说明：  利用dspack实现拍照功能，dspack控件自行下载。我不太喜欢安装太多控件，但又想能简单的调用控件功能。因此把这个控件封装成容易使用的单元。个人测试觉得dspack操控摄像头功能还是比较大。这个单元实现了获取多个摄像头，以及每个摄像头支持的分辨率和拍照功能，没有弄视频录制功能。
(The function of taking pictures is realized by DSPack, and DSPack controls are downloaded by themselves. I don't like to install too many controls, but I want to be able to simply call control functions. So encapsulate the control as an easy-to-use unit. Personal test found that DSPack control camera function is still relatively large. This unit realizes the acquisition of multiple cameras, as well as the resolution and photographing function supported by each camera, without video recording function.)