在实际的APP开发中,我们经常会见到应用的这样的功能 :需要选取手机相册的照片,还有选取视频,拍视频和照相的操作.

在iOS开发中,实现以上的功能就需要用到 UIImagePickerController.

现将 UIImagePickerController的基本用法总结如下 :

#import "ViewController.h"

@interface ViewController ()

//拍照

• (IBAction)takePhoto:(id)sender;

  //拍电影

• (IBAction)takeMovie:(id)sender;

  @property (weak, nonatomic) IBOutlet UIImageView *imgView;

  //选择照片

• (IBAction)selectPhoto:(id)sender;

  //选择视频

• (IBAction)selectVideo:(id)sender;

  @end

  @implementation ViewController

• (void)viewDidLoad {
  [super viewDidLoad];

  //UIImagePickerController.访问用户相册 2.拍照,拍视频

  }

  //1.选取照片

• (IBAction)selectPhoto:(id)sender {

  UIImagePickerController *imagePickerCtrl = [[UIImagePickerController alloc] init];

  /*
  UIImagePickerControllerSourceTypePhotoLibrary,获取相册中所有的文件
  UIImagePickerControllerSourceTypeCamera,摄像头
  UIImagePickerControllerSourceTypeSavedPhotosAlbum,系统内置相册
  */

  //资源类型(资源来自哪里,可以来相册,摄像头)
  imagePickerCtrl.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;

  //设置代理
  imagePickerCtrl.delegate = self;

  //弹出控制器
  [self presentViewController:imagePickerCtrl animated:YES completion:^{

   //弹出控制器完成调用的方法  

  }];

  }
  /**
  *
  * 2.选取视频
  */

• (IBAction)selectVideo:(id)sender {

  UIImagePickerController *imagePickerCtrl = [[UIImagePickerController alloc] init];

  imagePickerCtrl.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
  imagePickerCtrl.delegate = self;

  //指定媒体类型,图片(@"public.image"),视频(@"public.movie")
  imagePickerCtrl.mediaTypes = @[/*@"public.image",*/@"public.movie"];

  [self presentViewController:imagePickerCtrl animated:YES completion:NULL];

  }

  //3.拍照

• (IBAction)takePhoto:(id)sender {

  UIImagePickerController *imagePickerCtrl = [[UIImagePickerController alloc] init];

  imagePickerCtrl.delegate = self;

  //判断手机是否支持(前)摄像头
  if (![UIImagePickerController isCameraDeviceAvailable:UIImagePickerControllerCameraDeviceFront]) {

   UIAlertView \*alerView = \[\[UIAlertView alloc\] initWithTitle:@"提示" message:@"手机太渣,没有摄像头" delegate:nil cancelButtonTitle:@"确定" otherButtonTitles:nil, nil\];  
   \[alerView show\];
  
   return;  

  }

  //指定资源来自摄像头
  imagePickerCtrl.sourceType = UIImagePickerControllerSourceTypeCamera;

  [self presentViewController:imagePickerCtrl animated:YES completion:NULL];

  }

  //4.拍视频

• (IBAction)takeMovie:(id)sender {

  UIImagePickerController *imagePickerCtrl = [[UIImagePickerController alloc] init];

  imagePickerCtrl.delegate = self;

  //指定资源来自摄像头
  imagePickerCtrl.sourceType = UIImagePickerControllerSourceTypeCamera;

  //设置资源类型
  imagePickerCtrl.mediaTypes = @[@"public.movie"];

  [self presentViewController:imagePickerCtrl animated:YES completion:NULL];
  }

  #pragma mark UIImagePickerControllerDelegate
  //选取完视频,或者照片调用的协议方法(不管是拍照,选相册,拍视频,选视频,最终都会调用此方法)

• (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {

  NSLog(@"%@",info);

  //取出选择的照片
  UIImage *img = info[UIImagePickerControllerOriginalImage];

  //将选取的照片交给_imgView显示
  _imgView.image = img;

  //如果资源来自摄像头
  if (picker.sourceType == UIImagePickerControllerSourceTypeCamera) {

   //将图片存到相册中调用的方法  (苹果建议的写法:好像必须要这样写)  
   //- (void)image:(UIImage \*)image didFinishSavingWithError:(NSError \*)error contextInfo:(void \*)contextInfo
  
   **UIImageWriteToSavedPhotosAlbum(img,** self, @selector(image:didFinishSavingWithError:contextInfo:), nil);  

  }

  //如果选中的是视频则可以通过UIImagePickerControllerMediaURL在字典中获取到选中的视频的URL

  //选取照片或视频后,关闭控制器
  [picker dismissViewControllerAnimated:YES completion:NULL];

  }

  //"取消"按钮被点击

• (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {

  NSLog(@"被关闭了");
  [picker dismissViewControllerAnimated:YES completion:NULL];

  }

• (void)image:(UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{

  NSLog(@"照片保存到相册成功");
  }

  @end

这种写法的缺点就是,选取图片的时候只能选取一张照片,如果要选取多张照片的话,就需要用到另外一种方法  AssetsLibrary

AssetsLibrary的基本用法随后更新!!!    记得关注我哟!!!!