导入UIImagePickerControllerDelegate并创建一个变量来分配UIImagePickerController var imagePicker = UIImagePickerController()和set imagePicker.delegate = self。

创建一个操作表以显示“相机”和“照片库”的选项。

在按钮上单击操作：

@IBAction func buttonOnClick(_ sender: UIButton)
{
    self.btnEdit.setTitleColor(UIColor.white, for: .normal)
    self.btnEdit.isUserInteractionEnabled = true

    let alert = UIAlertController(title: "Choose Image", message: nil, preferredStyle: .actionSheet)
    alert.addAction(UIAlertAction(title: "Camera", style: .default, handler: { _ in
        self.openCamera()
    }))

    alert.addAction(UIAlertAction(title: "Gallery", style: .default, handler: { _ in
        self.openGallary()
    }))

    alert.addAction(UIAlertAction.init(title: "Cancel", style: .cancel, handler: nil))

    /*If you want work actionsheet on ipad
    then you have to use popoverPresentationController to present the actionsheet,
    otherwise app will crash on iPad */
    switch UIDevice.current.userInterfaceIdiom {
    case .pad:
        alert.popoverPresentationController?.sourceView = sender
        alert.popoverPresentationController?.sourceRect = sender.bounds
        alert.popoverPresentationController?.permittedArrowDirections = .up
    default:
        break
    }

    self.present(alert, animated: true, completion: nil)
}

func openCamera()
{
    if(UIImagePickerController .isSourceTypeAvailable(UIImagePickerControllerSourceType.camera))
    {
        imagePicker.sourceType = UIImagePickerControllerSourceType.camera
        imagePicker.allowsEditing = true
        self.present(imagePicker, animated: true, completion: nil)
    }
    else
    {
        let alert  = UIAlertController(title: "Warning", message: "You don't have camera", preferredStyle: .alert)
        alert.addAction(UIAlertAction(title: "OK", style: .default, handler: nil))
        self.present(alert, animated: true, completion: nil)
    }
}

func openGallary()
{
    imagePicker.sourceType = UIImagePickerControllerSourceType.photoLibrary
    imagePicker.allowsEditing = true
    self.present(imagePicker, animated: true, completion: nil)
}

从此处下载示例项目。