1
, "&" Replace " " In many people's programming languages, use " " to connect the string, which is easy to cause ambiguity. Good habits are "&" to connect the string.
Incorrect:
Dim SMESSAGE AS STRING
SMESSAGE = "1" "2"
correct:
Dim SMESSAGE AS STRING
SMESSAGE = "1" & "2"
Note: "&" has a space
2, variable name sensation,
Statement is wrong with rank, source code maintenance
Here's you compare the following two codes:
Read the code that is difficult to know:
DIM sname as string
DIM NTURN AS INTEGER
IF NTURN = 0 THEN
IF sname = "vbeden" then
Do while NTURN <4
NTURN = NTURN 1
Loop
END IF
END IF
Easy to read the code:
DIM sname as string
DIM NTURN AS INTEGER
IF NTURN = 0 THEN
IF sname = "vbeden" then
Do while NTURN <4
NTURN = NTURN 1
Loop
END IF
END IF
3 Please develop the following "object naming conventions" good habits
Recommended control prefix
Control type prefix example
3D PANEL PNL PNLGroup
ADO Data Ado Adobe Iblio
Animated Button Ani Animailbox
Check Box Chk ChkReadonly
Combo Box, Drop-Down List Box CBO CBOENGLISH
Command button cmd cmdexit
Common Dialog Dlg DlgfileOpen
Communications COM Comfax
Control (when a specific type is unknown, in the process) CTR Ctrcurrent
Data Dat Datbiblio
Data-Bound Combo Box DBCBO DBCBOLANGUAGE
Data-Bound Grid DBGRD DBGRDQUERYRESULT
Data-Bound List Box DBLST DBLSTJOBTYPE
Data Combo DBC DBCAUTHOR
Data Grid DGD DGDTISLES
Data List DBL DBLPUBLISHER
Data Repeater Drp Drplocation
Date Picker DTP DTPPBLISHED
Directory List Box Dir Dirsource
Drive List box drv drvtarget
File List Box FilSource
Flat Scroll Bar FSB FSBMOVE
Form FRM FRMENTRY
Frame fraranguage
Gauge Gau Gaustatus
Graph gra grandevenue
Grid GRD GRDPRICES
Hierarchical FlexGrid Flex Flexorders
Horizontal Scroll Bar HSB HSBVOLUME
Image IMG IMGICON
Image Combo Imgcbo IMGCBOPRODUCT
ImageList Ils Ilsallicons
Label LBL LBLHELPMESSAGE
LightWeight Check Box LWCHK LWCHKARCHIVE
Lightweight Combo Box LWCBO LWCBOGERMAN
Lightweight Command Button LWCMD LWCMDREMOVE
Lightweight Frame LWFRA LWFRASAVEOPTIONS
Lightweight Horizontal Scroll Bar LWHSB LWHSBVOLUME
Lightweight List Box LWLST LWLSTCOSTCENTERS
Lightweight Option Button Lwopt LwoptIncomeLevel
LightWeight Text Box LWTXT LWOPTSTREET
Lightweight Vertical Scroll Bar LWVSB LWVSBYEAR
Line Lin Linvertical
List box Lst LstpolicycoDes
Listview lvw lvwheadings
Mapi Message MPM MPMSentMessage
Mapi session MPS MPSSession
MCI MCI McIvideo
Menu Mnu Mnufileopen
Month View MVW Mvwperiod
MS Chart Ch ChsalesbyRegion
MS Flex Grid Msg MsgClients
MS Tab MST MSTFIRST
Ole Container Ole Oleworksheet
Option Button Opt Optgender
Picture Box Pic Picvga
Picture CLIP CLP CLPToolbar
ProgressBar PRG prgloadfile
Remote Data Rd Rdtitles
RichtextBox RTF RTFreport
Shape SHP SHPCIRCLE
Slider SLD SLDScale
Spin SPN SPNPAGES
Statusbar Sta StadateTime
Sysinfo Sys Sysmonitor
Tabstrip Tab TabOptions
Text box txt txtlastname
Timer TMR Tmralarm
Toolbar TLB TLBACTIONS
TreeView Tre Treorganization
Updown UPD UPDDIRECTION
Vertical Scroll Bar vsb vsbrate
-------------------------------------------------- ------------------------------
Recommended Data Access Object (DAO) prefix
Use the following prefix to indicate data access objects
Database object prefix example
Container ConReports
Database DB DBACCOUNTS
DBENGINE DBE DBEJET
Document Doc DocsalesReport
FIELD FLD FLDDRESS
GROUP GRP GRPFINANCE
Index IX IDXAGE
Parameter prmjobcode
QueryDef Qry QrysalesbyRegion
Recordset Rec Recforcast
RELATION REL RELEMPLOYEDEPT
Tabledef TBD TBDCUSTOMERS
User usr usrnew
Workspace WSP Wspmine
-------------------------------------------------- ------------------------------ Application frequently uses many menu controls, which has a set of unique naming conventions for these controls. . In addition to the top "MNU" tag, the prefix of the menu control should be extended: add an additional prefix for each stage, put the header of the final menu in the last menu. The following table lists some examples.
