vb毕业论文外文翻译

Visual Basic编程语言 1991年，美国微软公司推出了Visual Basic(可简称VB），目前的最新版本是VB 2008 Beta2(VB9)中文版。 Visual 意即可视的、可见的，指的是开发像windows操作系统的图形用户界面（Graphic User Interface,GUI）的方法，它不需要编写大量代码去描述界面元素的外观和位置，只要把预先建立好的对象拖放到屏幕上相应的位置即可。 Basic 实际上是一个短语的缩写，这个短语就是 Beginners all_purpose symbolic instruction code ，其中文意思为“初始者通用符号指令代码语言”。 Visual Basic有学习版、专业版和企业版三种版本，以满足不同的开发需要。学习版适用于普通学习者及大多数使用Visual Basic开发一般Windows应用程序的人员，但是；专业版适用于计算机专业开发人员，包括了学习版的全部内容功能以及Internet控件开发工具之类的高级特性；企业版除包含专业版全部的内容外，还有自动化构件管理器等工具，使得专业编程人员能够开发功能强大的组骨子里分布式应用程序。 VB是一种可视化的、面向对象和采用事件驱动方式的结构化高级程序设计语言，可用于开发Windows环境下的各类应用程序。它简单易学、效率高，且功能强大可以与Windowsr专业开发工具SDK相媲美。在Visual Basic环境下，利用事件驱动的编程机制、新颖易用的可视化设计工具，使用Windows内部的广泛应用程序接口（API）函数，以用动态链接库（DLL）、对象的链接与世隔嵌入（OLE）、开放式数据连接（ODBC）等技术，可以高效、快速地开发Windows环境下功能强大、图形界面丰富的应用软件系统。随着版本的提高，Visual Basic的功能也越来越强。5.0版以后，Visual Basic推出了中文版，与前个版本相比，其功能有了很大提升。但是，功能再强大，Visual Basic仍然有一个缺点：在没有MSVBVM**.DLL的计算机上必须安装所需的DLL文件。用它可设计操作系统，不过，比较困难。 在二十一世纪初，microsoft公司推出Visual Studio 2003与Visual Basic之间有了重大变化，Visual Studio为各种编程工具做了一个平台，Visual Basic.NET可在这种平台上运行。相对于传统VB，有很大的不同。VB.Net，首次使用.Net构架进行可视化编程，并且能很好地与COM构架兼容。2005年Visual Studio 2005则运用了NET 2.0的技术，更加的方便了程序员的工作。可是新的程序对系统配置要求也较高，需要微软.Net Framework 2.0以上的.Net构架支持。 2007年12月,微软(Microsoft)推出了Visual Studio 2008 Beta 2 发生了重大的变化(见附图)在代码输入的时候,可以比VB2005快很多,在非特殊的情况下,VB2008都会自动开启 自动完成关键字 这个命令 而且开始支持最新的.NET Framework 3.5 Beta 2Visual Basic programming language 1991, the United States launched the Microsoft Visual Basic (may be referred to VB), is the latest version of the current VB 2008 Beta2 (VB9) Chinese version. Visual meaning the visual, visible, referring to the development of operating systems like windows graphical user interface (Graphic User 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 phrase, this phrase is Beginners all_purpose symbolic instruction code, the Chinese meaning "to the initial directive GM symbol code language." Visual Basic learning, Professional Edition and Enterprise Edition versions to meet the different needs of the development. Study and apply to the ordinary version of the majority of learners and the use 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 ; Enterprise contain not only all the professional version of the content, there are automated tools such as Component Manager, professional programmers to make the development of a powerful group essence of distributed applications. VB is a visual, object-oriented event-driven approach and the use of the structure of high-level programming language, can be used for the development of the Windows environment of various applications. It easy to learn, efficient and powerful with Windowsr professional development tools comparable to SDK. In Visual Basic environment, the use of event-driven programming mechanism, the new easy-to-use visual design tools, within the wider use Windows application program interface (API) function, to use dynamic link library (DLL), the object Links embedded with the World at (OLE), open-end data connectivity (ODBC), and other technology, can be highly efficient and rapid development of the Windows environment powerful, rich graphical interface application software system. With the improved version, Visual Basic functions also growing. After version 5.0, Visual Basic launched a Chinese version, compared with the previous version, its functions have been greatly improve. However, more powerful functions, Visual Basic still has one drawback: in the absence of MSVBVM **. DLL must be installed on the computer the required DLL file. It can be designed with the operating system, but more difficult. In the early 21st century, microsoft has introduced Visual Studio 2003 and Visual Basic among the significant changes, Visual Studio for a variety of programming tools to a platform, Visual Basic.NET can run on this platform. Compared with traditional VB, are quite different. VB.Net, used for the first time. Net framework for visual programming, and can a good framework compatible with COM. 2005 Visual Studio 2005则use of the NET 2.0 technology, more convenience to the programmer's work. But the new procedures on the system configuration requirements are also higher, the need for Microsoft. Net Framework 2.0 above. Net framework support. December 2007, Microsoft (Microsoft) launched the Visual Studio 2008 Beta 2 has undergone major changes (see attached map) enter in the code when the VB2005 can be much faster than in non-exceptional circumstances, VB2008 will automatically open automatically Keyword completion of this order and begun to support the latest. NET Framework 3.5 Beta 2

