Android journey 1@关于编码风格和命名规范

/*

* 1.关于编程风格：每一位程序猿可能都有自己独特的编程风格，但是有些规则是大家都必须遵守的，特别

*   是在工作的过程中，良好的代码风格能大大提高代码本身的可阅读性和维护性，也更有利于别人修改你

*   的代码。风格问题涉及到的都是细节相关的问题，读者朋友们或许都听过“细节决定成败”这句话，这句话

*   在这里同样生效，不过是换了种意思，就是“细节体现你的专业程度”，所以作为一名程序猿，我们应该从

*   编写代码的训练中养成良好的编码习惯，如命名规范，排版规范，写好注释等。下面具体说明下：

*/

/*

* 1）整个Project相关内容的目录规范：（通常可以包含以下几个文件夹）

*    #.Requirement Doc: project的需求文档说明

*    #.Design：有关设计方面的说明

*    #.Planning&Log：计划、日志、会议等

*    #.Test：测试及其报告

*    #.Study:学习资料及demo

*    #.Deployment:发布，部署

*    #.src: 源代码

*    #.help：帮助文档

*    #. ...（根据自己需求添加合适文档）

*    注意事项：在IDE建立project的时候，包即目录（java），包名全小写，且一般不超过3层，命名为：【公司】.【项目】.【模块】

*/

/*

* 2）命名规范：

*    #、Pascal命名法：每个单词首字母大写，其余小写，如“ActivityDemo”，主要应用于：文件名，普通类名，构造函数等

*    #、Camel命名法：第一个单词全小写，其余单词按pascal命名，如“myName”,主要应用于：方法名（动宾短语），普通函数名等

*    #、匈牙利命名法（使用前缀，后缀命名）：如对于整型变量，可以“int intMyAge;”

*    #、下划线命名法：主要在常量（全大写）中使用，分隔两个不同单词

*    其他常见命名：私有成员变量：“mMyName”;静态变量：“sMyName”;方法参数：“pMyName”；

*    当然命名规则的使用主要看已有项目的要求，若新启动一个项目，编码前团队必须先统一命名规范

*/

/*

* 3)其他需要注意的地方：

*   1、一个方法不超过35行代码

*   2、不要去修改机器自动生成的代码

*   3、final String取代String，即不要直接写字符串

*   4、循环语句中不用return

*   5、属性用set(),get()方法操控

*   6、不要再系统生成函数中写复杂代码，复杂代码通常用函数调用解决

*   7、虽然class能搞定一切，但使用接口暴露信息会更好

*   8、switch语句中无论如何都要有default

*   9、同类的import包放在一起

*   ...
*

*/

//下面看一下Android源码中的代码：



/*

 * Copyright (C) 2006 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *      http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */



package android.app;



import com.android.internal.app.ActionBarImpl;

import com.android.internal.policy.PolicyManager;



import android.os.Build;

import android.os.Bundle;

import android.os.UserHandle;

import android.text.Selection;

import android.text.SpannableStringBuilder;

import android.text.TextUtils;

import android.text.method.TextKeyListener;

import android.util.AttributeSet;

import android.util.EventLog;



/**可在注释中嵌入HTML标签，在生成javadoc的时候控制各种属性等

 * An activity is a single, focused thing that the user can do.  Almost all

 * activities interact with the user, so the Activity class takes care of

 * creating a window for you in which you can place your UI with

 * {@link #setContentView}.  While activities are often presented to the user

 * as full-screen windows, they can also be used in other ways: as floating

 * windows (via a theme with {@link android.R.attr#windowIsFloating} set)

 * or embedded inside of another activity (using {@link ActivityGroup}).

 *

 * There are two methods almost all subclasses of Activity will implement:

 * 

 * <ul>

 *     <li> {@link #onCreate} is where you initialize your activity.  Most

 *     importantly, here you will usually call {@link #setContentView(int)}

 *     with a layout resource defining your UI, and using {@link #findViewById}

 *     to retrieve the widgets in that UI that you need to interact with

 *     programmatically.

 * 

 *     <li> {@link #onPause} is where you deal with the user leaving your

 *     activity.  Most importantly, any changes made by the user should at this

 *     point be committed (usually to the

 *     {@link android.content.ContentProvider} holding the data).

 * </ul>

 ...

 */

public class Activity extends ContextThemeWrapper

        implements LayoutInflater.Factory2,

        Window.Callback, KeyEvent.Callback,

        OnCreateContextMenuListener, ComponentCallbacks2 {

    private static final String TAG = "Activity";

    private static final boolean DEBUG_LIFECYCLE = false;



    /** Standard activity result: operation canceled. */

	//常量命名

    public static final int RESULT_CANCELED    = 0;

    /** Standard activity result: operation succeeded. */

    public static final int RESULT_OK           = -1;

    /** Start of user-defined activity results. */

    public static final int RESULT_FIRST_USER   = 1;



    static final String FRAGMENTS_TAG = "android:fragments";



    private static final String WINDOW_HIERARCHY_TAG = "android:viewHierarchyState";

    private static final String SAVED_DIALOG_IDS_KEY = "android:savedDialogIds";

    private static final String SAVED_DIALOGS_TAG = "android:savedDialogs";

    private static final String SAVED_DIALOG_KEY_PREFIX = "android:dialog_";

    private static final String SAVED_DIALOG_ARGS_KEY_PREFIX = "android:dialog_args_";



    private static class ManagedDialog {

        Dialog mDialog;

        Bundle mArgs;

    }

    private SparseArray<ManagedDialog> mManagedDialogs;



    // set by the thread after the constructor and before onCreate(Bundle savedInstanceState) is called.

	//私有变量命名

    private Instrumentation mInstrumentation;

    private IBinder mToken;

    private int mIdent;



    static final class NonConfigurationInstances {

        Object activity;

        HashMap<String, Object> children;

        ArrayList<Fragment> fragments;

        HashMap<String, LoaderManagerImpl> loaders;

    }

    /* package */ NonConfigurationInstances mLastNonConfigurationInstances;

    

    private Window mWindow;



    /** 

     * Change the intent returned by {@link #getIntent}.  This holds a 

     * reference to the given intent; it does not copy it.  Often used in 

     * conjunction with {@link #onNewIntent}. 

     *  

     * @param newIntent The new Intent object to return from getIntent 

     * 

     * @see #getIntent

     * @see #onNewIntent

     *自定义javadoc标签

     *@author ..

     *@date  ..

     *@modify  ..(who,when..)

     */ 

    public void setIntent(Intent newIntent) {

        mIntent = newIntent;

    }