(1) Effect
(2) Source code download (material replacement)
http://download.csdn.net/detail/wsb200514/8183437
(3) Summary
-All of these can be packaged to develop their category based on UIImage.
--graphical context, with main operations such as opening uigraphicsbeginimagecontextwithoptions, getting uigraphicsgetcurrentcontext and closing Uigraphicsendpdfcontext , there will be a turn off.
--Other pictures and text, is directly with drawinrect painting to the context, only the screenshot is different, the screenshot is essentially a layer of view layers to operate, when used to render renderincontext, which layer to render, who will call this method.
--The main idea in the case is to open a graphical context, then draw or render in this context, and finally get the content in context, that is, the desired image uigraphicsgetimagefromcurrentimagecontext.
"iOS Development-82" Four case study quartz2d: Analog Uiimageview, round head cut, water seal, screenshot