前言
使用UIImagePickerController来实现在项目中添加视频和图片的功能。
属性和方法
| 属性 | 说明 |
|---|---|
| sourceType | 拾取源类型，sourceType是枚举类型：UIImagePickerControllerSourceTypePhotoLibrary：照片库，默认值UIImagePickerControllerSourceTypeCamera：摄像头UIImagePickerControllerSourceTypeSavedPhotosAlbum：相簿 |
| mediaTypes | 媒体类型,默认情况下此数组包含kUTTypeImage，所以拍照时可以不用设置；但是当要录像的时候必须设置，可以设置为kUTTypeVideo（视频，但不带声音）或者kUTTypeMovie（视频并带有声音） |
| videoMaximumDuration | 视频最大录制时长，默认为10 s |
| videoQuality | 视频质量，枚举类型：UIImagePickerControllerQualityTypeHigh：高清质量UIImagePickerControllerQualityTypeMedium：中等质量，适合WiFi传输UIImagePickerControllerQualityTypeLow：低质量，适合蜂窝网传输UIImagePickerControllerQualityType640x480：UIImagePickerControllerQualityTypeIFrame1280x720：UIImagePickerControllerQualityTypeIFrame960x540：960*540 |
| showsCameraControls | 是否显示摄像头控制面板，默认为YES |
| cameraOverlayView | 摄像头上覆盖的视图，可用通过这个视频来自定义拍照或录像界面 |
| cameraViewTransform | 摄像头形变 |
| cameraCaptureMode | 摄像头捕获模式，捕获模式是枚举类型：UIImagePickerControllerCameraCaptureModePhoto：拍照模式UIImagePickerControllerCameraCaptureModeVideo：视频录制模式 |
| cameraDevice | 摄像头设备，cameraDevice是枚举类型：UIImagePickerControllerCameraDeviceRear：前置摄像头UIImagePickerControllerCameraDeviceFront：后置摄像头 |
| cameraFlashMode | 闪光灯模式，枚举类型：UIImagePickerControllerCameraFlashModeOff：关闭闪光灯UIImagePickerControllerCameraFlashModeAuto：闪光灯自动UIImagePickerControllerCameraFlashModeOn：打开闪光灯 |
2.方法####
+ (BOOL)isSourceTypeAvailable:(UIImagePickerControllerSourceType)sourceType
指定的源类型是否可用，sourceType是枚举类型：
UIImagePickerControllerSourceTypePhotoLibrary：照片库
UIImagePickerControllerSourceTypeCamera：摄像头
UIImagePickerControllerSourceTypeSavedPhotosAlbum：相簿
+ (NSArray *)availableMediaTypesForSourceType:(UIImagePickerControllerSourceType)sourceType
指定的源设备上可用的媒体类型，一般就是图片和视频
+ (BOOL)isSourceTypeAvailable:(UIImagePickerControllerSourceType)sourceType;
指定来源是否支持：
UIImagePickerControllerSourceTypePhotoLibrary：来自图库
UIImagePickerControllerSourceTypeCamera：来自相机
UIImagePickerControllerSourceTypeSavedPhotosAlbum：来自相册
+ (BOOL)isCameraDeviceAvailable:(UIImagePickerControllerCameraDevice)cameraDevice
指定的摄像头是否可用，cameraDevice是枚举类型：
UIImagePickerControllerCameraDeviceRear：前置摄像头
UIImagePickerControllerCameraDeviceFront：后置摄像头
+ (BOOL)isFlashAvailableForCameraDevice:(UIImagePickerControllerCameraDevice)cameraDevice
指定摄像头的闪光灯是否可用
+ (NSArray *)availableCaptureModesForCameraDevice:(UIImagePickerControllerCameraDevice)cameraDevice
获得指定摄像头上的可用捕获模式，捕获模式是枚举类型：
UIImagePickerControllerCameraCaptureModePhoto：拍照模式
UIImagePickerControllerCameraCaptureModeVideo：视频录制模式
3.代理和补充
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
代理 - 拍摄或录制完成 这里获取图片或视频信息
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
代理 - 用户取消拍摄
UIImageWriteToSavedPhotosAlbum(UIImage *image, id completionTarget, SEL completionSelector, void *contextInfo)
保存图片到本地�相册
UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(NSString *videoPath)
能否将视频保存到相簿 更安全的判断
void UISaveVideoAtPathToSavedPhotosAlbum(NSString *videoPath, id completionTarget, SEL completionSelector, void *contextInfo)
保存视频到本地�相册
要导入：#import 。不然后出现错误使用未声明的标识符 'kUTTypeImage'
UIImagePickerController的使用流程
- info表中添加权限！！！ 相册
NSPhotoLibraryUsageDescription相机NSCameraUsageDescription麦克风NSMicrophoneUsageDescription- 判断设备是否可用
- 创建UIImagePickerController
- 设置对象属性
- 展示UIImagePickerController窗口 (模态)
- 在代理中处理视频或图片信息 (先save到本地)
此处应有代码
从相册获取图片
/**
相册获取图片
*/
- (BOOL)openPhotoLibrary
{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
return NO;
}
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
picker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage,nil];
picker.allowsEditing = YES; // 允许简单编辑图片
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
return YES;
}
从相册获取视频
/**
相册获取视频
*/
- (BOOL)openVideoLibrary
{
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) {
return NO;
}
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
picker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeMovie,nil];
picker.videoQuality = UIImagePickerControllerQualityTypeMedium;
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
