需要0.187%,因此电池续航时间超过5倍。
此代码适用于任何设备(在3GS(无闪存)和4s上测试)。在模拟器中也测试了4.3。
#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];
}
}
}
答案 2 :(得分:18)
请在下方查看更好的答案: https://stackoverflow.com/a/10054088/308315
旧回答:
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
然后在你的AppDelegate .m文件中:
@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;
}
然后,只要你想打开它,就做这样的事情:
// 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];
}
类似的关闭它:
// 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];
}
答案 3 :(得分:15)
您的代码中设置了lockforConfiguration
,您声明AVCaptureDevice
属性。
[videoCaptureDevice lockForConfiguration:nil];
答案 4 :(得分:2)
//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];
}
答案 5 :(得分:2)
从iOS 6.0及更高版本开启/关闭手电筒闪光灯,
- (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];
}
}
P.S。如果您没有开/关功能,则此方法仅可建议。请记住,还有一个选项Auto
。即AVCaptureFlashModeAuto
和AVCaptureTorchModeAuto
。为了支持自动模式,您还可以跟踪当前模式并根据闪光灯和闪光灯的变化模式进行操作。炬。
答案 6 :(得分:2)
Swift 2.0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
}
}
}
答案 7 :(得分:1)
这项工作非常好......希望对某人有所帮助!
-(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];
}
}
}