2064个字~Electric circuit exchange network and vb transfer database The result of the connection setup with circuit switching is the reservation of bandwidth all the way from the sender to the receiver. All packets follow this path. Among other properties, having all packets follow the same path means that they cannot arrive out of order. With packet switching there is no path , so different packets can follow different paths, depending on network conditions at the time they are sent. They may arrive out of order.Packet switching is more fault tolerant than circuit switching. In fact, that is why it was invented. If a switch goes down, all of the circuits using it are terminated and no more traffic can be sent on any of them. With Packet switching, packets can be routed around dead switches.Setting up a path in advance also opens up the possibility of reserving bandwidth in advance. If bandwidth is reserved, then when a packet arrives, it can be sent out immediately over the reserved bandwidth. With packet switching, no bandwidth is reserved, so packets may have to wait their turn to be forwarded.Having bandwidth reserved in advance means that no congestion can occur when a packet shows up (unless more packets show up than expected).On the other hand, when an attempt is made to establish a circuit, the attempt can fail due to congestion. Thus, congestion can occur at different times with circuit switching(at setup time) and packet switching(when packets are sent).If a circuit has been reserved for a particular user and there is no traffic to send, the bandwidth of that circuit is wasted. It cannot be used for other traffic. Packet switching does not waste bandwidth and thus is more efficient form a system-wide perspective. Understanding this trade-off is crucial for comprehending the difference between circuit switching and packet switching. The trade-off is between guaranteed service and wasting resources versus not guaranteeing service and not wasting resources.Packet switching uses store-and-forward transmission. A packet is accumulated. in a router’s memory, then sent on to the next router. With circuit switching, the bits just flow through the wire continuously. The store-and-forward technique adds delay.Another difference is that circuit switching is completely transparent. The sender and receiver can use any bit rate, format, or framing method they want to. The carrier does not know or care. With packet switching, the carrier determines the basic parameters. A rough analogy is a road versus a railroad. In the former, the user determines the size, speed, and nature of the vehicle; in the latter, the carrier does. It is this transparency that allows voice, data, and fax to coexist within the phone system.A final difference between circuit and packet switching is the charging algorithm. With circuit switching, charging has historically been based on distance and time. For mobile phones, distance usually does not play a role, except for international calls, and time plays only a minor role(e.g., a calling plan with 2000 free minutes costs more than one with 1000 free minutes and sometimes night or weekend calls are cheaper than normal).With packet switching, connect time is not an issue, but the volume of traffic sometimes is. For home users, ISPs usually charge a flat monthly rate because it is less work for them and their customers can understand this model easily, but backbone carriers charge regional networks based on the volume of their traffic. The differences are summarized in Fig.2-40.Item Circuit Switched Packet SwitchedCall setup Required Not neededDedicated physical path Yes NoEach packet follows the same route Yes NoPackets arrive in order Yes NoIs a switch crash fatal Yes NoBandwidth available Fixed DynamicTime of possible congestion At setup time On every packetPotentially wasted bandwidth Yes NoStore-and-forward transmission No YesTransparency Yes NoCharging Per minute Per packetBoth circuit switching and