实现功能：
相机拍照，把图像保持到系统相册。
运行环境：
1. XCODE 5.1.1
2. 真机（IPHONE5 , IOS6.1.4）
#import <UIKit/UIKit.h>
#import <AVFoundation/AVFoundation.h> //导入 - "视频流"@interface MCViewController : UIViewController
@property (strong, nonatomic) AVCaptureSession * captureSession; //AVCaptureSession实例
@property (strong, nonatomic) AVCaptureDeviceInput * videoInput; //持有视频输入实例@property (strong, nonatomic) AVCaptureStillImageOutput * stillImageOutput; //持有静态图像输出实例
@end
//
// MCViewController.m
// MyCamera#import "MCViewController.h"
@interface MCViewController ()
@end
@implementation MCViewController
#pragma mark - life cycle
- (void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:animated];//开始扑捉会话
[self.captureSession startRunning];
}- (void)viewWillDisappear:(BOOL)animated
{
[super viewWillDisappear:animated];//停止扑捉会话
[self.captureSession stopRunning];
}- (void)viewDidLoad
{
[super viewDidLoad];//初始化视频流
[self initAv];//添加拍照按钮
[self addCaptureButton];
}#pragma mark - 初始化视频流
- (void) initAv
{
//1.1 创建AVCaptureSession
self.captureSession = [[AVCaptureSession alloc] init];
//1.2 指定输入设备。这里使用后摄像头。
AVCaptureDevice * device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];
//1.3 创建AVCaptureDeviceInput的实例，将所选设备作为扑捉会话的输入。
// 此外，在将是其添加到回话前请创建好输入，这里需要做个检查。
NSError * error = nil;
self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:device error:&error];
if (self.videoInput) {
[self.captureSession addInput:self.videoInput];
}
else
{
NSLog(@"input error : %@", error);
}//2. 创建预览层
AVCaptureVideoPreviewLayer * previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];
UIView * aView = self.view;
previewLayer.frame = CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height);
[aView.layer addSublayer:previewLayer];//3. 实现拍照
self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
NSDictionary * stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:AVVideoCodecJPEG,AVVideoCodecKey, nil];
[self.stillImageOutput setOutputSettings:stillImageOutputSettings];
[self.captureSession addOutput:self.stillImageOutput];}
#pragma mark - 添加按钮 AND 点击按钮事件
- (void)addCaptureButton
{
CGRect frame = CGRectMake(0, 0, 100, 100);
UIButton * btn = [UIButton buttonWithType:UIButtonTypeRoundedRect];
btn.frame = frame;
[btn setTitle:@"拍照" forState:UIControlStateNormal];
btn.backgroundColor = [UIColor clearColor];
btn.tag = 1111;
[btn addTarget:self action:@selector(onClickCaptureButton:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:btn];
}-(IBAction)onClickCaptureButton:(id)sender
{
[self takePicture];
}#pragma mark - 保持图像到相册
- (void)saveImageToPhotos:(UIImage*)savedImage
{
UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}// 指定回调方法
- (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo
{
NSString * msg = nil ;
if(error != NULL)
{
msg = @"保存图片失败" ;
}
else
{
msg = @"保存图片成功" ;
}UIAlertView * alert = [[UIAlertView alloc] initWithTitle:@"保存图片结果提示"
message:msg
delegate:self
cancelButtonTitle:@"确定"
otherButtonTitles:nil];
[alert show];
}#pragma mark - 拍照函数
//拍照
- (void) takePicture
{
//1.
AVCaptureConnection * stillImageConnection = [self.stillImageOutput.connections objectAtIndex:0];if ([stillImageConnection isVideoOrientationSupported]) {
[stillImageConnection setVideoOrientation:AVCaptureVideoOrientationPortrait];
}//2.
[self.stillImageOutput captureStillImageAsynchronouslyFromConnection:stillImageConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {if (imageDataSampleBuffer != NULL)
{
//图像数据类型转换
NSData * imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage * image = [[UIImage alloc] initWithData:imageData];//保存图像
[self saveImageToPhotos:image];}
else
{
NSLog(@"Error capturing still image %@", error);
}
}];}
@end
自定义相机（二） -- 拍照