如何使用AVCaptureFlashMode [英] How do I use AVCaptureFlashMode

问题描述

我在制作一个应用程序，让我将图像拼接成一个全景的场景。我想要能够以编程方式打开iPhone 4上的Flash LED。

我该如何做？

我阅读文档，发现我需要使用AVCaptureFlashMode

但我不知道如何使用它？

$

---

更新的代码如下。谢谢SIF！

 
 NSError * error = nil; 
 NSLog（@设置LED）; 
 
 if（[captDevice hasTorch] == NO）
 {
 NSLog（@错误：此设备没有火炬）; 
} 
 if（[captDevice isTorchModeSupported：AVCaptureTorchModeOn] == NO）
 {
 NSLog（@Error：This device does not support AVCaptureTorchModeOn）; 
} 
 
 AVCaptureSession * captureSession = [[AVCaptureSession alloc] init]; 
 AVCaptureDeviceInput * videoInput = [[AVCaptureDeviceInput alloc] initWithDevice：captDevice错误：&错误]; 
 AVCaptureVideoDataOutput * videoOutput = [[AVCaptureVideoDataOutput allocate] init]; 
 
 if（videoInput && videoOutput）
 {
 [captureSession addInput：videoInput]; 
 [captureSession addOutput：videoOutput]; 
 if（[captDevice lockForConfiguration：&error]）
 {
 if（flag == YES）{
 captDevice.torchMode = AVCaptureTorchModeOn; 
} else {
 captDevice.torchMode = AVCaptureTorchModeOff; 
} 
 [captDevice unlockForConfiguration]; 
} 
 else 
 {
 NSLog（@无法锁定设备的配置错误：％@，错误）; 
} 
 [captureSession startRunning]; 
} 
 else 
 {
 NSLog（@Error：％@，error）; 
} 
 

如何关闭它？

解决方案

  AVCaptureDevice * d = nil; 
 
 //按位置查找设备
 NSArray * allDevices = [AVCaptureDevice devices]; 
 for（AVCaptureDevice * currentDevice in allDevices）{
 if（currentDevice.position == AVCaptureDevicePositionBack）{
 d = currentDevice; 
} 
} 
 
 //此时，d可能仍为nil，假设我们发现了我们喜欢的东西.... 
 
 NSError * err = nil; 
 BOOL lockAcquired = [d lockForConfiguration：& err]; 
 
 if（！lockAcquired）{
 // log err and handle ... 
} else {
 //在闪光模式下翻转
 if （[d hasFlash]&& [d isFlashModeSupported：AVCaptureFlashModeOn]）{
 [d setFlashMode：AVCaptureFlashModeOn]; 
} 
 
 [d unlockForConfiguration]; 
} 
  

I'm making an app to allow me to stitch images together into a panoramic scene. I want to be able to turn the Flash LED on the iPhone 4 programatically.

How can I do this?

I read the documentation and discovered that I need to use AVCaptureFlashMode

but I can't figure out how 2 use it?

any help would be appreciated.

---

Updated Code below. Thanks SIF!

NSError* error = nil;
    NSLog(@"Setting up LED");

    if([captDevice hasTorch] == NO)
    {
        NSLog(@"Error: This device doesnt have a torch");
    }
    if([captDevice isTorchModeSupported:AVCaptureTorchModeOn] == NO)
    {
        NSLog(@"Error: This device doesnt support AVCaptureTorchModeOn");
    }

    AVCaptureSession* captureSession = [[AVCaptureSession alloc] init];
    AVCaptureDeviceInput* videoInput = [[AVCaptureDeviceInput alloc] initWithDevice:captDevice error:&error];
    AVCaptureVideoDataOutput* videoOutput = [[AVCaptureVideoDataOutput alloc] init];

    if (videoInput && videoOutput) 
    {
        [captureSession addInput:videoInput];
        [captureSession addOutput:videoOutput];
        if([captDevice lockForConfiguration:&error])
        {
            if (flag == YES) {
                captDevice.torchMode = AVCaptureTorchModeOn;
            } else {
                captDevice.torchMode = AVCaptureTorchModeOff;
            }           
            [captDevice unlockForConfiguration];
        }
        else 
        {
            NSLog(@"Could not lock device for config error: %@", error);
        }
        [captureSession startRunning];
    }
    else 
    {
        NSLog(@"Error: %@", error);
    }

How do you turn it off?

解决方案

AVCaptureDevice* d = nil;

// find a device by position
NSArray* allDevices = [AVCaptureDevice devices];
for (AVCaptureDevice* currentDevice in allDevices) {
  if (currentDevice.position == AVCaptureDevicePositionBack) {
    d = currentDevice;
  }
}

// at this point, d may still be nil, assuming we found something we like....

NSError* err = nil;
BOOL lockAcquired = [d lockForConfiguration:&err];

if (!lockAcquired) {
   // log err and handle...
} else {
   // flip on the flash mode
   if ([d hasFlash] && [d isFlashModeSupported:AVCaptureFlashModeOn] ) {
      [d setFlashMode:AVCaptureFlashModeOn];
   }

   [d unlockForConfiguration];
}

这篇关于如何使用AVCaptureFlashMode的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！