Recommended menu prefix
Menu Title Sequence Menu Processor Name
File Open Mnufileopen
File Send Email Mnufilesendemail
File Send Fax Mnufilesendfax
Format Character MnuFormatcharacter
Help Contents MNUHELPCONTENTS
When using this naming convention, all members of a specific menu group take one of the listings in the "Properties" window of Visual Basic. Moreover, the name of the menu control clearly shows the menu items they belong.
Select prefix for other controls
For controls listed above, you should use the unique prefix consisting of two or three characters to standardize to keep consistency. More than three characters are used only when it is necessary to clarify.
Constants and variable naming conventions
In addition to objects, constants and variables also require a good format naming convention. This section lists the recommendations of constants and variables supported by Visual Basic. And discuss issues that identify data types and ranges.
Variables should always be defined within a small range as possible. The global (public) variable can lead to extremely complex state agencies, and make the logic of an application very difficult to understand. Global variables also make the reuse and maintenance of the code more difficult.
Variables in Visual Basic can have the following range
Scope declaration location visible location
Process grade process, sub-process or function of 'private' during declaring it
Module-Level Forms or Code Module (.frm, .bas) declaration section of the 'private' form or code module
Each of the 'Public' application in the declaration section of the global code module (.bas)
In Visual Basic's applications, global variables are only used when there is no other convenient way to share data between the form. When you have to use global variables, they declare them in a single module and packet according to the function. Take a meaningful name to this module to indicate its role, such as public.bas.
Good coding habits are to write modular code as much as possible. For example, if the application displays a dialog, all controls and code you want to complete this dialog task are placed in a single form. This helps to use the application's code organization in useful components and reduce the overhead of its runtime.
In addition to global variables (should be not delivered), processes and functions should only be operated only for objects passed to them. The global variable used in the process should be identified in the declaration section of the process start. In addition, you should deliver parameters to the SUB process and the Function process, unless it is clear that the passed parameter value is changed.
With the growth of project size, the work of dividing variable ranges is also increased. The single-alphabet prefix is launched in front of the type prefix indicates this growth, but the length of the variable name does not increase.
Variable range prefix
Range prefix example
GGSTRUSERNAME
Modular grade M MblncalcinProgress
Local until there is no dblvelocity
If a variable is declared in the standard module or form module as public, then the variable has a global range. If a variable is declared as private in a standard module or form module, then the variable has a modular level.
Note: Consistency is a key to use this technology. The syntax inspector in Visual Basic does not capture module-level variables starting with "p.". constant
The main body of constant quantities is mixed, and the first letter of each word is capitalized. Although standard Visual Basic constants do not contain data types and range information, prefixes such as I, S, G, and M are still very useful for understanding the value and range of a constant. For constant names, the same rules as variables should be followed. E.g:
MINTUSERLISTMAX 'Maximum limit on the user list
'(Integer value, local to module)
GSTRNEWLINE 'new line characters
'(String, global use of applications)
variable
Declarening all variables will save programming time, because the error caused by typing operations is reduced (for example, is AUSERNAMETMP, or SUSERNAMETMP, or SUSERNAMETEMP). In the Editor tab of the Options dialog, check the "Requirements Variable Declaration" option. Option EXPLICIT statement requires that all variables are declared in the Visual Basic program.
It should be given to the variable to indicate their data type. Moreover, the prefix can be expanded to indicate the range of variables, especially for large programs.
Use the following prefix to indicate the data type of a variable.
Variable data type
Data type prefix example
String (string type) str strfname
Integer (Short Negative Type) Int IntQuantity
Long (Long Integer Type) LNG LNGDISTANCE
SINGLE (single-precision floating point number) SNG SNGAVERAGE
Double (double precision floating point type) DBL DBLTOLERANCE
Boolean (Boolean) BLN BLNFOUND
Byte (byte type) ByT ByTRASTERDATA
Date (Date type) DTE DTENOW
Currency (currency calculation and fixed point calculation type) CUR Currevenue
Object (object type) Obj Objcurrent
Variant (variant type) VNT VNTCHECKSUM
Describe variables and process names
The subjects of the variable or process name should be in size and should be sufficiently long enough to describe its role. Moreover, the function name should be in one verb, such as initNameArray or Closedialog.
