詳解ASP.NET頁(yè)面生命周期
更新時(shí)間：2015年12月30日 17:19:25 作者：少林無(wú)名掃地僧
這篇文章主要為大家介紹了ASP.NET頁(yè)面生命周期，熟悉頁(yè)面生命周期非常重要，這樣我們才能在生命周期的合適階段編寫代碼,需要的朋友可以參考下
ASP.NET頁(yè)面運(yùn)行時(shí)候，頁(yè)面將經(jīng)歷一個(gè)生命周期，在生命周期中將執(zhí)行一系列的處理步驟。包括初始化、實(shí)例化控件、還原和維護(hù)狀態(tài)、運(yùn)行時(shí)間處理程序代碼以及進(jìn)行呈現(xiàn)。熟悉頁(yè)面生命周期非常重要，這樣我們才能在生命周期的合適階段編寫代碼。如果我們能在寫代碼的時(shí)候想著我們現(xiàn)在是在做生命周期的哪一步那將是非常好的。
幾個(gè)代表性的問(wèn)題
在開始的時(shí)候我們先思考幾個(gè)問(wèn)題，看看我們?cè)诿枋鐾觏?yè)面生命周期的時(shí)候，能不能回答上這幾個(gè)問(wèn)題
- 1.為什么在服務(wù)器端能通過(guò)this.textbox1.Text獲取到用戶提交過(guò)來(lái)的數(shù)據(jù)？
- 2.在Page_Load中Response.Write("hello")查看生成的html代碼原文件，hello在哪里？為什么？
- 3.有一個(gè)服務(wù)器端的按鈕，設(shè)置了點(diǎn)擊事件，該點(diǎn)擊事件什么時(shí)候執(zhí)行？是先執(zhí)行Page_Load事件還是先執(zhí)行點(diǎn)擊事件？
- 4.為什么在服務(wù)器端通過(guò)this.textbox1.Text設(shè)置值后，客戶端就能顯示出來(lái)？
了解ASP.NET請(qǐng)求管道、應(yīng)用程序生命周期、整體運(yùn)行機(jī)制童鞋可能知道，ASP.NET應(yīng)用程序周期中PreRequestHandlerExecute事件與PostRequestHandlerExecute事件之間就是我們的頁(yè)面生命周期了，對(duì)于aspx頁(yè)面就是一系列的打造頁(yè)面控件樹，觸發(fā)各種頁(yè)面時(shí)間，對(duì)于一般處理程序ashx就是直接執(zhí)行咱們開發(fā)者寫的ProcessRequest方法了，對(duì)于MVC應(yīng)用程序就是創(chuàng)建控制器工廠，創(chuàng)建控制器對(duì)象，調(diào)用Action那一套了。
下面主要講述的就是ASP.NET WebForm中的頁(yè)面的生命周期了。
我們用反編譯工具查看Page類的ProcessRequest方法可以看見先調(diào)用了FrameworkInitialize; FrameworkInitialize里面就是打造了頁(yè)面控件樹，然后調(diào)用了ProcessRequestMain，就開始了執(zhí)行整個(gè)頁(yè)面生命周期了（其實(shí)就是調(diào)用了一系列的事件方法）（可能部分圖看不見右邊，可在新標(biāo)簽頁(yè)中打開圖片）
1.打造頁(yè)面控件樹
FrameworkInitialize內(nèi)部調(diào)用了_buildControlTree（）方法
上圖中左邊是前臺(tái)頁(yè)面的代碼，右邊是對(duì)應(yīng) 生成的打造控件樹的代碼。中間截取的是生成表單那一部分的代碼。
下面看一張?jiān)韴D
瀏覽器的DOM樹是根據(jù)Html標(biāo)簽生成一個(gè)C語(yǔ)言的DOM樹，而ASP.NET服務(wù)器端是用C#打造的一個(gè)控件樹，也是按照DOM結(jié)構(gòu)打造的。本質(zhì)是一樣。服務(wù)器端所有東西都加到頁(yè)面對(duì)象的控件集合中去了。標(biāo)簽在服務(wù)器端有對(duì)應(yīng)的控件對(duì)象的時(shí)候就用控件對(duì)象，沒(méi)有的時(shí)候就使用LiteralControl進(jìn)行封裝。不管是服務(wù)器控件還是字符串標(biāo)簽（沒(méi)有runat="server"的標(biāo)簽）都以控件對(duì)象的方式存在前臺(tái)頁(yè)面類的控件集合里面。好處就是生成前臺(tái)頁(yè)面的html代碼的時(shí)候，只需要遍歷控件集合里面的每一個(gè)控件對(duì)象的RenderControl方法，每一個(gè)控件都會(huì)調(diào)用自己的Render方法生成對(duì)應(yīng)的Html字符串。那么所有控件的生成的html字符串就還原成一個(gè)頁(yè)面的html代碼了?！ ?/p>
2.觸發(fā)PerformPreInit事件
在所有初始化之前初始化了這個(gè)事件，這個(gè)事件主要是初始化了主題，初始化了母版頁(yè)
private void PerformPreInit()
{
this.OnPreInit(EventArgs.Empty);
this.InitializeThemes();
this.ApplyMasterPage();
this._preInitWorkComplete = true;
}
3.觸發(fā)InitRecursive事件
4.觸發(fā)LoadAllState()事件
加載頁(yè)面狀態(tài)解析ViewState，將頁(yè)面表單中的ViewState進(jìn)行反Base64編碼，反序列化，存在頁(yè)面的ViewState屬性中
5.觸發(fā)ProcessPostData(this._requestValueCollection, true)事件
private void ProcessPostData(NameValueCollection postData, bool fBeforeLoad)
{
if (this._changedPostDataConsumers == null)
{
this._changedPostDataConsumers = new ArrayList();
}
if (postData != null)
{
foreach (string str in postData)
{
if ((str != null) && !IsSystemPostField(str))
{
Control control = this.FindControl(str);
if (control == null)
{
if (fBeforeLoad)
{
if (this._leftoverPostData == null)
{
this._leftoverPostData = new NameValueCollection();
}
this._leftoverPostData.Add(str, null);
}
}
else
