Halcon打开多个窗口，指定窗口显示指定内容

* Halcon打开多个窗口，指定窗口显示指定内容
* dev_set_window (WindowHandle1)，先设置指定窗口句柄即可

代码如下：

dev_open_window (0, 0, 300, 300, 'black', WindowHandle1)
dev_open_window (0, 320, 300, 300, 'black', WindowHandle2)dev_open_file_dialog ('read_image', 'default', 'default', Selection)
read_image (Image1, Selection)dev_open_file_dialog ('read_image', 'default', 'default', Selection)
read_image (Image2, Selection)gen_rectangle1 (Rectangle, 3000, 3000, 3100, 3200)
gen_circle (Circle, 3000, 3000, 100.5)dev_set_window (WindowHandle1)
dev_display (Image1)
dev_display (Circle)dev_set_window (WindowHandle2)
dev_display (Image2)
dev_display (Circle)
dev_display (Rectangle)