return YES;
}
使用相机拍照
/**
拍照
*/
- (BOOL)openCameraForPhoto
{
// 一般情况下用这个判断
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
// 该设备不支持拍照
return NO;
}
// if (![UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceRear]) {
// // 前置摄像头不可用
// }
// if (![UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {
// // 后置摄像头不可用
// }
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeImage,nil];
picker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModePhoto; //相机的模式 拍照/摄像
picker.allowsEditing = YES; // 允许简单编辑图片
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
return YES;
}
使用相机录像
/**
录制
*/
- (BOOL)openCameraForVideo
{
// 一般情况下用这个判断
if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
// 该设备不支持拍照
return NO;
}
UIImagePickerController *picker = [[UIImagePickerController alloc] init];
picker.sourceType = UIImagePickerControllerSourceTypeCamera;
picker.mediaTypes = [[NSArray alloc] initWithObjects:(NSString*)kUTTypeMovie,nil];
picker.videoMaximumDuration = 10.f; // 视频的最大录制时长
picker.videoQuality = UIImagePickerControllerQualityTypeMedium;
picker.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo; //相机的模式 拍照/摄像
picker.delegate = self;
[self presentViewController:picker animated:YES completion:nil];
return YES;
}
UIImagePickerController代理 获取到媒体资源
/**
UIImagePickerController代理 获取到媒体资源
*/
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
NSString *mediaType = info[UIImagePickerControllerMediaType];
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]) {
// 图片处理
UIImage *image = nil;
if ([picker allowsEditing]) {
image = info[UIImagePickerControllerEditedImage];//获取编辑后的照片
}else {
image = info[UIImagePickerControllerOriginalImage];//获取原始照片
}
if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
UIImageWriteToSavedPhotosAlbum(image, self, @selector(photoPath:didFinishSaveWithError:contextINfo:), nil);//保存到相簿
}
self.photoImageView.image = image;
}else if ([mediaType isEqualToString:(NSString *)kUTTypeMovie]) {
// 视频处理
NSURL *videoUrl = info[UIImagePickerControllerMediaURL];//视频路径
UIImage *image = [self get_videoThumbImage:videoUrl];
self.videoImageView.image = image;
if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {
if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum([videoUrl path])) {
UISaveVideoAtPathToSavedPhotosAlbum([videoUrl path], self, @selector(video:didFinishSavingWithError:contextInfo:), nil);//保存视频到相簿
}
}
}
// 选择图片后手动销毁界面
[picker dismissViewControllerAnimated:YES completion:nil];
}
//图片保存到相册之后的回调
- (void)photoPath:(NSString *)path didFinishSaveWithError:(NSError *)error contextINfo:(void *)contextInfo
{
if (error) {
// 保存失败
}else {
// 处理图片
}
}
//视频保存到相册之后的回调
- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo
{
if (error) {
// 保存失败
}else {
// 处理视频
}
}
UIImagePickerController代理 用户取消操作
/**
用户取消操作
*/
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker
{
// 手动销毁界面
[picker dismissViewControllerAnimated:YES completion:nil];
}
一些有关视频的实用方法
/**
获取视频时长
*/
- (CGFloat)get_videoTotalWith:(NSURL *)videoURL
{
NSDictionary *opts = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:NO]
forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:videoURL options:opts];
float second = 0;
second = urlAsset.duration.value/urlAsset.duration.timescale;
return second;
}
/**
获取视频缩略图
*/
- (UIImage *)get_videoThumbImage:(NSURL *)videoURL
{
NSDictionary *opts = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:NO] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
AVURLAsset *urlAsset = [AVURLAsset URLAssetWithURL:videoURL options:opts];
AVAssetImageGenerator *generator = [AVAssetImageGenerator assetImageGeneratorWithAsset:urlAsset];
generator.appliesPreferredTrackTransform = YES;
CMTime actualTime;
NSError *error = nil;
CGImageRef img = [generator copyCGImageAtTime:CMTimeMake(0, 600) actualTime:&actualTime error:&error];
if (error) {
return nil;
}
return [UIImage imageWithCGImage:img];
}
待补充...
惯例鸣谢 - 参考文献
感谢崔大大的博客:iOS开发系列--音频播放、录音、视频播放、拍照、视频录制
感谢张大大的博客:AVFoundation Programming Guide(官方文档翻译)完整版中英对照