{
IPostBackDataHandler postBackDataHandler = control.PostBackDataHandler;
if (postBackDataHandler == null)
{
if (control.PostBackEventHandler != null)
{
this.RegisterRequiresRaiseEvent(control.PostBackEventHandler);
}
}
else
{
if (postBackDataHandler != null)
{
NameValueCollection postCollection = control.CalculateEffectiveValidateRequest() ? this._requestValueCollection : this._unvalidatedRequestValueCollection;
if (postBackDataHandler.LoadPostData(str, postCollection))
{
this._changedPostDataConsumers.Add(control);
}
}
if (this._controlsRequiringPostBack != null)
{
this._controlsRequiringPostBack.Remove(str);
}
}
}
}
}
}
ArrayList list = null;
if (this._controlsRequiringPostBack != null)
{
foreach (string str2 in this._controlsRequiringPostBack)
{
Control control2 = this.FindControl(str2);
if (control2 != null)
{
IPostBackDataHandler adapterInternal = control2.AdapterInternal as IPostBackDataHandler;
if (adapterInternal == null)
{
adapterInternal = control2 as IPostBackDataHandler;
}
if (adapterInternal == null)
{
object[] args = new object[] { str2 };
throw new HttpException(SR.GetString("Postback_ctrl_not_found", args));
}
NameValueCollection values2 = control2.CalculateEffectiveValidateRequest() ? this._requestValueCollection : this._unvalidatedRequestValueCollection;
if (adapterInternal.LoadPostData(str2, values2))
{
this._changedPostDataConsumers.Add(control2);
}
}
else if (fBeforeLoad)
{
if (list == null)
{
list = new ArrayList();
}
list.Add(str2);
}
}
this._controlsRequiringPostBack = list;
}
}
主要做了兩件事
1）將表單里提交過(guò)來(lái)的控件數(shù)據(jù)設(shè)置給頁(yè)面對(duì)象的控件樹中對(duì)應(yīng)控件的屬性（給前面打造的控件樹里面控件給值），這樣在服務(wù)器端就可以拿到客戶端輸入的值了。
2）將表單里面提交過(guò)來(lái)的值與ViewState中控件原來(lái)的值進(jìn)行比對(duì)，不同則表示要觸發(fā)該控件的Change 事件，則同時(shí)將該控件放到一個(gè)集合（看源碼其實(shí)就是changedPostDataConsumers）中。在后續(xù)執(zhí)行過(guò)程中遍歷改集合依次觸發(fā)對(duì)應(yīng)控件的Change事件。
6.觸發(fā)LoadRecursive()事件
大名鼎鼎的Page_Load就是在這里執(zhí)行的。不過(guò)是先執(zhí)行頁(yè)面本身的Load事件再執(zhí)行頁(yè)面控件的Load事件哦,這時(shí)候前面給控件賦的值,表單提交過(guò)來(lái)的數(shù)據(jù),ViewState等等都可以使用了，IsPostBack的原理就是判斷是否有name為__VIEWSTATE的數(shù)據(jù)提交過(guò)來(lái)
7.再次觸發(fā)ProcessPostData(this._leftoverPostData, false)事件
這個(gè)事件我在網(wǎng)上看了很多人說(shuō)是將第一次遺漏下來(lái)的，第一次執(zhí)行ProcessPostData沒(méi)有涉及到的控件進(jìn)行處理，但是并沒(méi)有說(shuō)明哪些遺漏下來(lái)了。為什么第一次沒(méi)處理了？ 最后Google查到是處理我們開發(fā)者在頁(yè)面的Page_Load方法中添加的控件。在Page_Load中我們可以自己創(chuàng)建控件對(duì)象加到頁(yè)面對(duì)應(yīng)的“C#DOM樹中“，如：在Page_Load中寫
TextBox txt = new TextBox();txt.ID ="myTxtBox";this.form1.Controls.Add(txt);
這就是把開發(fā)者自己創(chuàng)建的控件加在頁(yè)面的form1的表單中。當(dāng)然你也可以加上Change事件了創(chuàng)建控件的時(shí)候。執(zhí)行的還是上面那兩件事了。則回發(fā)的時(shí)候可以給開發(fā)者在Page_Lod中手動(dòng)創(chuàng)建的控件還原值。
8.觸發(fā)RaiseChangedEvents事件
循環(huán)遍歷changedPostDataConsumers集合中的所有控件，依次執(zhí)行控件的非點(diǎn)擊回傳事件，比如文本框的改變事件等
9.觸發(fā)RaisePostBackEvent(this._requestValueCollection)事件
執(zhí)行按鈕點(diǎn)擊回傳事件或者驗(yàn)證事件，如果有多個(gè)按鈕，根據(jù)回發(fā)過(guò)來(lái)的按鈕的 name來(lái)判斷觸發(fā)哪個(gè)按鈕的事件，或者觸發(fā)該控件的驗(yàn)證事件
10.觸發(fā)PerformPreRenderComplete事件
