Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
210 views
in Technique[技术] by (71.8m points)

c# - How to manually get instance of Graphics object in WinForms?

I know how to work with object of type Graphics (at least I am able to render images) but I always do that by passing graphics object retrieved from OnPaint method.

I would like to display an image when the app is opened (ie in Form_Load method) but have no clue how to obtain the instance of Graphics object I could use? Thanks

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Using the e.Graphics object that OnPaint() supplies to you is the correct way of doing it. It will run right after the OnLoad() method. The form isn't visible yet in OnLoad.

Getting a Graphics object from Control.CreateGraphics() is supported. However, whatever you draw with this will be wiped out as soon as the form repaints itself. Which happens when the user moves another window across yours (pre-Aero) or when she minimizes and restores or otherwise resizes the window. Use CreateGraphics only ever when animating at a high rate.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...