invalidate

Recently in a Golang little lit up, to clean up the source material The analysis results are based onAudroid API 26 requestLayout()SOURCE Analysis If there is a button on a page, click on the button on the one view.requestLayout() ,

When you use the invalidate (TRUE) function, it adds the WM_ERASEBKGND and WM_PAINT two messages to the message queue.When you use the invalidate (FALSE) function, it only adds a WM_PAINT message to the message queue.The role of the WM_ERASEBKGND

By citation: Invalidate adds an WM_PAINT message to the message queue with an invalid zone for the entire client area. UpdateWindow sends a WM_PAINT message directly, and its invalid extents are the invalid extents of WM_PAINT messages (up to one)

When you do Windows Forms development, you will inevitably need to manually refresh the window to redraw the controls that you want to change, or something else. When this type of demand arises, you have three choices, using the Invalidate,update or

View programming (2): invalidate () in the blog, I talked about the loading time of the ondraw () method of the view and the role of the invalidate () method. In fact, it is far less simple than you think. To write this blog, let's talk about it

Android. invalidate (), android. invalidate Invalidate () invalidates the entire widget and causes the re-painting Control (inherited from the Control .) Invalidate (Region) invalidates the specified area of the control (add it to the update area

Reference: Source   Invalidate () is a member of System. Windows. Forms. Form. It marks the client window area as invalid. Therefore, it ensures that a Paint event is triggered when you need to redraw the window. Invalidate () has two overload

A: When will the message redraw the window occur?The application sends a WM_PAINT message when it is necessary to update or redraw the appearance of the window. Redraws the window.Two: Invalidate ()---RedrawWindow ()--UpdateWindow () What are the

Invalidate adds a wm_paint message to the message queue, and its invalid zone is the entire customer zone. Updatewindow directly sends a wm_paint message. Its invalid zone range is the invalid zone of the wm_paint message in the Message Queue (up

Control. Refresh-does an control. invalidate followed by control. Update.Refresh: forces the control to invalidate its Workspace and immediately redraws itself and any child control. = Invalidate + update Control. invalidate-invalidates a specific

C # advanced programming: invalidate () method Author: anonymous nameArticleSource: http://www.51shuji.com/Release Date: Invalidate ()YesSystem. Windows. Forms. FormIt marks the client window area as invalid, so it can ensure

Control.refresh-does an control.invalidate followed by Control.update.Refresh: Forces the control to invalidate its work area and immediately redraws itself and any child controls. = = Invalidate UpdateControl.invalidate-invalidates a specific

Android notes: differences between invalidate () and postInvalidate () and their usage Android provides the Invalidate method to refresh the interface, but Invalidate cannot be called directly in the thread, because it violates the single-thread

Control. invalidate method: invalidates a specific area of the Control and sends a draw message to the control. Normally, when invalidate () is used to make the region invalid, the re-painting of the control can be triggered, but the re-painting is

There are two sets of methods for implementing view updates in Android, one for invalidate and the other for Postinvalidate, which is used in the UI thread itself and the latter in non-UI threads. Android provides a invalidate method for interface

 1. Why invalidate () cannot be called directly in the thread?2. How does it violate single thread?3. Why is the Android UI not thread-safe?4. Why do Android UI actions have to be performed in the UI thread?1. Why invalidate () cannot be called

In the second part of the wtl clock program, when the timer throws the wm_timer message, the processor ontimer does the following work: Lresult ontimer (uint_ptr nidevent) { if (1! = Nidevent) setmsghandled (false); else { getlocaltime (&

Differences between Invalidate and postInvalidate in android, androidinvalidateIn Android, there are two sets of methods to update the view. One is invalidate, and the other is postInvalidate. The former is in the UI line.And the latter is used in

Control. invalidate Method Invalidates a specific area of the Control and sends a draw message to the control.Reload list Invalidates a specific area of the Control and sends a draw message to the control. Supported by the. NET Framework Lite

Invalidate and updateallviewsThe ondraw () function is executed whenever a window is repainted. It is similar to the message processing function onpaint. When onpaint () is added to the View class, onpaint () overwrites ondraw (). Void invalidate