循環(huán)遍歷控件樹中所有的控件，根據(jù)每個(gè)控件生成對(duì)應(yīng)的Html代碼，把服務(wù)器控件渲染成普通的html控件。
11.觸發(fā)事件SaveAllState事件
將服務(wù)器端ViewState集合中的內(nèi)容（開發(fā)者自己加的數(shù)據(jù)或控件狀態(tài)信息等）序列化然后Base64編碼然后設(shè)置到客戶端隱藏域__ViewState中
12.RenderControl(this.CreateHtmlTextWriter(this.Response.Output))
把要發(fā)送到客戶端瀏覽器的內(nèi)容設(shè)置到Response.Output，應(yīng)用程序?qū)⑺l(fā)送 到客戶端瀏覽器。[/code]
看到這里不知道大家是否已經(jīng)可以清晰地回答開篇提到的幾個(gè)問(wèn)題了，其實(shí)就是這些事件執(zhí)行的先后順序，頁(yè)面生命周期了?！鼻叭酥矘?，后人乘涼了"
最后附上生命周期ProcessRequest源碼
private void ProcessRequestMain(bool includeStagesBeforeAsyncPoint, bool includeStagesAfterAsyncPoint)
{
try
{
HttpContext context = this.Context;
string str = null;
if (includeStagesBeforeAsyncPoint)
{
if (this.IsInAspCompatMode)
{
AspCompatApplicationStep.OnPageStartSessionObjects();
}
if (this.PageAdapter != null)
{
this._requestValueCollection = this.PageAdapter.DeterminePostBackMode();
if (this._requestValueCollection != null)
{
this._unvalidatedRequestValueCollection = this.PageAdapter.DeterminePostBackModeUnvalidated();
}
}
else
{
this._requestValueCollection = this.DeterminePostBackMode();
if (this._requestValueCollection != null)
{
this._unvalidatedRequestValueCollection = this.DeterminePostBackModeUnvalidated();
}
}
string callbackControlID = string.Empty;
if (this.DetermineIsExportingWebPart())
{
if (!RuntimeConfig.GetAppConfig().WebParts.EnableExport)
{
throw new InvalidOperationException(SR.GetString("WebPartExportHandler_DisabledExportHandler"));
}
str = this.Request.QueryString["webPart"];
if (string.IsNullOrEmpty(str))
{
throw new InvalidOperationException(SR.GetString("WebPartExportHandler_InvalidArgument"));
}
if (string.Equals(this.Request.QueryString["scope"], "shared", StringComparison.OrdinalIgnoreCase))
{
this._pageFlags.Set(4);
}
string str3 = this.Request.QueryString["query"];
if (str3 == null)
{
str3 = string.Empty;
}
this.Request.QueryStringText = str3;
context.Trace.IsEnabled = false;
}
if (this._requestValueCollection != null)
{
if (this._requestValueCollection["__VIEWSTATEENCRYPTED"] != null)
{
this.ContainsEncryptedViewState = true;
}
callbackControlID = this._requestValueCollection["__CALLBACKID"];
if ((callbackControlID != null) && (this._request.HttpVerb == HttpVerb.POST))
{
this._isCallback = true;
}
else if (!this.IsCrossPagePostBack)
{
VirtualPath path = null;
if (this._requestValueCollection["__PREVIOUSPAGE"] != null)
{
try
{
path = VirtualPath.CreateNonRelativeAllowNull(DecryptString(this._requestValueCollection["__PREVIOUSPAGE"], Purpose.WebForms_Page_PreviousPageID));
}
catch
{
this._pageFlags[8] = true;
}
if ((path != null) && (path != this.Request.CurrentExecutionFilePathObject))
{
this._pageFlags[8] = true;
this._previousPagePath = path;
}
}
}
}
if (this.MaintainScrollPositionOnPostBack)
{
this.LoadScrollPosition();
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreInit");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_INIT_ENTER, this._context.WorkerRequest);
}
