编辑.plist文件,添加两个key-value，打开相机和相册的访问权限
1) 申请相机权限：

<key>NSCameraUsageDescription</key>
<string>This app will use camera.</string>

2) 申请相册权限

<key>NSPhotoLibraryUsageDescription</key>
<string>You can select photos to attach to reports.</string>

在xcode中拖一个UIImageview 控件


继承下面两个类

UINavigationControllerDelegate

UIImagePickerControllerDelegate

实现方法：

class yourController:...,UINavigationControllerDelegate,UIImagePickerControllerDelegate  {
...


}

1. 拍照按钮实现：

@IBAction func your_take_photo_action(_ sender: UIButton) {
        imagePicker =  UIImagePickerController()
        imagePicker.delegate = self
        imagePicker.sourceType = .camera
        present(imagePicker,animated: true,completion: nil)
    }

2. 保存相册

@IBAction func save(_ sender: AnyObject) {
        UIImageWriteToSavedPhotosAlbum(imageTake.image!,self,#selector(image(_:didFinishSavingWithError:contextInfo:)),nil)
    }

3. 实现以下两个开启相机和选中图片的回调函数

func image(_ image: UIImage,didFinishSavingWithError error: Error?,contextInfo: UnsafeRawPointer) {
        if let error = error {
            // we got back an error!
            let ac = UIAlertController(title: "Save error",message: error.localizedDescription,preferredStyle: .alert)
            ac.addAction(UIAlertAction(title: "OK",style: .default))
            present(ac,animated: true)
        } else {
            let ac = UIAlertController(title: "Saved!",message: "Your altered image has been saved to your photos.",animated: true)
        }
    }


    //MARK: - Done image capture here
    func imagePickerController(_ picker: UIImagePickerController,didFinishPickingMediaWithInfo info: [String : Any]) {
         imagePicker.dismiss(animated: true,completion: nil)
        imageTake.image = info[UIImagePickerControllerOriginalImage] as? UIImage
    }

最后如果希望转换成base64，可以使用以下函数

func UIImgToBase64(img:UIImage) ->String{
        let imageData:NSData = UIImagePNGRepresentation(img)! as NSData
        let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
        return strBase64
    }