远程屏幕抓屏，截取当前屏幕画面，形成一个位图文件，然后把文件发送到控制端电脑并显示-interception current screen images, forming a bitmap documents, then send the file to control and display the computer terminal

添加上线分组, 显示分组主机数量，修改了察看远程屏幕的位图设置-Adding on-line group, group show hosts, modify the look at remote screen bitmap setting