IOS打开系统相机的闪光灯

IOS有两种的拍照和视频的方式：

1.直接使用UIImagePickerController，这个类提供了一个简单便捷的拍照与选择图片库里图片的功能。

2.另一种是通过AVFoundation.framework框架完全自定义拍照的界面和选择图片库界面。我只做了第一种，就先给大家介绍第一种做法：

一、首先调用接口前，我们需要先判断当前设备是否支持UIImagePickerController，用isSourceTypeAvailable:来判断是否可用

二、查看符合的媒体类型，这个时候我们调用availableMediaTypeForSourceType：判断

在调用UIImagePickerController时我们需要加入他的两个代理方法：

UINavigationControllerDelegate和UIImagePickerControllerDelegate，在调用摄像头的时候还可以调闪光灯，一会代码里有。

要调用闪光灯需要先建一个AVCaptureSession类的实例对象:

//  Created by 张茫原 on 13-1-23.

//  Copyright (c) 2013年 张茫原. All rights reserved.

//

 

#import <UIKit/UIKit.h>

//调用闪光灯调用框架

#import <AVFoundation/AVFoundation.h>

 

@interface CameraViewController : UIViewController<UINavigationControllerDelegate, UIImagePickerControllerDelegate>

{

    AVCaptureSession * _AVSession;//调用闪光灯的时候创建的类

}

 

@property(nonatomic,retain)AVCaptureSession * AVSession;

 

@end

在.m的- (void)viewDidLoad里建立4Button，Camera调用相机、Library调用图片库、flashlight打开闪光灯、close关闭闪光灯,这里创建Button的代码我就不再写了。

//打开相机

-(void)addCarema

{

    //判断是否可以打开相机，模拟器此功能无法使用

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

         

        UIImagePickerController * picker = [[UIImagePickerController alloc]init];

        picker.delegate = self;

        picker.allowsEditing = YES;  //是否可编辑

        //摄像头

        picker.sourceType = UIImagePickerControllerSourceTypeCamera;

        [self presentModalViewController:picker animated:YES];

        [picker release];

    }else{

        //如果没有提示用户

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"你没有摄像头" delegate:nil cancelButtonTitle:@"Drat!" otherButtonTitles:nil];

        [alert show];

    }

}

打开相机后，然后需要调用UIImagePickerControllerDelegate里的方法，拍摄完成后执行的方法和点击Cancel之后执行的方法：

//拍摄完成后要执行的方法

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info

{

    //得到图片

    UIImage * image = [info objectForKey:UIImagePickerControllerOriginalImage];

    //图片存入相册

    UIImageWriteToSavedPhotosAlbum(image, nil, nil, nil);

    [self dismissModalViewControllerAnimated:YES];

}

//点击Cancel按钮后执行方法

-(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker

{

    [self dismissModalViewControllerAnimated:YES];

}

调用相机照片和保存到图片库已经完成。

接着介绍打开照片库：

-(void)openPicLibrary

{

    //相册是可以用模拟器打开的

    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {

        UIImagePickerController * picker = [[UIImagePickerController alloc]init];

        picker.delegate = self;

        picker.allowsEditing = YES;//是否可以编辑

        //打开相册选择照片

        picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

        [self presentModalViewController:picker  animated:YES];

        [picker release];

    }else{

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"你没有摄像头" delegate:nil cancelButtonTitle:@"Drat!" otherButtonTitles:nil];

        [alert show];

    }

}

//选中图片进入的代理方法

-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(NSDictionary *)editingInfo

{

    [self dismissModalViewControllerAnimated:YES];

}

调用闪光灯的代码，由于我也不是很理解，所以没法加注释，但是已经亲测可用，但是调闪光灯时有一个算是bug吧，闪光灯会闲一下，然后再一直亮

-(void)openFlashlight

{

    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:self.AVSession];

        [output release];

    }

}

-(void)closeFlashlight

{

    [self.AVSession stopRunning];

    [self.AVSession release];

}

以上所述就是本文的全部内容了，希望大家能够喜欢。