Visual Basic language and arithmetic
The United States launched the Microsoft Visual Basic (may be referred to VB), is the latest version of the current VB 2008 Beta2 (VB9) Chine version.
Visual meaning the visual, visible, referring to the development of operating systems like windows graphical ur interface (Graphic Ur Interface, GUI) method, it does not need to prepare a large number code to describe the appearance of the interface elements and location, as long as the pre - The establishment of good drag and drop objects on the screen corresponding to the location.
Basic is actually an abbreviation of the phra; this phra is Beginners all-purpo symbolic instruction code, the Chine meaning "to the initial directive GM symbol code language."
Visual Basic learning, Professional Edition and Enterpri Edition versions to meet the different needs of the development. Study and apply to the ordinary version of the majority of learners and the u of Visual Basic development of the general staff of Windows applications, but; professional version for computer professional development of staff, including the study of functional version of the full content control and Internet development tools such as advanced features ,Enterpri contain not only all the professional version of the content, there are automated tools such as Component Manager, professio
nal programmers to make the development of a powerful group esnce of distributed applications.
Visual Basic
Section 1 the summary of Visual Basic
Microsoft Visual Basic,( abbreviate VB )as tool the most of application program one of under Windows operating platform. No matter beginner or professional developer, VB has all offered a whole t of tools to them, Development application program that it can be relaxed and convenient. So VB as most computer first-lected the ABC of programming language of beginner.
" Visual" mean method to adopt visual ur of development figure interface (GUI), need and write a large number of code go and describe interface appearance and position of element ldom, Tow and show controlling part that need corresponding position to get screen can help figure design interface, ur of figure,; " Basic" means BASIC language, becau VB is developed on the basis of already existing BAISC language.
VB is a kind of programming language in common u of Microsoft, It, including VBA of the numerous Windows application software u VB language in Microsoft Excel, Microsoft Accesd., F
or urs to carry on the condary development; Make web page u more VBScript script language sub collection of VB too at prent.
Utilize data of VB visit characteristic ur can establish the data ba to most data ba forms including Microsoft SQL Server and other enterpris data ba With the application program of front, and adjustable rvice end part. Utilize ActiveX(TM) technology, VB can u word processor, electronic data list he Windows function that application program offers extremely, Excel of Microsoft,, Word of Microsoft,, Even can u by VB specialty edition or enterpri application program and target that
edition establish directly.
The procedure that urs established finally is a real .EXE file , can issue freely .
VB offer study edition, the specialty edition and enterpri edition, u to satisfied with different development demands. Study edition make programming personnel develop Windows and Windows application program of NT very easily. The specialty edition has offered the developing instrument with complete function to programming personnel of the specialty, Include studying all functions of edition in the specialty edition. Enterpri edition allow the professional personnel to establish strong
distributed application program in the form of group. It includes all characteristics of the specialty edition. So can choo different editions according to different needs.
Section 2 integrated development environments
Integrated environment of VB call IDE, made up of a lot of parts , include title board, menu fence, tool fence, controlling part ca, And window body window, engineering management device window, attribute window, code window and window body overall arrangement window body overall arrangement, etc. of designing etc.. Have covered all functions, such as design which develops the application program, editting, compiling and debugging, etc..
In VB, the application program calls the project too. When start VB and open a new project for the first time, can e and pursue integrated development environment interface that show.
Visual Basic Integrated development environment
VB come and organize development of application program through project, u project come and manage and form files of application program. One project us the environment to make up by veral window bodies, standard module generally. The system manages project through the project
menu, for instance add the window body, quote . System allow turn on and manage a lot of projects besides.
Section 3 Visual Basic language brief introductions
Basic u and do the elementary high-level language that ud often most. Its full name is Beginner' s All-purpo Symbolic Instruction Code, abbreviate as BASIC. As its name suggests, Basic one specially for language that beginner design, becau it easy to learn easy to know, So the body is popular. Early Basic language to belong to and solve translating type, so can carry out line by line , So it can e the result carried out at once , this is a very convenient design for beginner. But it have concept of structure either, one that is in procedure maintain and management have as much as other language problems. But back-end Basic correct shortcoming of the above (such as Quick Basic), make it may ud for and develop the large-scaler procedure too.
The language is the basic composition, which forms VB procedure. VB has stipulated the form of ntences and function.
Grammar:
The ntence defines incantations [Sentence body]
Sentence define agree with and ud in fixed function of ntence, ntence body appoint concrete content or want concrete operation that carry out of ntence. All t of ntence VB language, carry on with VB ntence organic association finish a
certain specific function the procedure. Interface + procedure can solve a certain application problem.
VB application program code window write in" code editing machine" generally. " editing machine of code" is like the word processing software of a piece of height specialization, there are many easies function of writing VB code, Pursue to show [Example Ex-Hello ]In" code editing machine" code that window written.
“Editing machine of code” window
Section 4 develop the application program with Visual Basic
U VB programming, design appearance of application program first generally, write every target procedure code or other treatment procedure of incident respectively, Work of programming should be light more.
The procedure of establishing the application program is as follows:
Establish application program interface
The interface is the mutual bridge of ur and procedure, Generally formed of window body and vision frame of the button, menu, text framet. with standard WINDOWS interface of application program that VB establish. Require according to function of procedure and ur and need of information interchange of procedure, Come to confirm that need tho targets , plan the overall arrangement of the interface.
2. Design by each attributes of target in interface
Demand and t up each attribute of target such as appearance, name,, size of targeted. according to interface of planning.
