易语言专用源码，使用API在内存中读取图形数据的句柄-Easy language-specific source, use the API to read graphics data in memory handle

易语言读取DWG预览图源码，易语言写的图形图象编程，很好的参考。-Easy language to read the DWG preview map source, easy graphics programming language to write, a good reference.