Polygon
Function Description: The Pickup by Polygon function allows users to select a series of vector objects by using a polygon frame.
Steps
1.Click Polygon 
button in the Vector Editor, use the mouse to continuously click multiple points to determine the nodes of the polygon box, double-click the left button of the mouse to select the polygon box and draw it, and the vectors in the box and intersecting with the box will be selected and highlighted. If multiple vectors are selected, a tree-structured dialog box will pop up on the right side of the view, including all currently selected vectors. Clicking the node with the left mouse button will deselect other vectors, and only select the corresponding vector and highlight it.
Polygon selection vector
Polygon frame vector - vector tree
Note: Select the shortcut key to copy, delete and other operations are the same as Pickup Vector.