在Java或者Javascript的开发中，我们会碰到垃圾回收（Garbage Collection，GC），它和iOS中的自动引用计数（Auto Reference Count，ARC）有什么区别呢？

Contents:

• Description
• KVC
• KVO
• Remove Observers

Description

In Cocoa, the Model-View-Controller pattern, a controller’s responsibility is to keep the view and the model synchronized. There are two parts to this: when the model object changes, the views have to be updated to reflect this change, and when the user interacts with controls, the model has to be updated accordingly.

Key-Value Observing helps us update the views to reflect changes to model objects. The controller can observe changes to those property values that the views depend on.

For more details, refer Key-Value Coding and Observing from objc.io;

Refer Mac和iOS开发资源汇总

Another good github page for iOS resources: iOS 学习资料整理.

其中，最近（2015年）仍然在更新的中文博客：

Refer here

Three units of measurements to size the text in html files to discuss:

1. px
2. em
3. rem

TODO

reference

Description

In Android project, we sometimes want to rend a page in WebView, and need communication between webview and native android side.

Note: Go to here for a project as a sample.

Javascript and Java Bridge

All the attributes of a property defines how the compiler generate the getter and setter accessors.

• atomic / nonatomic
• strong / weak: used for ARC.
• assign / retain / copy: go to here for reference. These properties define how the compiler generate the setter accessor.
• readonly / readwrite: if a property is declared as readonly, the compiler will only declare the getter accessor, so that you can not call setter accessor.

This post is deprecated. Refer to Propety, Instance Variable and @synthesize.

Location Service Authorization

1. Set info.plist

For iOS SDK 8.0 and later, we need to set NSLocationWhenInUseUsageDescription and ‘NSLocationAlwaysUsageDescription’ in info.plist file. A sample case is:

1
2
3
4

<key>NSLocationWhenInUseUsageDescription</key>
<string>Do you allow the app to use your location?</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>Are you willing to allow the app to use your location?</string>

The string will appear in the popup dialog. You can leave it as empty, and only the system message will appear in the popup.

MKOverlay

Write your own overlay class (for example, MapOverlay) confirm to MKOverlay, synthesize coordinate and boundingMapRect, so that we can assign value to them while initializing it.

Note that the type of coordinate is CLLocationCoordinate2D with latitude and longitude, while boundingMapRect is MKMapRect. And we need to use MKMapPointForCoordinate method to convert a CLLocationCoordinate2D type data to MKMapPoint type data. If we assign the CLLocationCoordinate2D data directly to boundingMapRect, the overlay will be too small to draw, and the mapView:rendererForOverlay: method will not be called at all. It is very hard for debugging.

[updated 2015.09.13] This adding method is only for my project pages (gh-pages) GitBlogs, and for octopress, the way is builded in.

[updated 2015.06.07] For adding category or tag automatically through python script, go to here.

Introduction

The index page includes cat_tag_for_index.html for showing all the categories and tags, and the number of the corresponding posts.

The _layouts/default.html describes the content of a post, because post includes it. In the _layout/default.html file, it includes the cat_tag.html template as the category and tag info in the beginning of the post. And cat_tag.html also includes the date behind.

_data/categories.yml and _data/tags.yml describe all the categories and tags.

Contents

• Check Current Status
• Branch Operation
• Use git commit –amend
• Check commit history
• .gitignore
• Using git stash
• Use kdiff3 as the default tool for git

[updated 2015.10.30] The followings ways for deploying posts is deprecated. Refer to deploying octopress for details. But if you knows things this post descripbes, you will have better understanding of octopress.

[updated 2015.09.13] Github has two kind of pages: user/orgnization pages and project pages (gh-pages).

Currently, I am using the user/orgnization pages deployed by octopress. This is recommended, due to the easy deployment.

If you are using the project pages (gh-pages), the following references may be help.

How to get started

Refer to “一步步在GitHub上创建博客主页”.

Categories and tags

I tried the this one. It works well.

Jekyll debugging

I didn’t try the debugger yet.

The page is from MIT. Keeping here only for reference.

Startup and Help

[updated 2015.10.30] The following way is for my previous blog, and now I am using octopress for my blog.

The following is for my project pages (gh-pages) GitBlogs.

The python script is put GitBlogs/tools/add.py.

For adding category or tag:

• go to tools/
• run python add.py -category category_name or python add.py -tag tag_name for adding category and tag respectively.

Vim is an editor to create or edit a text file.

Two modes:

• command mode: move around, copy and past
• insert mode: insert text

[updated 2015.10.30] The following way is deprecated, and octopress way is prefered. But the To make the post searchable by Google part is still in use.

Contents:

• To add a new post
• To add a new “category” or “tag”
• To enable code highlight
• To make the post searchable by Google
• Some tips for markdown grammar

The first two sections are only for my project pages (gh-pages) GitBlogs, and currently in cotopress blog, we have other new simpler ways to do these things. See Migrate Blog to Octopress.

Description

This post is not for how to deploy the environment of writing posts in github pages, but how to use the environment you deployed before.

Start Developing in a New Mac Machine

[updated on 2015.9.17] With Xcode 7, we only need an Apple ID for deploying your app to ipad or iphone, with the ability to debug.

Object

Define a function addTimer, to log executed time for all function-type property of an object

Definition 1