iOS使用UIImagePickerController调用系统相机，相册和图库(2)

要转换CFStringRef和NSString类型，可以使用以下方法:

NSString * str = (__bridge NSString*)kUTTypeMovie;

UIImagePickerController中的更多属性和方法如下:

//设置代理
@property(nullable,nonatomic,weak)      id <UINavigationControllerDelegate, UIImagePickerControllerDelegate> delegate;
//设置书体提供者类型 默认为图库
@property(nonatomic)           UIImagePickerControllerSourceType     sourceType; 
//设置所需要的数据类型，需要设置为系统定义的文件类型字符串数组 默认为kUTTypeImage
@property(nonatomic,copy)      NSArray<NSString *>                   *mediaTypes;
//设置是否允许编辑图片 设置为YES，则用户选择图片时可以编辑裁剪图片
@property(nonatomic)           BOOL                                  allowsEditing;
//设置媒体文件的最大时长 默认为10分钟
@property(nonatomic)           NSTimeInterval                        videoMaximumDuration; 
//设置媒体文件的质量 枚举如下：
/*
typedef NS_ENUM(NSInteger, UIImagePickerControllerQualityType) {
    UIImagePickerControllerQualityTypeHigh = 0,       // 高质量
    UIImagePickerControllerQualityTypeMedium = 1,     // 中等质量
    UIImagePickerControllerQualityTypeLow = 2,         // 低质量
    UIImagePickerControllerQualityType640x480 NS_ENUM_AVAILABLE_IOS(4_0) = 3,    
    UIImagePickerControllerQualityTypeIFrame1280x720 NS_ENUM_AVAILABLE_IOS(5_0) = 4,
    UIImagePickerControllerQualityTypeIFrame960x540 NS_ENUM_AVAILABLE_IOS(5_0) = 5,
} __TVOS_PROHIBITED;
*/
@property(nonatomic)           UIImagePickerControllerQualityType    videoQuality;
//设置是否显示相机控制界面
@property(nonatomic)           BOOL                                  showsCameraControls;
//自定义的拍照界面 其会覆盖在原拍照界面上
@property(nullable, nonatomic,strong) __kindof UIView                *cameraOverlayView  NS_AVAILABLE_IOS(3_1);  
//设置拍照界面的transform
@property(nonatomic)           CGAffineTransform                     cameraViewTransform ;
//拍照
- (void)takePicture NS_AVAILABLE_IOS(3_1);  
//进行视频捕获
- (BOOL)startVideoCapture NS_AVAILABLE_IOS(4_0);
//停止视频捕获
- (void)stopVideoCapture  NS_AVAILABLE_IOS(4_0);
//设置相机捕获模式 照片或视频
@property(nonatomic) UIImagePickerControllerCameraCaptureMode cameraCaptureMode;
//设置相机设备 前置或后置
@property(nonatomic) UIImagePickerControllerCameraDevice      cameraDevice;
//设置闪光灯模式
/*
typedef NS_ENUM(NSInteger, UIImagePickerControllerCameraFlashMode) {
    UIImagePickerControllerCameraFlashModeOff  = -1, //关闭
    UIImagePickerControllerCameraFlashModeAuto = 0,  //自动
    UIImagePickerControllerCameraFlashModeOn   = 1   //开启
} __TVOS_PROHIBITED;
*/
@property(nonatomic) UIImagePickerControllerCameraFlashMode   cameraFlashMode;

//相机拍照完成或者从图库相册选择相片完成后触发的回调方法 editingInfo字典中将传入编辑信息
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(nullable NSDictionary<NSString *,id> *)editingInfo NS_DEPRECATED_IOS(2_0, 3_0);
//相机录像或者从图库相册选择视频完成后触发的回调方法 info字典中是具体信息
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info;
//ImagePickerController取消选择是回调的方法
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;

在上述方法的编辑字典和信息字典中ios调用相机和相册，已经商定了一些键值对. 开发人员可以通过相应的密钥获得所需的信息. 规则如下:

//这个键对应NSString类型的值 意义为媒体文件的格式
UIKIT_EXTERN NSString *const UIImagePickerControllerMediaType;
//这个键对应UIImage类型的值 意义为获取的原始图片
UIKIT_EXTERN NSString *const UIImagePickerControllerOriginalImage;
//这个件对应UIIImage类型的值 意义为获取编辑后的图片
UIKIT_EXTERN NSString *const UIImagePickerControllerEditedImage;
//这个键对应一个NSValue值 可以转为CGRect类型 意义为编辑的图片范围
UIKIT_EXTERN NSString *const UIImagePickerControllerCropRect;
//这个键对应媒体文件的URL
UIKIT_EXTERN NSString *const UIImagePickerControllerMediaURL;
//这个键对应图库中的URL
UIKIT_EXTERN NSString *const UIImagePickerControllerReferenceURL;
//这个键对应一个NSDictionary 里面存放媒体数据
UIKIT_EXTERN NSString *const UIImagePickerControllerMediaMetadata;
//现场图片数据 相机捕捉图片时会记录声音
UIKIT_EXTERN NSString *const UIImagePickerControllerLivePhoto;

系统还提供了一种存储相机照片和视频的方法，如下所示:

//将图片数据存储到相册
void UIImageWriteToSavedPhotosAlbum(UIImage *image, __nullable id completionTarget, __nullable SEL completionSelector, void * __nullable contextInfo);
//将视频保存到相册
BOOL UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(NSString *videoPath);
void UISaveVideoAtPathToSavedPhotosAlbum(NSString *videoPath, __nullable id completionTarget, __nullable SEL completionSelector, void * __nullable contextInfo);

关注技术，热爱生活，交流技术并成为朋友. -珲少

本文来自电脑杂谈，转载请注明本文网址：
http://www.pc-fly.com/a/ruanjian/article-146293-2.html