自我剖析：工作五年多，以项目为驱动，重复工作，缺少钻研精神。

随手记录一些东西，偏向于源码的

day 1 ：ios UIImagePickerController 

UIImagePickerController 继承UINavigationController，可通过init(navigationBarClass:AnyClass?, toolbarClass:AnyClass?)自定义导航栏

open class func isSourceTypeAvailable(_ sourceType: UIImagePickerController.SourceType) -> Bool // returns YES if source is available (i.e. camera present) //判断类型是否有效

    open class func availableMediaTypes(for sourceType: UIImagePickerController.SourceType) -> [String]? // returns array of available media types (i.e. kUTTypeImage)//有效的类型

    @available(iOS 4.0, *)

    open class func isCameraDeviceAvailable(_cameraDevice:UIImagePickerController.CameraDevice) ->Bool// returns YES if camera device is available  //相机是否有效

    @available(iOS 4.0, *)

    open class func isFlashAvailable(for cameraDevice: UIImagePickerController.CameraDevice) -> Bool // returns YES if camera device supports flash and torch. //是否支持flash和torch

    @available(iOS 4.0, *)

    open class func availableCaptureModes(for cameraDevice: UIImagePickerController.CameraDevice) -> [NSNumber]? // returns array of NSNumbers (UIImagePickerControllerCameraCaptureMode) //

    weak open var delegate: (UIImagePickerControllerDelegate & UINavigationControllerDelegate)? //代理写法

    open var sourceType: UIImagePickerController.SourceType // default value is UIImagePickerControllerSourceTypePhotoLibrary.

    open var mediaTypes: [String]

    // default value is an array containing kUTTypeImage.

    @available(iOS 3.1, *)

    open var allowsEditing: Bool // replacement for -allowsImageEditing; default value is NO.

    @available(iOS 11.0, *)

    open var imageExportPreset: UIImagePickerController.ImageURLExportPreset // default value is UIImagePickerControllerImageExportPresetCompatible.

    // video properties apply only if mediaTypes includes kUTTypeMovie

    @available(iOS 3.1, *)

    open var videoMaximumDuration: TimeInterval // default value is 10 minutes.

    @available(iOS 3.1, *)

    open var videoQuality: UIImagePickerController.QualityType // default value is UIImagePickerControllerQualityTypeMedium. If the cameraDevice does not support the videoQuality, it will use the default value.

    @available(iOS 11.0, *)

    open var videoExportPreset: String // videoExportPreset can be used to specify the transcoding quality for videos (via a AVAssetExportPreset* string). If the value is nil (the default) then the transcodeQuality is determined by videoQuality instead. Not valid if the source type is UIImagePickerControllerSourceTypeCamera

    // camera additions available only if sourceType is UIImagePickerControllerSourceTypeCamera.

    @available(iOS 3.1, *)

    open var showsCameraControls: Bool // set to NO to hide all standard camera UI. default is YES

    @available(iOS 3.1, *)

    open var cameraOverlayView: UIView? // set a view to overlay the preview view.

    @available(iOS 3.1, *)

    open var cameraViewTransform: CGAffineTransform // set the transform of the preview view.

    @available(iOS 3.1, *)

    open func takePicture()

    // programatically initiates still image capture. ignored if image capture is in-flight.

    // clients can initiate additional captures after receiving -imagePickerController:didFinishPickingMediaWithInfo: delegate callback

    @available(iOS 4.0, *)

    open func startVideoCapture() ->Bool

    @available(iOS 4.0, *)

    open func stopVideoCapture()

    @available(iOS 4.0, *)

    open var cameraCaptureMode: UIImagePickerController.CameraCaptureMode // default is UIImagePickerControllerCameraCaptureModePhoto

    @available(iOS 4.0, *)

    open var cameraDevice: UIImagePickerController.CameraDevice // default is UIImagePickerControllerCameraDeviceRear

    @available(iOS 4.0, *)

    open var cameraFlashMode: UIImagePickerController.CameraFlashMode // default is UIImagePickerControllerCameraFlashModeAuto. 

enum SourceType :Int{

        case photoLibrary

        case camera

        case savedPhotosAlbum

    }

enum QualityType :Int{

        case typeHigh// highest quality

        case typeMedium // medium quality, suitable for transmission via Wi-Fi 

        case typeLow // lowest quality, suitable for tranmission via cellular network

        @available(iOS4.0, *)

        case type640x480// VGA quality

        @available(iOS5.0, *)

        case typeIFrame1280x720

        @available(iOS5.0, *)

        case typeIFrame960x540

    }

enum CameraCaptureMode :Int{

        case photo

        case video

    }

enum CameraDevice :Int{

        case rear

        case front

    }

enum CameraFlashMode :Int{

        case off

        case auto

        case on

    }

enum ImageURLExportPreset :Int{//@available(iOS 11.0, *)

        case compatible

        case current

    }

public struct InfoKey : Hashable, Equatable, RawRepresentable {

        publicinit(rawValue:String)

    }

UIImagePickerController.InfoKey 

    public static let mediaType: UIImagePickerController.InfoKey

    public static let originalImage: UIImagePickerController.InfoKey // a UIImage

    public static let editedImage: UIImagePickerController.InfoKey // a UIImage

    public static let cropRect: UIImagePickerController.InfoKey // an NSValue (CGRect)

    public static let mediaURL: UIImagePickerController.InfoKey // an NSURL

    @available(iOS, introduced: 4.1, deprecated: 11.0, message: "Replace with public API: UIImagePickerControllerPHAsset")

    public static let referenceURL: UIImagePickerController.InfoKey // an NSURL that references an asset in the AssetsLibrary framework

    @available(iOS 4.1, *)

    public static let mediaMetadata: UIImagePickerController.InfoKey // an NSDictionary containing metadata from a captured photo

    @available(iOS 9.1, *)

    public static let livePhoto: UIImagePickerController.InfoKey // a PHLivePhoto

    @available(iOS 11.0, *)

    public static let phAsset: UIImagePickerController.InfoKey // a PHAsset

    @available(iOS 11.0, *)

    public static let imageURL: UIImagePickerController.InfoKey // an NSURL

public protocol UIImagePickerControllerDelegate :NSObjectProtocol{

    @available(iOS 2.0, *)

    optional public func imagePickerController(_picker:UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey:Any])

    @available(iOS 2.0, *)

    optional public func imagePickerControllerDidCancel(_picker:UIImagePickerController)

}

// Adds a photo to the saved photos album.  The optional completionSelector should have the form:

//  - (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo;

//将照片添加到已保存的相册中,有时会crash。可以尝试下先将image转为png,再存储。而且图片不应过大，过大也会导致崩溃。

public func UIImageWriteToSavedPhotosAlbum(_image:UIImage,_completionTarget:Any?,_completionSelector:Selector?,_contextInfo:UnsafeMutableRawPointer?)

// Is a specific video eligible to be saved to the saved photos album? //视频是否可以保存

@available(iOS 3.1, *)

public func UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(_videoPath:String) ->Bool

// Adds a video to the saved photos album. The optional completionSelector should have the form: 

//  - (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo;//将视频添加到已保存的相册中

@available(iOS 3.1, *)

public func UISaveVideoAtPathToSavedPhotosAlbum(_videoPath:String,_completionTarget:Any?,_completionSelector:Selector?,_contextInfo:UnsafeMutableRawPointer?)

next：PHAsset