packet switching are important enough that we will come back to them shortly and describe the various technologies used in detail.2.6 THE MOBILE TELEPHONE SYSTEMThe traditional telephone system(even if it some day gets multi-gigabit end-to-end fiber) will still not be able to satisfy a growing group of users :people on the go .People now expect to make phone calls from airplanes ,cars ,swimming pools ,and while jogging in the park .Within a few years they will also expect to send e-mail and surf the Web from all these locations and more consequently ,there is a tremendous amount of interest in wireless telephony .In the following sections we will study this topic in some detail.Wireless telephones come in two basic varieties :cordless phones and mobile phones(sometimes called cell phones),Cordless phones are devices consisting of a base station and a handset sold as a set for use within the home. These are never used for networking ,so we will not examine them further .Instead we will concentrate on the mobile system ,which is used for wide area voice and data communication.Mobile phones have gone through three distinct generations ,with different technologies:1. Analog voice2. Digital voice3. Digital voice and data(Internet ,e-mail ,etc.).Although most of our discussion will be about the technology of these systems ,it is interesting to note how political and tiny marketing decisions can have a huge impact .The first mobile system was devised in the U.S. by AT&T and mandated for the whole country by the FCC .As a result ,the entire U.S. had a single(analog) system and a mobile phone purchased in California also worked in New York .In contrast ,when mobile came to Europe ,every country devised its own system ,which resulted in a fiasco.Europe learned from its mistake and when digital came around, the government-run PTTs got together and standardized on a single system(GSM),so any European mobile phone will word anywhere in Europe .By then ,the U.S. had decided that government should not be in the standardization business ,so it left digital to the marketplace .This decision resulted in different equipment manufacturers producing different kinds of mobile phones .As a consequence ,the U.S. now has two major incompatible digital mobile phone systems in operation(plus one minor one).Despite an initial lead by the U.S. , mobile phone ownership and usage in Europe is now far greater than in the U.S. Having a single system for all of Europe is part of the reason ,but there is more .A second area where the U.S. and Europe differed is in the humble matter of phone numbers .In the U.S. mobile phones are mixed in with regular (fixed) telephones .Thus ,there is no way for a caller to see if ,say ,(212)234-5678 is a fixed telephone (cheap or free call) or a mobile phone (expensive call).To keep people from getting nervous about using the telephone ,the telephone companies decided to make the mobile phone owner pay for incoming calls .As a consequence ,many people hesitated to buy a mobile phone for fear of running up a big bill by just receiving calls .In Europe ,mobile phones have a special area code (analogous to 800 and 900 numbers) so they are instantly recognizable .Consequently , the usual rule of “caller pays” also applies to mobile phones in Europe (except for international calls where costs are split).A third issue that has had a large impact on adoption is the widespread use of prepaid mobile phones in Europe (up to 75% in some areas ).These can be purchased in many stores with no more formality than buying a radio .You pay and you go .They are preloaded with ,for example ,20 or 50 euro and can be recharged (using a secret PIN code ) when the balance drops to zero . As a consequence , practically every teenager and many small children in Europe have (usually prepaid ) mobile phones so their parents can locate them ,without the danger of the child running up a huge bill .If the mobile phone is used only occasionally ,its use is essentially free since there is no monthly charge or charge for incoming calls .2.6.1 First-Generation Mobile Phones :Analog Voice Enough about the politics and marketing aspects of mobile phones .Now let us look at the technology ,starting with the earliest system .Mobile radiotelephones