iOS相册、相机(单张图片选取)

UIImagePickerController

(1)代理
<UINavigationControllerDelegate, UIImagePickerControllerDelegate>delegate

(2)几个基本属性设置
sourceType  //设置资源获取类型
allowsEditing   //是否允许图片编辑

(3)几个判断类方法
/**是否可以获取该类型资源*/
+ (BOOL)isSourceTypeAvailable:(UIImagePickerControllerSourceType)sourceType; 

/**是否可以获取该类型相机（前置和后置 ）*/
+ (BOOL)isCameraDeviceAvailable:(UIImagePickerControllerCameraDevice)cameraDevice; 

/**是否可以获取闪光灯*/
+ (BOOL)isFlashAvailableForCameraDevice:(UIImagePickerControllerCameraDevice)cameraDevice;

(4)代理方法（iOS4后仅存2个可用）
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info;
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;
/** 参数info中的键 */
NSString *const  UIImagePickerControllerMediaType ;指定用户选择的媒体类型（文章最后进行扩展）
NSString *const  UIImagePickerControllerOriginalImage ;原始图片
NSString *const  UIImagePickerControllerEditedImage ;修改后的图片
NSString *const  UIImagePickerControllerCropRect ;裁剪尺寸
NSString *const  UIImagePickerControllerMediaURL ;媒体的URL
NSString *const  UIImagePickerControllerReferenceURL ;原件的URL
NSString *const  UIImagePickerControllerMediaMetadata;当来数据来源是照相机的时候这个值才有效

/** UIImagePickerControllerMediaType */
UIImagePickerControllerMediaType 包含着KUTTypeImage 和KUTTypeMovie
KUTTypeImage 包含：
const CFStringRef  kUTTypeImage ;抽象的图片类型
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;

KUTTypeMovie 包含：
const CFStringRef  kUTTypeAudiovisualContent ;抽象的声音视频
const CFStringRef  kUTTypeMovie ;抽象的媒体格式（声音和视频）
const CFStringRef  kUTTypeVideo ;只有视频没有声音
const CFStringRef  kUTTypeAudio ;只有声音没有视频
const CFStringRef  kUTTypeQuickTimeMovie ;
const CFStringRef  kUTTypeMPEG ;
const CFStringRef  kUTTypeMPEG4 ;
const CFStringRef  kUTTypeMP3 ;
const CFStringRef  kUTTypeMPEG4Audio ;
const CFStringRef  kUTTypeAppleProtectedMPEG4Audio;