调用系统相机/相册代码片段

[self showActionSheet:@[@"拍摄/上传",@"从相册中选择照片"] callBackBlock:^(NSString *item) {
           if ([item isEqualToString:@"拍摄/上传"]) {
               [self takePhotoWithCamer];
           }else if ([item isEqualToString:@"从相册中选择照片"]) {
               [self choosePhotoFromLibrary];
           }
       }];

//弹出选项
- (void)showActionSheet:(NSArray *)items callBackBlock:(void(^)(NSString *item))callBackBlock
{
    UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil message:nil preferredStyle:UIAlertControllerStyleActionSheet];
    
    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"取消" style:UIAlertActionStyleCancel handler:nil];
    [alertController addAction:cancelAction];
    
    for (NSString *item in items) {
        UIAlertAction *action = [UIAlertAction actionWithTitle:item style:UIAlertActionStyleDefault handler:^(UIAlertAction * _Nonnull action) {
            if (callBackBlock) {
                callBackBlock(item);
            }
        }];
        [alertController addAction:action];
    }
    [self presentViewController:alertController animated:YES completion:nil];
}

//使用相机拍照
-(void)takePhotoWithCamer{
    if([self isCanUseCamera]){
        UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
        imagePicker.sourceType = UIImagePickerControllerSourceTypeCamera;
        imagePicker.delegate = self;
        imagePicker.allowsEditing = YES;
        imagePicker.showsCameraControls = NO;
        
        UIView * customCameraView = [[UIView alloc] initWithFrame:[UIScreen  mainScreen].bounds];
        UIButton * takePicture = [UIButton buttonWithType:UIButtonTypeCustom];
        takePicture.frame = CGRectMake(0, SGFullScreenHeight-44, SGFullScreenWidth, 44);
        [takePicture setTitle:@"照相" forState:UIControlStateNormal];
        [takePicture sg_handleControlEvent:UIControlEventTouchUpInside withBlock:^(id sender) {
            [imagePicker takePicture];
        }];
        [customCameraView addSubview:takePicture];
        imagePicker.cameraOverlayView = customCameraView;
        
        CGSize screenSize = [[UIScreen mainScreen] bounds].size;
        float aspectRatio = 4.0/3.0;
        float scale = screenSize.height/screenSize.width * aspectRatio;
        imagePicker.cameraViewTransform = CGAffineTransformMakeScale(scale, scale);
        [self presentViewController:imagePicker animated: YES completion: nil];
    }else{
       //@"无法使用相机, 请到 系统设置 -> 隐私 -> 相机 里启动权限"
    }
}


//判断相机是否可用
-(BOOL)isCanUseCamera{
    AVAuthorizationStatus authStatus = [AVCaptureDevice authorizationStatusForMediaType:AVMediaTypeVideo];
    if (authStatus == AVAuthorizationStatusRestricted || authStatus ==AVAuthorizationStatusDenied){
        return NO;
    }else{
        return YES;
    }
}

//从相册选照
-(void)choosePhotoFromLibrary{
    UIImagePickerController *imagePicker = [[UIImagePickerController alloc] init];
    imagePicker.view.tintColor = self.view.tintColor;
    imagePicker.sourceType = UIImagePickerControllerSourceTypeSavedPhotosAlbum;
    imagePicker.allowsEditing = NO;
    imagePicker.delegate = self;
    [self presentViewController:imagePicker animated: true completion: nil];
}

//选照完成
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary<NSString *,id> *)info{
    UIImage *pickedImage = (UIImage *)info[UIImagePickerControllerOriginalImage];
    //...
    [self dismissViewControllerAnimated:YES completion:nil];
    
}

//取消选择
- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker{
    [picker dismissViewControllerAnimated:YES completion:nil];
}