最近在项目中,使用到相机,然后自己还不是很懂,因为自己接触的项目不是很常用到,但是现在接触的项目要做拍照上传头像功能,然后自己就在各个博客,搬了一些砖,但是还是不太理解,然后有时间自己就多多造一些轮子。 然后先去官网看看,有没有demo,找到了很久以前的一个(传送门)。然后自己就Coding了一遍。
UIImagePickerController 的理解
1. 它是系统统一提供UI的,好像并不能修改它的UI,但是能控制它的显示View,通过cameraOverlayView属性
2.它的使用场景:拍照(不支持Live Photo)、录像、存取图片和video
3.简单使用:
//1. 创建相机对象
imagePicker = [[UIImagePickerController alloc] init];
//2. 设置相机属性
//2.1 来源: 有相机、 图库、相簿
imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
//2.2 媒体类型:⚠️ 最好先设置 mediaTypes, 再设置 cameraCaptureMode,
// kUTTypeImage (拍照,默认)
// kUTTypeVideo(视频,但不带声音)
// kUTTypeMovie(视频并带有声音)
// kUTTypeLivePhoto (取得 Live Photo) > iOS 9
imagePicker.mediaTypes = [UIImagePickerController availableMediaTypesForSourceType:UIImagePickerControllerSourceTypeCamera];//[NSArray arrayWithObjects:(NSString *)kUTTypeImage, (NSString *)kUTTypeMovie, nil];
//2.3 相机类型:录像或拍照
imagePicker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo;
imagePicker.allowsEditing = NO;// 允许图片编辑,拍照后可以简单的编辑图片
imagePicker.showsCameraControls = YES;
imagePicker.cameraViewTransform = CGAffineTransformIdentity;
//2.4 设置摄像头 :设置之前一定要先判断device 是否有后摄像头,不是每个device 都有前后摄像头的
if ([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear]) {
imagePicker.cameraDevice = UIImagePickerControllerCameraDeviceRear;
if ([UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {
cameraSelectionButton.alpha = 1.0;
showCameraSelection = YES;
}
} else{
imagePicker.cameraDevice = UIImagePickerControllerCameraDeviceFront;
}
//2.5 设置闪光灯 :设置之前一定要先判断device 是否支持
if ([UIImagePickerController isFlashAvailableForCameraDevice:imagePicker.cameraDevice]) {
imagePicker.cameraFlashMode = UIImagePickerControllerCameraFlashModeOff;
flashModeButton.alpha = 1.0;
showFlashMode = YES;
}
imagePicker.videoMaximumDuration = 10;//10s 它默认最大录像时间是 10 minute = 600s
//iOS 11 之后使用 videoExportPreset
if (@available(iOS 11.0, *)) {
imagePicker.videoExportPreset = AVAssetExportPreset1280x720;
} else {
// iOS 11 之前
imagePicker.videoQuality = UIImagePickerControllerQualityType640x480;
}
// 代理
imagePicker.delegate = self;
//3. 显示
[self presentViewController:imagePicker animated:YES completion:nil];
代理方法
不管是拍照录像,还是取照片都会走代理方法,存直接调用C语言方法
//前面两个只会调用一个☝️,两个都实现只会调用第二个
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(nullable NSDictionary<NSString *,id> *)editingInfo NS_DEPRECATED_IOS(2_0, 3_0);
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info;
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker;
去照片时,如果调用的是第二个方法,可以通过字典和相关的key,取得对应的图片或video。例如: UIImagePickerControllerOriginalImage
存图片和video 就比较简单,直接调用C语言函数:
//存图片,传path,和回调事件(判断是否存取成功),不传也行
// 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;//回调方法格式
UIKIT_EXTERN void UIImageWriteToSavedPhotosAlbum(UIImage *image, __nullable id completionTarget, __nullable SEL completionSelector, void * __nullable contextInfo) __TVOS_PROHIBITED;
//以下都是存video的,只是最后的方法,有回调事件(判断是否存取成功)
// Is a specific video eligible to be saved to the saved photos album?
UIKIT_EXTERN BOOL UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(NSString *videoPath) NS_AVAILABLE_IOS(3_1) __TVOS_PROHIBITED;
// 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;//回调方法格式
UIKIT_EXTERN void UISaveVideoAtPathToSavedPhotosAlbum(NSString *videoPath, __nullable id completionTarget, __nullable SEL completionSelector, void * __nullable contextInfo) NS_AVAILABLE_IOS(3_1) __TVOS_PROHIBITED;
这个东西比较简单。API 也比较简单。
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