ASP.NET中Dropdownlist控件的使用技巧与应用实例

作为今后Web应用开发的主流技术之一，ASP．NET为我们提供了为数众多的具有强大功能的内置控件，利用这些控件可以很方便的实现我们需要的功能。但是在不同的场合下人们对功能的需求是不同的，因此在熟悉ASP.NET各控件功能的同时，对控件使用技巧的掌握也是必不可少的。本文通过一个完整的实例详细介绍了DropDownList控件的联动技巧，并对联动过程中出现的问题给出相应的解决方法。     

ASP.NET中Dropdownlist控件的使用技巧与应用实例

作为今后Web应用开发的主流技术之一,ASP.NET为我们提供了为数众多的具有强大功能的内置控件,利用这些控件可以很方便的实现我们需要的功能。但是在不同的场合下人们对功能的需求是不同的,因此在熟悉ASP.NET各控件功能的同时,对控件使用技巧的掌握也是必不可少的。本文通过一个完整的实例详细介绍了DropDownList控件的联动技巧,并对联动过程中出现的问题给出相应的解决方法。     

基于ASP.NET的Web GIS数据库访问的实现

ASP．NET是微软推出的新一代动态网页技术，在ASP．NET中，对数据库的访问是通过ADO．NET来实现的，ADO．NET对象模型中的DataSet对象提供了一系列访问数据库的接口，因此利用ASP.NET提供的ADO．NET可方便地实现对GIS属性数据的访问；同时可利用ASP．NET提供的自定义控件的功能，通过定义一系列具有空间数据操作功能的地图控件、远程处理（．NET Remoting）技术与创建的地图服务（Map Service），实现对GIS空间数据的访问和显示。     

微软技术

微软公司正式发布了ASP．NET AJAX 1．0正式版!其中主要包含了2部分的内容:ASP．NET AJAX Exten- sions库和一组AJAX控件包。ASP．NET AJAX Extensions库在客户端提供了核心的JavaScript功能封装,能够对多种浏览器提供跨平台的AJAX功能支持,这样,     

ASP.NET进阶--网上调查表的制作

本文介绍了ASP．NET的HTML服务器端控件与Web控件的使用方法。重点讲解了用Visual Studio．NET2003实现一个网上调查的方法、思路和具体步骤。从而使读者对ASP．NET服务器控件有一个感性的认识。     

封面书摘

ASP．NET 2．0新服务、控件与功能概览2002年推出以来,ASP．NET一直是网络应用中的王牌标准。目前ASP．NET正努力减少70％代码量来完成同样的开发需求。ASP．NET 2．0的新变化将比传统ASP升级为ASP 1．x时的变化更加引人注目。以下是ASP．NET 2．0中一些新功能的简要介绍,以及特定领域内的深入探讨和重点方面的范例程序。     

基于ASP.NET的Web GIS数据库访问的实现

ASP.NET是微软推出的新一代动态网页技术,在ASP.NET中,对数据库的访问是通过ADO.NET来实现的,ADO.NET对象模型中的DataSet对象提供了一系列访问数据库的接口,因此利用ASP.NET提供的ADO.NET可方便地实现对GIS属性数据的访问;同时可利用ASP.NET提供的自定义控件的功能,通过定义一系列具有空间数据操作功能的地图控件、远程处理(.NET Remoting)技术与创建的地图服务(Map Service),实现对GIS空间数据的访问和显示。     

基于GridView控件仿Excel格式显示数据的网页制作

通过一个实用的网页实例,深入探讨了ASP.NET的GridView控件模仿Excel格式显示数据的网页制作思路与实现过程,介绍了GridView控件在冻结窗格、合并单元格、自动编号和自定义分页控件等功能的编程技巧。     

