【正文】 or example, if you display database data in a control that has view state enabled, you do not have to return to the database each time the page is posted back to the server. You can automatically preserve the data within the page39。s view state between form posts.Displaying and Hiding ContentXVIIIImagine that you are creating a form with an optional section. For example, imagine that you are creating an online tax form, and you want to display or hide a section that contains questions that apply only to married tax filers.Or, imagine that you want to add an additional help button to the tax form. You might want to hide or display detailed instructions for pleting form questions depending on a user39。s preferences.Finally, imagine that you want to break the tax form into multiple pages so that a person views only one part of the tax form at a time.In the following sections, you learn about the properties that you can use to hide and display controls in a form. You learn how to use the Visible and Enabled properties with individual controls and groups of controls to hide and display page content.Using the Visible and Enabled PropertiesEvery control, including both HTML and Web controls, has a Visible property that determines whether the control is rendered. When a control39。s Visible property has the value False, the control is not displayed on the page。 the control is not processed for either prerendering or rendering.Web controls (but not every HTML control) have an additional property named Enabled. When Enabled has the value False and you are using Inter Explorer version or higher, the control appears ghosted and no longer functions. When used with other browsers, such as Netscape Navigator, the control might not appear ghosted, but it does not function.Disabling View StateIn certain circumstances, you might want to disable view state for an individual control or for an page as a whole. For example, you might have a control that contains a lot of data (imagine a RadioButtonList control with 1,000 options). You might not want to load the data into the hidden __VIEWSTATE form field if you are worried that the form data would significantly slow down the rendering of the page.Using Rich ControlsIn the following sections, you learn how to use three of the more featurerich XIXcontrols in the framework. You learn how to use the Calendar control to display interactive calendars, the AdRotator control to display rotating banner advertisements, and the HTMLInputFile control to accept file uploads.XX目 錄1 緒論 ........................................................................................................................1 開(kāi)發(fā)背景 ..............................................................................................................1 系統(tǒng)開(kāi)發(fā)的意義 ..................................................................................................1 開(kāi)發(fā)者的主要工作 ..............................................................................................2 論文的組織結(jié)構(gòu) ..................................................................................................22 相關(guān)技術(shù)介紹 .....................................................................................................3 BREW SDK 介紹 .................................................................................................3 BREW 模擬器介紹 ..............................................................................................4 OOC 介紹 .............................................................................................................5 ClassInC.......................................................................................................5 AbstractInterfaceInC ...................................................................................53 手機(jī)電話簿的設(shè)計(jì)與實(shí)現(xiàn) ..............................................................................6 系統(tǒng)設(shè)計(jì) ..............................................................................................................6 系統(tǒng)設(shè)計(jì)任務(wù) ................................................................................................6 系統(tǒng)模塊設(shè)計(jì) ................................................................................................6 功能模塊設(shè)計(jì) ................................................................................................7 數(shù)據(jù)存儲(chǔ)結(jié)構(gòu) ......................................................................................................7 數(shù)據(jù)存儲(chǔ)結(jié)構(gòu) ................................................................................................7 數(shù)據(jù)庫(kù)結(jié)構(gòu)設(shè)計(jì) ............................................................................................7 系統(tǒng)實(shí)現(xiàn) ..............................................................................................................8 基本操作說(shuō)明 ................................................................................................8 重要模塊實(shí)現(xiàn)細(xì)節(jié) ........................................................................................84 測(cè)試 ......................................................................................................................10 軟件測(cè)試的目標(biāo) ................................................................................................10 測(cè)試計(jì)劃及執(zhí)行情況 ........................................................................................10 集成測(cè)試 ............................................................................................................10 測(cè)試評(píng)價(jià) ............................................................................................................105 結(jié)論 ......................................................................................................................11 總結(jié) ....................................................................................................................11XXI 體會(huì) .........................................................................................