IOS 点滴 2

  再来一篇,嘿嘿

1.sin函数

http://www.iphonedevsdk.com/forum/iphone-sdk-development/34638-how-to-get-sincos-tan-values-correctly.html

直到前两天才知道sin()传参穿的是radian,而不是degree,囧...

2.计算scrollview的滚动速度

http://stackoverflow.com/questions/3719753/iphone-uiscrollview-speed-check

网易新闻全文阅读模式就是算的滚动速度,来控制bar的显示和消失,懒得自己算就copy即可^^

3.NSDate显示错误问题

http://stackoverflow.com/questions/4547379/nsdate-is-not-returning-my-local-time-zone-default-time-zone-of-device

有个回复说的不错:

NSDate is a "raw" date. That's why it is in GMT. It's up to the code to use NSDateFormatter (as you have done) to output the date to a value that makes sense for the user.

http://justcoding.iteye.com/blog/1468089  时间处理,比较全,备忘

4.core image相关,没研究过,先mark

http://www.raywenderlich.com/5689/beginning-core-image-in-ios-5 大神的帖子

http://maniacdev.com/2011/11/tutorial-easy-face-detection-with-core-image-in-ios-5/

http://www.cocoachina.com/iphonedev/sdk/2011/1115/3503.html

两个sample,不错

http://blog.csdn.net/linzhiji/article/details/6742008  对比说的不错

http://hi.baidu.com/yunhuaikong/item/c173c7dc1aab7354d73aae29  

5.图像处理算法

http://www.ruanyifeng.com/blog/2011/08/amazing_algorithms_of_image_processing.html  长见识^^