For frequently used or long items, standard abbreviations are recommended to rationalize the length of the name. In general, the variable name of more than 32 characters is difficult to read on the VGA display.
When using a thumbnail, make sure they are consistency throughout the application. In one project, if you use CNT for a while, you will use count, which will result in unnecessary confusion.
User-defined type
In a big project with many user-defined types, it is often necessary to give each type of one of its own three characters prefixed. If these prefix starts with "U", quickly identify these types when using a user-defined type. For example, UCLI can be used as a prefix for a user-defined customer type variable.
4 Use the IIF () function in a simple selection condition
Rosso code:
IF nnum = 0 THEN
Sname = "Sancy"
Else
Sname = "xu"
End IF simple code:
SNAME = IIF (nnum = 0, "SANcy", "XU")
5, try to use Debug.print for debugging
In the commissioning of many beginners, use MSGBOX
Track the variable value. In fact, debug.print can not only reach the same effect, but also in the final compilation process of the program. The MSGBOX must be manually annotated or deleted.
usually:
Msgbox nname
should:
Debug.print nname
6,
Try to use with .... end with when you repeat the properties of a certain object
usually:
Form1.height = 5000
Form1.width = 6000
FORM1.CAPTION = "this is mylabel"
should:
WITH FORM1
.HEight = 5000
.Width = 6000
.Caption = "this is mylabel"
End with
This structural program performs high efficiency, especially in the cycle statement.
7.
Msgbox Try to use the message icon as much as possible, this program is more specified
Generally
Vbinformation is used to prompt the message to confirm or successfully operate
Vbexclamation is used to prompt the message
Vbcritical is used to prompt the crisis
Vbquestion is used to prompt the message
8,
Use enumeration in may be
The format of the enumeration is
[Public | private] enum name
Membername [= constantExpression]
Membername [= constantExpression]
....
END ENUM
The ENUM statement contains the following sections:
Partial description
Public is optional. Indicates that the Enum type is visible throughout the project. The default situation of the Enum type is public.
Private is optional. Indicates that the Enum type is only visible only in the declared module.
Name must be. The name of the enum type. Name must be a legitimate Visual Basic identifier that specifies the type with this name when defining a variable or parameter of the enum type.
MEMBERNAME is required. A legitimate Visual Basic identifier for specifying the constituent element name of the enum type.
Constantexpression is optional. The value of the element (for long type). Can be an other ENUM type. If there is no ConstantExpression, the value is given or 0 (if the element is the first memory), or the value is larger than its direct forward.
Description
The so-called enumeration variable refers to the variable defined with the enum type. Variables and parameters can be defined as an ENUM type. Elements in the ENUM type are initialized to the constant value specified in the ENUM statement. The value given can include positive and negative numbers, and cannot be changed at runtime. E.g:
Enum security = -1 securityLevel1 = 0 securityLevel2 = 1 END ENUM
The Enum statement can only appear in the module level. Once you define the ENUM type, you can use it to define variables, parameters, or return to this type. You cannot use the module name to limit the enum type. The PUBLIC ENUM type in the class module is not a member of the class; but they are also written to the type library. The ENUM type defined in the standard module is not written in the type library. Public enorm types with the same name cannot be defined in a standard module, and are defined in class modules because they share the same namespace. If there are two eNUM types in different types of libraries, the membership of this type of variable will depend on which type library has a higher reference priority. Enum types cannot be used as the target in the With block.
ENUM statement example
The following example demonstrates a collection of naming constants with an ENUM statement. In this example, some of the color constants that can be selected for designing the data input form of the database.
Public Enum InterfaceColors
ICMistyRose = & HE1E4FF & HE1E4FF & HE1E4FF & HE1E4FF & HE1E4FF & HE1E4FF &
Icslategray = & h908070 & h908070
IcdodgerBlue = & HFF901E & HFF901E &
IcdeepskyBlue = & HFFBF00 &
Icspringgreen = & h7fff00 &
IcForeStgreen = & H228B22 & H228B22 &
Icgoldenrod = & H20A5DA & H20A5DA &
ICFIREBRICK = & H2222B2 & H2222B2 & H2222B2 & H2222B2 & H2222B2 & H2222B2 & H2222B2 &
END ENUM
The advantage is to speed up the programming speed
9 When writing code, you can write a variable using Chinese, and then use English. When you write the code, your thinking is relatively clear, and it is convenient to debug, hehe.