ASP.NET2.0开发中的认证和授权

几乎每个Web应用都会涉及针对不同的用户进行权限分配的工作,用户登录后根据不同的权限访问系统不同的资源和实现不同的功能。在ASP.NET2.0之前,我们需要自己开发这样的功能,但是在ASP.NET2.0中,随着成员（Mem-bership）服务和相关控件的推出,极大地减轻了相关工作的工作量。     

图书

这是第一本针对有经验的ASP．NET开发人员所编写的、用于实现自定义ASP．NETAJAX服务器控件的书籍。不同于其他ASP,NETAJAX图书,此书专注于服务器控件的开发以及在ASP．NET3．5AJAX中所展现出来的效率提升,并且探讨了如何在最新的Visual Studio2008中加快开发AJAX的特性。     

Translating user control availability into perception: the moderating role of prior experience

On a basic level, perception of user control over media content should be partially a function of control option availability. At the same time, prior user experience with control options should interact with control availability to produce joint effects on control perception. To assess these ideas, we present experimental data from 101 University students in the United States. Participants engaged a documentary in one of three ways: by simply watching the documentary, by watching the documentary with the option of using typical VCR-type controls (such as fast-forward or reverse), or by watching and having available both VCR-type controls and scene sequencing control. Data support our hypotheses. While there was a generally positive relationship between exposure to user control options and user control perception across all participants, those participants with relatively less prior experience with Internet-based applications demonstrated a somewhat different relationship between control availability and control perception.     

Web-Traveler Policies for Images on Social Networks

Images are one of the most popular type of contents shared on these sites. One of the most popular types of contents shared on these sites is image. Most of these networks offer some rudimentary forms of access controls such as allowing the users to choose who can view their profiles or the images uploaded by them. These controls however apply only in the perimeter of the users’ direct control such as desktops, profiles etc. Users have no control over their content once it is downloaded by others. In order to enable a user to truly maintain control over his content, new access control mechanisms must be designed so as to enable users to control their content even when managed by others. Towards fulfilling this gap, in this paper we propose the concept of “web-traveler policies”. Web-traveler policies allow the user to specify who can view, upload or download a given image within a social network. The unique, innovative feature of web-traveler policies is that they travel with the image, as long as it is hosted on the given social networking site. Additionally, we explore the possibility of extending these controls across different sites, by using the concept of mashups. In the paper we prove the feasibility of this approach, by implementing a working prototype of our approach on a real open source social network platform. We test the performance and scalability of such architecture under heavy user loads and also its resilience towards naïve attacks. This work is a first innovative step toward scalable systems for providing each user with a centralized system for his/her own content’s protection all over the web.     

Bandwidth management and congestion control framework of the broadband network architecture

In this paper we describe an integrated set of procedures for bandwidth management and congestion control in IBM's broadband network architecture for high speed networks. These controls operate at two different time scales, at the connection level and at the packet or cell level. Major connection level controls are path selection, admission control and bandwidth allocation. These controls are applied at the connection setup time and are based on the connection characterization and the network state at that time. Packet level controls are access control, traffic monitoring and intermediate node buffer management. Because of their smaller time scale, they do not rely on any feedback information from the network. The main focus of this paoer is to reconcile the different time scales of these controls, and define how they interplay to ensure proper network operation. The ideas presented in this paper are being implemented and deployed in several test-beds and field trials for experimental validation.     

Multi-agent cooperation for particle accelerator control

Quite exhaustive theoretical studies exist in DAI, but it seems that there is not enough feedback from practice. In this paper we present practical investigations for applying and justifying the theoretical DAI results in a real industrial controls environment, and, conversely, we discuss the theoretical aspects of practical findings in these applied investigations made for accelerator control and operation. The results presented here are partly based on the research carried out at CERN during the ESPRIT-II Project ARCHON™. A generalized hypothesis is introduced, based on a unified view of control, monitoring, diagnosis, maintenance and repair tasks leading to a general method of cooperation for expert systems by exchanging hypotheses and leads to a mapping of different tasks in accelerator control to cooperating agents. This has been tested for task and result-sharing cooperation scenarios and we also report on studies carried out in relation to accelerator timings and their diagnosis as well as the transformation of these systems into a multi-agent community. Generalized hypotheses also allow us to treat the repetitive diagnosis-recovery cycle as a task-sharing cooperation. Problems with such a loop or even recursive calls between the different agents are discussed.     

