在iOS中要拍照和录制视频最简单的方式就是调用UIImagePickerController，UIImagePickerController继承与UINavigationController，需要使用代理方法时需要同时遵守这两个协议，以前可能比较多的是使用UIImagePickerController来选择相册图片或者拍摄图片，其实它的功能还能用来拍摄视频。
使用UIImagePickerController拍照或者拍视频主要以下几个步骤：
创建一个全局的UIImagePickerController对象。
指定UIImagePickerController的来源sourceType，是来自UIImagePickerControllerSourceTypeCamera相机，还是来自UIImagePickerControllerSourceTypePhotoLibrary相册。
然后是设置mediaTypes媒体类型，这是录制视频必须设置的选项，默认情况下是kUTTypeImage（注意：mediaTypes的设置是在MobileCoreServices框架下），同还可以设置一些其他视频相关的属性，例如：videoQuality视频的质量、videoMaximumDuration视频的最大录制时长（默认为10s），cameraDevice摄像头的方向（默认为后置相机）。
指定相机的捕获模式cameraCaptureMode，设置mediaTypes后在设置捕获模式，注意的是捕获模式需要在相机来源sourceType为相机时设置，否则会出现crash。
适时的展示UIImagePickerController，然后在相应的代理方法保存和获取图片或视频。
下面还是上代码吧，更加清晰明了...
首先需要导入以下用到的几个头文件，同时遵守两个代理方法
#import "ViewController.h"
#import <MobileCoreServices/MobileCoreServices.h>
#import <AVFoundation/AVFoundation.h>
#import <MediaPlayer/MediaPlayer.h>
@interface ViewController ()<UIImagePickerControllerDelegate, UINavigationControllerDelegate>
{
UIImagePickerController *_imagePickerController;
}
创建UIImagePickerController对象
- (void)viewDidLoad {
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib
_imagePickerController = [[UIImagePickerController alloc] init];
_imagePickerController.delegate = self;
_imagePickerController.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
_imagePickerController.allowsEditing = YES;
从摄像头获取图片或视频
#pragma mark 从摄像头获取图片或视频
- (void)selectImageFromCamera
{
_imagePickerController.sourceType = UIImagePickerControllerSourceTypeCamera;
//录制视频时长，默认10s
_imagePickerController.videoMaximumDuration = 15;
//相机类型（拍照、录像...）字符串需要做相应的类型转换
_imagePickerController.mediaTypes = @[(NSString *)kUTTypeMovie,(NSString *)kUTTypeImage];
//视频上传质量
//UIImagePickerControllerQualityTypeHigh高清
//UIImagePickerControllerQualityTypeMedium中等质量
//UIImagePickerControllerQualityTypeLow低质量
//UIImagePickerControllerQualityType640x480
_imagePickerController.videoQuality = UIImagePickerControllerQualityTypeHigh;
//设置摄像头模式（拍照，录制视频）为录像模式
_imagePickerController.cameraCaptureMode = UIImagePickerControllerCameraCaptureModeVideo;
[self presentViewController:_imagePickerController animated:YES completion:nil];
}
从相册获取图片或视频
#pragma mark 从相册获取图片或视频
- (void)selectImageFromAlbum
{
//NSLog(@"相册");
_imagePickerController.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
[self presentViewController:_imagePickerController animated:YES completion:nil];
}
在imagePickerController:didFinishPickingMediaWithInfo:代理方法中处理得到的资源，保存本地并上传...
#pragma mark UIImagePickerControllerDelegate
//该代理方法仅适用于只选取图片时
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingImage:(UIImage *)image editingInfo:(nullable NSDictionary<NSString *,id> *)editingInfo {
NSLog(@"选择完毕----image:%@-----info:%@",image,editingInfo);
}
//适用获取所有媒体资源，只需判断资源类型
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
NSString *mediaType=[info objectForKey:UIImagePickerControllerMediaType];
//判断资源类型
if ([mediaType isEqualToString:(NSString *)kUTTypeImage]){
//如果是图片
self.imageView.image = info[UIImagePickerControllerEditedImage];
//压缩图片
NSData *fileData = UIImageJPEGRepresentation(self.imageView.image, 1.0);
//保存图片至相册
UIImageWriteToSavedPhotosAlbum(self.imageView.image, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
//上传图片
[self uploadImageWithData:fileData];
}else{
//如果是视频
NSURL *url = info[UIImagePickerControllerMediaURL];
//播放视频
_moviePlayer.contentURL = url;
[_moviePlayer play];
//保存视频至相册（异步线程）
NSString *urlStr = [url path];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
if (UIVideoAtPathIsCompatibleWithSavedPhotosAlbum(urlStr)) {
UISaveVideoAtPathToSavedPhotosAlbum(urlStr, self, @selector(video:didFinishSavingWithError:contextInfo:), nil);
}
});
NSData *videoData = [NSData dataWithContentsOfURL:url];
//视频上传
[self uploadVideoWithData:videoData];
}
[self dismissViewControllerAnimated:YES completion:nil];
}
图片和视频保存完毕后的回调
#pragma mark 图片保存完毕的回调
- (void) image: (UIImage *) image didFinishSavingWithError:(NSError *) error contextInfo: (void *)contextInf{
}
#pragma mark 视频保存完毕的回调
- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInf{
if (error) {
NSLog(@"保存视频过程中发生错误，错误信息:%@",error.localizedDescription);
}else{
NSLog(@"视频保存成功.");
}
}
以上仅是简单功能的实现，还有例如切换前后摄像头、闪光灯设置、对焦、曝光模式等更多功能...