Most attribute person who fetch can t up through the attribute window when design already, Too can t up revising when operating in procedure through programming in procedure code. Have the targets respond programming by procedure code
3. Respond procedure code of programming target
Interface determine appearance of procedure only, design window add codes through" code editing machine" soon after the interface, Realize some make the tasks, such as responding, information processing,etc. after accepting external message, Add code , realize some respon, information processing that make after accepting external information task, As editor's window of code pursued shows add codes “code editing machine” wi ndow
4. Keep project
One VB procedure one project, at the time of designing a application program, system will t up one be expanded and called. Project file of vbp, project file include all relevant information of file that project t up this, Keep project keep associated documents of project this at the same time. For example the window body produced when design interfaces is kept and being expanded and being called. Frm sum. In the window body of foxfire. At the time of opening a project( file), this project relevant files load at the same time.
5. Operate and debugged by procedure
Operate the procedure thoroughpin operate" lecting in the menu, when the mistake appears, VB system can offer information prompt can looked for and get rid
of the mistake thoroughpin debug" within operate" menus too.
6. Can produce by executive program
For make procedure can break away from VB environment, order to become next life through" file"" producing " of menu but executive program (eyeful), Can carry out this file directly after this. In produce, + executive program, and then through install guide bale all associated documents, Can run independently after installation under the environment of windows 9 x/2000 as a software product.
In computer system's any software, is by the every large or small each kind of software constituent constitution, defers to the specific algorithm to realize respectively, the algorithm quality direct decision realizes the software performance fit and unfit quality. Designs the algorithm with any method, what resources designs the algorithm to need, requires how many running time, how many storage space, how to determine an algorithm the quality, when realizes a software, is must give to solve. In computer system's operating system, the language compiling system, the databa management system as well as in various computer application system's software, must u each one concrete algorithm to realize. Therefore, the algorithm design and the analysis are the computer science and a technical core question.
The algorithm is the problem-solving step, we may define the algorithm Cheng Jie a determination class question the random one special method. In the computer science, the algorithm needs to u the computer algorithmic language to describe, the algorithm reprents with the computer solves a kind of question precily, the effective method. The algorithm construction of data = procedure, solves one to assign may calculate or the solvable question, the different person may compile the different procedure, solves the identical problem, here has two problems: First, with computational method clo related algorithm question; Second, programming technical question. Between the algorithm and the procedure has the clo relationship. The algorithm is a group has the poor rule, they had stipulated solves some specific type question a ries of operations, is to the problem solving plan accurate and the complete description. Formulates an algorithm, generally must pass through stages and so on design, confirmation, analysis, code, test, debugging, time. To algorithm study including five aspect contents:① Design algorithm. The algorithm design work is impossible completely the automation, should study the understanding already by the practice to prove that was the uful some basic algorithm design method, the basic design method was not only suitable for the computer science, moreover was suitable for domains and so on electrical engineering, operations rearch;②Express the algorithm. The description algorithm's method has many kinds of forms, for example the natural language and the algorithmic language, have the suitable environm
ent and the characteristic respectively;③Confirms the algorithm. The algorithm confirmed the goal is caus the people to believe firmly that this algorithm can work unmistakably correctly, namely this algorithm has the circularity. The correct algorithm describes with the computer algorithmic language, constitutes the computer program, the computer program moves on the computer, obtains the
algorithm operation result;④ Parsing algorithm. The algorithmic analysis is requires how many computing time and the storage space to an algorithm makes the quota the analysis. The parsing algorithm may forecast that what environment this algorithm does suit in moves effectively, to solves the identical question different algorithm validity to make the comparison;⑤ Confirmation algorithm. With machine language description algorithm whether can calculate effectively, reasonable, must carry on the test to the procedure, the test order work and makes the space and time distribution map by the debugging to be compod.
But the algorithm has certain characteristic, it includes:①Determinism. Algorithm each kind of operation must have the determination significance, this kind of operation should carry out what kind of movement should not to have the ambiguity, the goal is clear;②Effectiveness. Requests the operation which in the algorithm waits for realizing is basic, each kind of operation can at least compl
etes in the principle by the human with the paper and the pen in the limited time;③ Input. An algorithm has 0 or the many inputs, before the algorithm operation starts gives the algorithm to need the data the starting value, the inputs are from the specific object t;④Output. Does for the algorithm operation result, an algorithm has or many outputs, the output has some kind of specific relational quantity with the input;⑤ Has poor. An algorithm always after carrying out had the poor step operation has terminated, namely this algorithm was may reach.
Satisfies a first four characteristic group of rule not to be able to be called the algorithm, can only be called the computational process, the operating system is a computational process example, the operating system us for to manage the computer resources, controls the manufacture industry movement, when has not made industry the movement, the computational process does not stop, but is at the waiting status.
The algorithm complexity is the algorithm efficiency measure, when apprais the algorithm performance, the complexity is an important basis. The algorithm complex degree with moves computer resources how many which this algorithm needs related, needs the resources are more, indicated that this algorithm the complexity is higher; Needs the resources are less, indicated that this algorithm the complexity is lower.
The spatial resources, which computer’s resources, operate most importantly, needs the time which and the stored routine and the data need, the algorithm complexity has division time complexity and the spatial complexity.
The algorithm carries out the operation on the computer, needs the data which certain storage space depositing description algorithm the procedure and the algorithm need, the computer completes the operation task to require certain time. The procedure which writes according to the different algorithm places when on the computer operates, needs the time and the space are different, the algorithm complexity is needs the time and the spatial one kind of measure to the algorithm operation. The different computer its operating speed difference is very big, is weighing an algorithm the complexity to note this point.
Regarding question, which assigns willfully, a profitable target which designs,
