UIImagePickerController 拍照与摄像

UIImagePickerController拍照与摄像

 

该类继承自UINavigationController类

步骤：

 

检查媒体来源模式是否可用

 

检查该来源模式下所支持的媒体类型

 

创建图像选取控制器，设置其属性并显示

 

在委托协议方法中处理

 

 

 

1.检查媒体来源

 

调用UIImagePickerController类的静态方法isSourceTypeAvailable来检查

 

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。

 

如果设备支持指定的媒体来源模式，则isSourceTypeAvailable:方法返回YES，否则返回NO。

 

2.检查支持的媒体类型

 

调用UIImagePickerController类的另一个静态方法 availableMediaTypesForSourceType:

 

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。

 

//

//  ViewController.h

//  Camera

//

//  Created by gao wuhang on 12-11-23.

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

//

 

#import

 

@interface ViewController : UIViewController<</span>UINavigationControllerDelegate, UIImagePickerControllerDelegate>

 

- (IBAction)takePictureButtonClick:(id)sender;

- (IBAction)captureVideoButtonClick:(id)sender;

 

@end

 

//

//  ViewController.m

//  Camera

//

//  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:mediaURL completionBlock:^(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