iOS 從拍照，圖庫，相冊獲取圖片

iOS  獲取圖片有三種方法

1 直接調用攝像頭拍照

2 從相冊中選擇

3 從圖庫中選擇

UIImagePickerController 是系統提供的用來獲取圖片和視頻的接口；

用UIImagePickerController 類來獲取圖片視頻；

大體分為以下幾個步驟：

1. 初始化UIImagePickerController 類
2. 設置UIImagePickerController 實例的數據來源類型（下面解釋）；
3. 設置設置代理
4. 如果需要做圖片修改的話設置allowsEditing =yes

enum {
   UIImagePickerControllerSourceTypePhotoLibrary ,//來自圖庫
   UIImagePickerControllerSourceTypeCamera ,//來自相機
   UIImagePickerControllerSourceTypeSavedPhotosAlbum //來自相冊
};

在用這些來源的時候最好檢測以下設備是否支持；

 if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera])
    {
        NSLog(@"支持相機");
    }
    if([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary])
    {
        NSLog(@"支持圖庫");
    }
    if ([UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeSavedPhotosAlbum])
    {
        NSLog(@"支持相片庫");
    }

- (void)viewDidLoad {
    [super viewDidLoad];
    picker = [[UIImagePickerController alloc]init];
    picker.view.backgroundColor = [UIColor orangeColor];
    UIImagePickerControllerSourceType sourcheType = UIImagePickerControllerSourceTypeCamera;
    picker.sourceType = sourcheType;
    picker.delegate = self;
    picker.allowsEditing = YES;
}

[self presentViewController:picker animated:YES completion:nil];

UIImagePickerControllerDelegate

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

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;

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

選取的信息都在info中

info 是一個字典 

字典中得鍵

NSString *const  UIImagePickerControllerMediaType ;指定用戶選擇的媒體類型（文章最后進行擴展）
NSString *const  UIImagePickerControllerOriginalImage ;原始圖片
NSString *const  UIImagePickerControllerEditedImage ;修改后的圖片
NSString *const  UIImagePickerControllerCropRect ;裁剪尺寸
NSString *const  UIImagePickerControllerMediaURL ;媒體的URL
NSString *const  UIImagePickerControllerReferenceURL ;原件的URL
NSString *const  UIImagePickerControllerMediaMetadata;當來數據來源是照相機的時候這個值才有效

UIImagePickerController 的更多參數參考http://blog.sina.com.cn/s/blog_68edaff101019ppe.html

代理中得功能參考 http://bbs.9ria.com/forum.php?mod=viewthread&tid=244453

UIImagePickerControllerMediaType 包含著KUTTypeImage 和KUTTypeMovie

KUTTypeImage 包含

const CFStringRef  kUTTypeImage ;抽象的圖片類型
const CFStringRef  kUTTypeJPEG ;
const CFStringRef  kUTTypeJPEG2000 ;
const CFStringRef  kUTTypeTIFF ;
const CFStringRef  kUTTypePICT ;
const CFStringRef  kUTTypeGIF ;
const CFStringRef  kUTTypePNG ;
const CFStringRef  kUTTypeQuickTimeImage ;
const CFStringRef  kUTTypeAppleICNS 
const CFStringRef kUTTypeBMP;
const CFStringRef  kUTTypeICO;

const CFStringRef  kUTTypeAudiovisualContent ;抽象的聲音視頻
const CFStringRef  kUTTypeMovie ;抽象的媒體格式（聲音和視頻）
const CFStringRef  kUTTypeVideo ;只有視頻沒有聲音
const CFStringRef  kUTTypeAudio ;只有聲音沒有視頻
const CFStringRef  kUTTypeQuickTimeMovie ;
const CFStringRef  kUTTypeMPEG ;
const CFStringRef  kUTTypeMPEG4 ;
const CFStringRef  kUTTypeMP3 ;
const CFStringRef  kUTTypeMPEG4Audio ;
const CFStringRef  kUTTypeAppleProtectedMPEG4Audio;