this.PerformPreInit();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_INIT_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreInit");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin Init");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_INIT_ENTER, this._context.WorkerRequest);
}
this.InitRecursive(null);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_INIT_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Init");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin InitComplete");
}
this.OnInitComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End InitComplete");
}
if (this.IsPostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin LoadState");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_VIEWSTATE_ENTER, this._context.WorkerRequest);
}
this.LoadAllState();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_VIEWSTATE_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End LoadState");
this.Trace.Write("aspx.page", "Begin ProcessPostData");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_POSTDATA_ENTER, this._context.WorkerRequest);
}
this.ProcessPostData(this._requestValueCollection, true);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_POSTDATA_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End ProcessPostData");
}
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreLoad");
}
this.OnPreLoad(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreLoad");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin Load");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_ENTER, this._context.WorkerRequest);
}
this.LoadRecursive();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Load");
}
if (this.IsPostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin ProcessPostData Second Try");
}
this.ProcessPostData(this._leftoverPostData, false);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End ProcessPostData Second Try");
this.Trace.Write("aspx.page", "Begin Raise ChangedEvents");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_POST_DATA_CHANGED_ENTER, this._context.WorkerRequest);
}
this.RaiseChangedEvents();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_POST_DATA_CHANGED_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Raise ChangedEvents");
this.Trace.Write("aspx.page", "Begin Raise PostBackEvent");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RAISE_POSTBACK_ENTER, this._context.WorkerRequest);
}
this.RaisePostBackEvent(this._requestValueCollection);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RAISE_POSTBACK_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Raise PostBackEvent");
}
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin LoadComplete");
}
this.OnLoadComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End LoadComplete");
}
if (this.IsPostBack && this.IsCallback)
{
this.PrepareCallback(callbackControlID);
}
else if (!this.IsCrossPagePostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreRender");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_RENDER_ENTER, this._context.WorkerRequest);
}
