1.利用UIImagePickeController可以從系統(tǒng)自帶的App(照片,相冊)中獲取圖片
2.設置代理,準守代理協(xié)議
*****注:UIImagePickerController類比較特殊,需要準守兩個代理協(xié)議;

@interface ViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate>  

3.實現(xiàn)代理的方法

#pragma mark  
#pragma mark - imagePicker的 代理方法  
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info  

<span style="color:#333333;">- (IBAction)photo:(id)sender </span><pre name="code" class="objc">{  
    // 1.判斷相冊是否可以打開  
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary]) return;  
    // 2. 創(chuàng)建圖片選擇控制器  
    UIImagePickerController *ipc = [[UIImagePickerController alloc] init];  
    /** 
     typedef NS_ENUM(NSInteger, UIImagePickerControllerSourceType) { 
     UIImagePickerControllerSourceTypePhotoLibrary, // 相冊 
     UIImagePickerControllerSourceTypeCamera, // 用相機拍攝獲取 
     UIImagePickerControllerSourceTypeSavedPhotosAlbum // 相簿 
     } 
     */  
    // 3. 設置打開照片相冊類型(顯示所有相簿)    
    ipc.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;  
    // ipc.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;  
    // 照相機  
    // ipc.sourceType = UIImagePickerControllerSourceTypeCamera;  
    // 4.設置代理  
    ipc.delegate = self;  
    // 5.modal出這個控制器  
    [self presentViewController:ipc animated:YES completion:nil];  
}  

<span style="color:#333333;"></span><pre name="code" class="objc">#pragma mark -- <UIImagePickerControllerDelegate>--  
// 獲取圖片后的操作  
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info  
{  
    // 銷毀控制器  
    [picker dismissViewControllerAnimated:YES completion:nil];  
  
    // 設置圖片  
    self.imageView.image = info[UIImagePickerControllerOriginalImage];  
}