iOS拍照与摄像代码详解手机开发

sourceType是一个UIImagePickerControllerSourceType类型的枚举值，它表示图像选取控制器的3种不同的媒体来源模式
UIImagePickerControllerSourceTypePhotoLibrary:照片库模式。图像选取控制器以该模式显示时会浏览系统照片库的根目录。
UIImagePickerControllerSourceTypeCamera:相机模式，图像选取控制器以该模式显示时可以进行拍照或摄像。
UIImagePickerControllerSourceTypeSavedPhotosAlbum:相机胶卷模式，图像选取控制器以该模式显示时会浏览相机胶卷目录。
返回的是字符串数组，kUTTypeImage表示静态图片，kUTTypeMovie表示视频。这两个字符串常量定义在MobileCoreServices框架中。
参数info是一个字典，包含媒体类型，拍照的原始图片，编辑后的图片，或是摄像的视频文件的URL等。

// Created by gao wuhang on 12-11-23.

// Copyright (c) 2012年 gao wuhang. All rights reserved.

//

#import

@interface ViewController : UIViewController UINavigationControllerDelegate,UIImagePickerControllerDelegate

(IBAction)takePictureButtonClick:(id)sender;

(IBAction)captureVideoButtonClick:(id)sender;

@end

// Created by gao wuhang on 12-11-23.

// Copyright (c) 2012年 gao wuhang. All rights reserved.

//

#import  ViewController.h

#import

#import

@interface ViewController ()

@end

@implementation ViewController

(IBAction)takePictureButtonClick:(id)sender{

 //检查相机模式是否可用

 if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

 NSLog(@ sorry, no camera or camera is unavailable. );

 return;

 }

 //获得相机模式下支持的媒体类型

 NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];

 BOOL canTakePicture = NO;

 for (NSString* mediaType in availableMediaTypes) {

 if ([mediaType isEqualToString:(NSString*)kUTTypeImage]) {

 //支持拍照

 canTakePicture = YES;

 break;

 }

 }

 //检查是否支持拍照

 if (!canTakePicture) {

 NSLog(@ sorry, taking picture is not supported. );

 return;

 }

 //创建图像选取控制器

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

 //设置图像选取控制器的来源模式为相机模式

 imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;

 //设置图像选取控制器的类型为静态图像

 imagePickerController.mediaTypes = [[[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage, nil]autorelease];

 //允许用户进行编辑

 imagePickerController.allowsEditing = YES;

 //设置委托对象

 imagePickerController.delegate = self;

 //以模视图控制器的形式显示

 [self presentModalViewController:imagePickerController animated:YES];

 [imagePickerController release];

}

(IBAction)captureVideoButtonClick:(id)sender{

 //检查相机模式是否可用

 if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {

 NSLog(@ sorry, no camera or camera is unavailable!!! );

 return;

 }

 //获得相机模式下支持的媒体类型

 NSArray* availableMediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];

 BOOL canTakeVideo = NO;

 for (NSString* mediaType in availableMediaTypes) {

 if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {

 //支持摄像

 canTakeVideo = YES;

 break;

 }

 }

 //检查是否支持摄像

 if (!canTakeVideo) {

 NSLog(@ sorry, capturing video is not supported.!!! );

 return;

 }

 //创建图像选取控制器

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

 //设置图像选取控制器的来源模式为相机模式

 imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;

 //设置图像选取控制器的类型为动态图像

 imagePickerController.mediaTypes = [[[NSArray alloc] initWithObjects:(NSString*)kUTTypeMovie, nil]autorelease];

 //设置摄像图像品质

 imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;

 //设置最长摄像时间

 imagePickerController.videoMaximumDuration = 30;

 //允许用户进行编辑

 imagePickerController.allowsEditing = YES;

 //设置委托对象

 imagePickerController.delegate = self;

 //以模式视图控制器的形式显示

 [self presentModalViewController:imagePickerController animated:YES];

 [imagePickerController release];

 

}

(void)image:(UIImage*)image didFinishSavingWithError:(NSError*)error contextInfo:(void*)contextInfo{

 if (!error) {

 NSLog(@ picture saved with no error. );

 }

 else

 {

 NSLog(@ error occured while saving the picture%@ , error);

 }

}

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

 //打印出字典中的内容

 NSLog(@ get the media info: %@ , info);

 //获取媒体类型

 NSString* mediaType = [info objectForKey:UIImagePickerControllerMediaType];

 //判断是静态图像还是视频

 if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {

 //获取用户编辑之后的图像

 UIImage* editedImage = [info objectForKey:UIImagePickerControllerEditedImage];

 //将该图像保存到媒体库中

 UIImageWriteToSavedPhotosAlbum(editedImage, self,@selector(image:didFinishSavingWithError:contextInfo:), NULL);

 }else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie])

 {

 //获取视频文件的url

 NSURL* mediaURL = [info objectForKey:UIImagePickerControllerMediaURL];

 //创建ALAssetsLibrary对象并将视频保存到媒体库

 ALAssetsLibrary* assetsLibrary = [[ALAssetsLibrary alloc] init];

 [assetsLibrary writeVideoAtPathToSavedPhotosAlbum:mediaURLcompletionBlock:^(NSURL *assetURL, NSError *error) {

 if (!error) {

 NSLog(@ captured video saved with no error. );

 }else

 {

 NSLog(@ error occured while saving the video:%@ , error);

 }

 }];

 [assetsLibrary release];

 }

 [picker dismissModalViewControllerAnimated:YES];

 

}

(void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{

 [picker dismissModalViewControllerAnimated:YES];

}

 

(void)viewDidLoad

{

 [super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

}

(void)viewDidUnload

{

 [super viewDidUnload];

 // Release any retained subviews of the main view.

}

(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation

{

 return (interfaceOrientation != UIInterfaceOrientationPortraitUpsideDown);

}

@end