Step of operation:
1. Create a new UMG, select DT User Widget
2. Use the traditional method to build this UMG control.
3. Use the creation window and display
DT User Widget Explanation ：
DT User Widget is inherited in User Widget, has all the functions of User Widget, and adds several new blueprint nodes.
Can cover nodes ：
On Window Activated ：When the window is activated
On Window Deactivated ：When the window loses the activation state
On Window Closed ：When the window is destroyed and closed
Functional node ：
Show Window ：Display window
Hide Window ： Hidden window
Close Window ： The window is closed and destroyed
Global blueprint node description：
Create Window
Window is a platform-agnostic representation of a top-level window.
Class : The type of DT User Widget.
Title : Title of the window.
ClientSize : What the initial size of the window should be.
DoModal : Modal window.
Show : Show window.
WindowType : Type of this window.
ScreenPosition : Screen-space position where the window should be initially located.
AutoCenter : The windows auto-centering mode. If set to anything other than None, then the ScreenPosition value will be ignored.
DragAnywhere : The windows auto-ceWhen true, the window can be dragged from anywhere.
IsInitiallyMaximized : Is the window initially maximized.
IsInitiallyMinimized : Is the window initially minimized.
SizingRule : How the window should be sized.
IsTopmostWindow : True if this window should always be on top of all other windows.
FocusWhenFirstShown : Should this window be focused immediately after it is shown?
HasCloseButton : Does this window have a close button?
SupportsMaximize : Can this window be maximized?
SupportsMinimize : Can this window be minimized?
ShouldPreserveAspectRatio : Should this window preserve its aspect ratio when resized by user?
MinWidth : The smallest width this window can be in Desktop Pixel Units.
MinHeight : The smallest height this window can be in Desktop Pixel Units.
MaxWidth : The biggest width this window can be in Desktop Pixel Units.
MaxHeight : The biggest height this window can be in Desktop Pixel Units.
Close All Window
Close and destroy all the currently created windows
