獲取系統(tǒng)相機(jī)、相冊用法十分簡單，直接上代碼，分分鐘學(xué)會。

在某ViewController中直接調(diào)用如下代碼即可

1.使用前應(yīng)先判斷是否可用
//照相機(jī)是否可用
BOOL isCameraAvailable = [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera];
//相冊是否可用
BOOL isPhotoLibraryAvailable = [UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypePhotoLibrary];

2.初始化UIImagePickerController
UIImagePickerController *picker = [[UIImagePickerController alloc] init];

3.設(shè)置picker的類型（只能設(shè)置一個）
picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;//設(shè)置為此即打開相冊
picker.sourceType = UIImagePickerControllerSourceTypeCamera;//設(shè)置為此即打開相機(jī)

4.設(shè)置回調(diào)代理（用于選中圖片或者拍照完成后回圖片的各種信息）
//注意：此處需要遵循兩個代理協(xié)議
//UIImagePickerControllerDelegate 用于選擇照片或拍照后回調(diào)
//UINavigationControllerDelegate 在相機(jī)/相冊選擇中會有Nav進(jìn)行跳轉(zhuǎn)，此代理可以用于監(jiān)聽事件
<UINavigationControllerDelegate, UIImagePickerControllerDelegate>   
picker.delegate = self;

5.彈出相機(jī)/相冊（一定要使用modal形式才可彈出）
[self presentViewController:picker animated:YES completion:nil];

6.實(shí)現(xiàn)代理監(jiān)聽相機(jī)/相冊回調(diào)
#pragma mark - UIImageViewPickerDelegate 相機(jī)/相冊 回調(diào)
- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info
{
    //選擇完成后dismiss選擇控制器，同時(shí)處理選擇的圖
    [picker dismissViewControllerAnimated:YES completion:^
    {
        //info中有選中圖片的全部信息，根據(jù)需要去獲取，此處獲取的為原圖
        UIImage *choiceImage = [info objectForKey:UIImagePickerControllerOriginalImage];
     
        if (picker.sourceType == UIImagePickerControllerSourceTypeCamera)
        {
            //若為相機(jī)拍攝則保存到相冊
            UIImageWriteToSavedPhotosAlbum(choiceImage, NULL, NULL, NULL);
        }
    }];
}

補(bǔ)充：
1.picker獲取前置攝像頭 （默認(rèn)為后置UIImagePickerControllerCameraDeviceRear）
picker.cameraDevice = UIImagePickerControllerCameraDeviceFront;

2.對選中圖片進(jìn)行編輯
picker.allowsEditing = YES;設(shè)置后選中圖片則可以進(jìn)行區(qū)域編輯

3.以上屬性需要在present之前設(shè)置有效