were used sporadically for maritime and military communication during the early decades of the 20th century .In 1946, the first system for car-based telephones was set up in St.Louis .This system used a single large transmitter on top of a tall building and had a single channel ,used for both sending and receiver .Such systems ,known as push-to-talk systems ,were installed in several cities beginning in the late 1950s.CB-radio,taxis,and police cars on television programs often use this technology. In the 1960s,IMTS(Improved Mobile Telephone System) was installed .It ,too ,used a high-powered (200-watt) transmitter ,on top of a hill , but now had two frequencies ,one for sending and one for receiving , so the push-to-talk button was no longer needed . Since all communication from the mobile telephones went inbound on a different channel than the outbound signals ,the mobile users could not hear each other (unlike the push-to-talk system used in taxis). IMTS supported 23 channels spread out from 150 MHz to 450 MHz .Due to the small number of channels ,users often had to wait a long time before getting a dial tone .Also ,due to the large power of the hilltop transmitter ,adjacent systems had to be several hundred kilometers apart to avoid interference . All in all ,the limited capacity made the system impractical.In VB6.0 MSChart controls is one function formidable high-level graph tool, has the rich graph plan function, may demonstrate two-dimensional and the three dimensional good chart, the linear chart, the cake chart and so on the many kinds of commonly used graph. Recently I in order to in double struck the graph when some region will the database content which corresponded with this region controlled on in DataGrid demonstrates, encountered many difficulties, finally used one to solve the problem from definition variable SelectSeries, concrete method as follows:Supposes the database name is " the student information ", has one Access table " the student result ", its content is one class student's test result, includes the student number, the name, the result 3 fields, the result field form is the character, the value is " is superior ", " is good ", " center ", " the difference " center one.Window Form1 includes one MSChart controls MC$score, the type for the two-dimensional cake chart, uses in to demonstrate each kind of result the student counts; One ADO controls AdScore uses in to connect the database; One DataGrid controls DgScore uses in by the form form demonstration database content.The work process is: Double strikes the cake chart some region, then DgScore demonstrates the corresponding result the student name list.Code as follows:Option ExplicitDim SelectedSeries as Integer ' from definition variable Dim Rs () as String ' withdraws the character string array which the record compendium uses Private Sub Form_Load ()' Establishes DataGrid controls the data pool DgScore.DataSource= " AdScore "' Establishes ADO controls the connection character string and the initial record source, namely demonstration content AdScore.ConnectString= " Provider=Microsoftc.oledb.3.51; Persist_Security Info=False; Data Source= student information "AdScore.RecordSource= " selet * from student result order by result "AdScore.Refresh' Supposes in advance withdraws the SQL sentence which the recording uses Rs (1) = " select * from the student result where result = " + Chr (34) + " is superior " + _Chr (34) + " order the by result "Rs (2) = " select * from the student result where result = " + Chr (34) + " is good " + _Chr (34) + " order the by result "Rs (3) = " select * from student result where result = " + Chr (34) + " center " + _Chr (34) + " order by result "Rs (4) = " select * from student result where result = " + Chr (34) + " difference " _Chr (34) + " order by result "End SubPrivate Sub MC$score_SeriesSelected (Series as Integer, MouseFlags as _Integer, Cancel as Integer)SelectedSeries=SeriesEnd SubPrivate Sub MC$score_PointSelected (Series as Integer, DataPoint as_Integer, MouseFlags asInteger, Cancel as Integer)SelectedSeries=SeriesEnd SubPrivate Sub MC$score_Db1Click ()' Changes ADO controls the record source and renovates Adoc1.RecordSource=Rs (SeletedSeries)Adoc1.RefreshEnd Sub---- VB does for the rapid application development (RAD) the tool more and more obtains the development personnel's approval and accepts. It to many API (for example ODBC API, SOCKET API and so on) the seal causes the programming to change is simple. At the same time, it supports under the integrated development environment visible, the event actuates, to be object-oriented and so on the programming characteristic. Under, we chat in VB transfer the memory process the realization method and its the matters needing attention.