• <ins id="pjuwb"></ins>
    <blockquote id="pjuwb"><pre id="pjuwb"></pre></blockquote>
    <noscript id="pjuwb"></noscript>
          <sup id="pjuwb"><pre id="pjuwb"></pre></sup>
            <dd id="pjuwb"></dd>
            <abbr id="pjuwb"></abbr>

            Overview

            Applications on Symbian OS use a standard set of conventions to name their classes, structs, variables, functions, macros, enumerations, and constants. This topic explains the meaning of these conventions.

             

            Class names 

            Most class names are formed with a prefix letter C, T, R, or M. Briefly, the meaning of these is as follows: 

          1. C: heap-allocated classes, that are derived from a base class CBase

          2. T: value classes, that do not own any external object

          3. R: resource classes, that contain handles to a real resource which is maintained elsewhere

          4. M: interface classes, that define abstract protocol definitions that are implemented by derived classes

            Classes that consist solely of static member functions have no prefix letter. Beyond the prefix, the class name is usually a noun that indicates the purpose of the class.


            Struct names

            Structure types are considered as similar to T classes, as they should not own external objects, and are normally given names beginning with T (although some begin with S).


            Variable names

            Member variables names begin with i, e.g. iMember. This makes it easy to check that certain cleanup-related rules are being obeyed. Arguments names begin with a, e.g. aControl or aIndex. Local variables names have no initial letter. Global variables are usually avoided, but when used, their names begin with a capital letter.

            Symbian OS does not use Hungarian or any notation which attempts to include the variable type in its name: such notations are ugly, and become impossible to manage when there are several hundred classes in the system. They are irrelevant anyway: functions are usually so short that it is easy to see the types of variables defined in them, and class browsers provide a quick way to find the types of class members.


            Function names

            Functions names indicate what they do. They are usually verbs. One exception is getter functions: for a function which returns the value of a member variable, the function name is usually the name of the variable, without the leading i:

            inline RWindow& Window() const { return iWindow; };

            A corresponding setter function would include the word Set, e.g. SetWindow().

            To terminate functions because of error conditions, Symbian OS does not use standard C++ exception handling, but its own system called leaving (see Cleanup Support Overview). Any function that might leave has a name ending in ...L(). This makes the fundamental process of checking for errors easier. The new (ELeave) function might also leave. The fundamental leaving function is User::Leave(). Any function that contains any of these, and does not trap them, might itself leave, and should be coded with a trailing L in its name. If a function calls another which might leave, then its name should have the L suffix also.

            Associated with the leaving mechanism, is the cleanup stack, which allows memory allocated on the heap to be recovered when a leave occurs. An allocation or construction function which places data on the cleanup stack ends with ...LC(). For instance, many new, PushL(), ConstructL() sequences are encapsulated in a NewLC() function:

            CS* s=CS::NewLC(p1, p2);

            This allocates the object, initialises it, and leaves it on the cleanup stack. This process may leave (if only through the PushL()!), so such functions always include an L, and are therefore ...LC().

            A function which takes ownership of its object and destroys it has a name ending in ...D(). An example is the UI framework dialog protocol:

            CEikDialog* dialog=new (ELeave) CBossSettingsDialog;
            if (dialog->ExecuteLD(R_BOSS_SETTINGS_DIALOG))
                {
                // handle successful settings
                }

            The ExecuteLD() function includes second-phase construction, execution of the dialog and then destruction.


            Macro names

            Macro names are all capitalised, with underscores to separates words.


            Enumeration names

            Enumerations are named as follows:

            • as enumerations are types, they have the T prefix
            • enumeration members have the prefix E
            • type and members should have a meaningful, unambiguous name

            Enumerations should be scoped within the relevant class, so as not to pollute the global name space.

            An example of the declaration and use of an enumeration is as follows:

            class TDemo
                {
            public:
                enum TShape {EShapeRound, EShapeSquare};
                };

            TDemo::TShape shape=TDemo::EShapeSquare;



            Constant names

            Names of constants have a prefix K. For example,

            const TInt KMaxNameLength=0x20;

          5. Feedback

            # re: Name Conventions for Applications on Symbian OS  回復  更多評論   

            2008-04-27 14:59 by cheney
            支持!

            posts - 1, comments - 5, trackbacks - 0, articles - 2

            Copyright © cheney

            国产精品99久久久久久www| 久久这里有精品| 97久久精品无码一区二区天美 | 99久久精品免费看国产一区二区三区 | 四虎久久影院| 无码人妻久久一区二区三区| 久久久久久狠狠丁香| 99久久做夜夜爱天天做精品| 精品人妻久久久久久888| 久久国产精品免费一区| 久久久亚洲欧洲日产国码二区| 亚洲国产精品一区二区久久| 亚洲AV伊人久久青青草原| 国产成人精品白浆久久69| 四虎影视久久久免费观看| 99久久综合狠狠综合久久止| 亚洲精品无码久久久| 国产91色综合久久免费| 免费精品久久天干天干| 久久996热精品xxxx| 韩国三级大全久久网站| 亚洲AV日韩AV永久无码久久| 亚洲色欲久久久久综合网| 久久综合久久综合久久| 久久久久亚洲精品无码蜜桃| 久久婷婷午色综合夜啪| 久久久久亚洲精品男人的天堂| 国产精品久久99| 国产产无码乱码精品久久鸭| 婷婷伊人久久大香线蕉AV | 国产精品嫩草影院久久| 久久久久久久尹人综合网亚洲 | 一个色综合久久| 免费精品国产日韩热久久| 久久精品一区二区三区中文字幕| 91精品国产色综合久久| 97r久久精品国产99国产精| 99久久免费国产特黄| 久久综合久久久| 久久人人超碰精品CAOPOREN| 久久国产综合精品五月天|