Algorithms for relaxed control problems with delay

Three convergent procedures are presented. These determine a minimizing point of a relaxed optimal control problem defined by delay-differential equations with the control restricted to a compact convex subset of ? ^m In the first of these procedures, a strong variational algorithm due to Virk (1985 a) is extended to relaxed controls. The second uses a steepest descent approach. It is shown that both these procedures generate accumulation controls satisfying first-order necessary conditions of optimality. In the third procedure, the relaxed controls generated at each iteration are approximated using ordinary controls. When this is done, we show that limit points satisfy optimality conditions to within delta. Numerical performances of all three algorithms are also presented.     

A comprehensive investigation on the relationship between information technology investments and firm diversification

This paper empirically investigates the role played by information technology in diversified firms by building a demand function for IT investments. First by reviewing the management literature, we briefly examine different types of diversification, including related diversification, unrelated diversification, and geographic diversification. After carefully developing the theoretical arguments we empirically test the relationship between IT investments and different types of diversification. We find that in general diversified firms demand more investments in information technology, but the positive relationship may also depend on the extent to which firms diversify. Our findings show that firms with diversified structures that increase the complexities of coordination and control, e.g. unrelated diversification or extensive geographic diversification, would face a lesser demand for IT investments because of the increased use of financial controls instead of strategic controls by these firms. Overall, we find that information technology can serve as an effective coordination and control mechanism for moderate levels of diversification whereas non-IT mechanisms for coordination and control becomes more suitable in a context of higher levels of diversification. The implications of these findings for research and practice are discussed.

在Matlab仿真平台中嵌入用户界面的方法

介绍了一种利用ActiveX控件开发用户界面并嵌入到Matlab仿真环境,以方便用户进行初值设定、实时传参以及试验过程控制的方法。首先介绍了ActiveX控件的特点及其优势,然后重点研究了ActiveX控件与Matlab的接口问题。在此基础上以Matlab／xPC实时仿真环境为例详细介绍了将ActiveX控件嵌入到Matlab仿真环境的实现过程。最后给出了这种技术在实际工程项目中的一个应用实例。     

ASP.NET中GridView读取Excel数据的实现

在ASP.NET网站建设中,我们经常需要从Excel表格中读取一些相应的信息在页面上来显示,提供给用户方便的查看,怎样实现这一功能呢?Visual Studio 2005中有诸多的用来显示数据的控件,如DataGrid、Repeater、GridView等,这些控件由于各自的特点、属性的不同,因而都有自己独特的应用领域。本文就如何使用GridView显示控件来实现从Excel表格中读取数据进行研究和实现。     

Motion control of drift-free, left-invariant systems on Lie groups

In this paper we address the constructive controllability problem for drift-free, left-invariant systems on finite-dimensional Lie groups with fewer controls than state dimension. We consider small (ϵ) amplitude, low-frequency, periodically time-varying controls and derive average solutions for system behavior. We show how the pth-order average formula can be used to construct open-loop controls for point-to-point maneuvering of systems which require up to (p-1) iterations of Lie brackets to satisfy the Lie algebra controllability rank condition. In the cases p=2,3, we give algorithms for constructing these controls as a function of structure constants that define the control authority, i.e., the actuator capability, of the system. The algorithms are based on a geometric interpretation of the average formulas and produce sinusoidal controls that solve the constructive controllability problem with O(ϵ^P) accuracy in general (exactly if the Lie algebra is nilpotent). The methodology is applicable to a variety of control problems and is illustrated for the motion control problem of an autonomous underwater vehicle with as few as three control inputs