---- We know, the VB database programming has permits the many kinds of method, for instance straight takes over the use of ODBC the API programming, this method is flexible, is highly effective, the programmer may realize to the database complex control; Also may use in VB the data object, like RDO (long-distance data object), DAO (data visit object), ADO (ActiveX data object), this method realizes conveniently, quickly, but flexible worse somewhat. As a result of memory process in realization data merit and so on seal, hideaway as well as code pre- translation, reduced network load, maintenance convenience, therefore does by many RDBMS and the programming tool the support. In VB each 类数 also provides to saves the process according to the object the support.---- We as regularly explain its realization take ADO the step ---- 1. Foundation, debugging memory process. You may also be allowed to hang the procedure in the database outside other under the support carry on the memory process the foundation and the debugging work. In this example memory process code is as follows (uses in PUBS MS SQL the example storehouse):CREATE PROCEDURE myprocedure@job_id smallint,@job_lvl tinyintASSELECT *FROM employeeWHERE job_id < @job_idAND job_lvl > @job_lvl---- 2. Produces one new project in VB, the project has one window, one COMMAND (NAME: COMMAND1) button, one MSFlexGrid (NAME: MSFlexGrid1) controls.---- 3. The foundation connects ADO connection;---- 4. The foundation orders ADO command;---- 5. The foundation parameter and establishes each parameter the attribute;---- 6. Carries out ADO command;---- 7. The logarithm according to carries on processing; MSFlexGrid demonstrates inquires data ---- 8. The release connects, withdrawal procedure.---- Code as follows:States below the variable in the window:Dim cnn1 As ADODB.Connection ' connects Dim mycommand As ADODB.Command ' orders Dim parm_jobid As ADODB.Parameter ' parameter 1Dim parm_joblvl As ADODB.Parameter ' parameter 2Dim rstByQuery As ADODB.Recordset ' result collection Dim strCnn As String ' connection character string Joins the following code in the window LOAD event:Set cnn1 = New ADODB.Connection' Produces one connects strCnn = \ " DSN=MYDSN; uid=sa; pwd=\ "' Foundation system data pool MYDSN aims at the PUBS database cnn1.Open strCnn ' opens connects Joins the code as follows in window UNLOAD:cnn1.Close ' the closure connects Set cnn1 = Nothing ' the release connects In button code as follows:Dim i As integerDim j as integerSet parm_jobid = New ADODB.ParameterSet mycommand = New ADODB.Command\' parm_jobid.Name = \ " name1\ "this line can be ommitedparm_jobid.Type = adInteger '

编程工具的角色跟计算机硬件一起在过去45年中已经逐步形成。 编程语言今天，例如Visual Basic，从仅仅几年以前的编程语言非常不同。 与几年以前有货相比，Windows操作系统的视觉性质需要更先进的工具。 在有窗的环境之前，编程语言是你写计划用的一件简单的基于文本的工具。 今天你需要非常不仅仅是的一种语言； 你需要一种图表的开发工具， 能在窗口系统里面工作并且创建利用全部图解，多媒体的应用，在线，以及Windows 提供的multiprocessed 活动。 Visual Basic是这样的一件工具。 更多比语言, Visual.basic 让您引起与每个今天窗口操作系统相处融洽的方面的应用。 Visual.basic 5 进来三个味道: 标准版, 专业编辑, 并且企业版。 虽然这本书主要应付专业编辑, 标准版称学习的编辑和提供最少昂贵的方法对使用Visual.basic 。标准版给您完全开发环境, 编程语言, 并且许多同样用工具加工另一编辑提议。 如果您使用标准版, 您有一个强有力的程序设计工具。 某些人民显现出只以标准版和从未需要别的。虽然这条路线瞄准专业编辑为击中共同基础, 您能实际上运用整个24 小时路线如果您使用标准版; 您将发现另外的工具在这条路线甚而不得到的标准版。

CS方向sci三区的一个小刊，之前也是major revision，大四毕业了才中了。。所以在我心目中MV几乎约等于AC，虽然这辈子只投过一篇文章。北京译顶科技做的不错，可以联系他们一下 统一查下。

翻译的不好，仅供参考编程工具这个角色随着硬件有45年的发展了，今天的一门编程语言，象VB,与几年前的编程语言有很大不同。WINDOWS操作系统需求的可视话性工具比起几年前要求更高。在窗口环境之前，一门编程语言是一个简单的基于文字的随你写的程序的工具。今天你需要更多的不仅仅是一门语言。你需要一个图形化的可以工作在WINDOWS系统下和建立利用WINDOWS提供的所有的图形，多媒体，在线，和多线程处理等的应用程序的开发工具。VB就是这样一个工具，更好的一门语言，VB让你产生与今天的操作系统全面融合的应用程序。VB5流行3中风格：标准版本，个性化版本，和被叫做学习版本和用VB做的预定的最少开销编辑的标准版本。标准版本给你一个完整的开发环境，编程环境，和很多的类似其他编辑器提供的工具。如果你用标准版本，那你有一个强大的编程工具。尽管个性化版本的目标是力图找出共同点，但有些人开发只在标准版本下而永远也不用其他。如果你用标准版本你将利用事实上的整个24小时的课程。你会发现附加的工具在课程不连贯没有接触标准版本下。