this.PreRenderRecursiveInternal();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_RENDER_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreRender");
}
}
}
if ((this._legacyAsyncInfo == null) || this._legacyAsyncInfo.CallerIsBlocking)
{
this.ExecuteRegisteredAsyncTasks();
}
this.ValidateRawUrlIfRequired();
if (includeStagesAfterAsyncPoint)
{
if (this.IsCallback)
{
this.RenderCallback();
}
else if (!this.IsCrossPagePostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreRenderComplete");
}
this.PerformPreRenderComplete();
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreRenderComplete");
}
if (context.TraceIsEnabled)
{
this.BuildPageProfileTree(this.EnableViewState);
this.Trace.Write("aspx.page", "Begin SaveState");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_SAVE_VIEWSTATE_ENTER, this._context.WorkerRequest);
}
this.SaveAllState();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_SAVE_VIEWSTATE_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End SaveState");
this.Trace.Write("aspx.page", "Begin SaveStateComplete");
}
this.OnSaveStateComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End SaveStateComplete");
this.Trace.Write("aspx.page", "Begin Render");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RENDER_ENTER, this._context.WorkerRequest);
}
if (str != null)
{
this.ExportWebPart(str);
}
else
{
this.RenderControl(this.CreateHtmlTextWriter(this.Response.Output));
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RENDER_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Render");
}
this.CheckRemainingAsyncTasks(false);
}
}
}
catch (ThreadAbortException exception1)
{
HttpApplication.CancelModuleException exceptionState = exception1.ExceptionState as HttpApplication.CancelModuleException;
if ((((includeStagesBeforeAsyncPoint & includeStagesAfterAsyncPoint) && (this._context.Handler == this)) && ((this._context.ApplicationInstance != null) && (exceptionState != null))) && !exceptionState.Timeout)
{
this._context.ApplicationInstance.CompleteRequest();
ThreadResetAbortWithAssert();
}
else
{
this.CheckRemainingAsyncTasks(true);
throw;
}
}
catch (ConfigurationException)
{
throw;
}
catch (Exception exception2)
{
PerfCounters.IncrementCounter(AppPerfCounter.ERRORS_DURING_REQUEST);
PerfCounters.IncrementCounter(AppPerfCounter.ERRORS_TOTAL);
if (!this.HandleError(exception2))
{
throw;
}
}
}
private void ProcessRequestMain(bool includeStagesBeforeAsyncPoint, bool includeStagesAfterAsyncPoint)
{
try
{
HttpContext context = this.Context;
string str = null;
if (includeStagesBeforeAsyncPoint)
{
if (this.IsInAspCompatMode)
{
AspCompatApplicationStep.OnPageStartSessionObjects();
}
if (this.PageAdapter != null)
{
this._requestValueCollection = this.PageAdapter.DeterminePostBackMode();
if (this._requestValueCollection != null)
{
this._unvalidatedRequestValueCollection = this.PageAdapter.DeterminePostBackModeUnvalidated();
}
}
else
{
this._requestValueCollection = this.DeterminePostBackMode();
if (this._requestValueCollection != null)
{
this._unvalidatedRequestValueCollection = this.DeterminePostBackModeUnvalidated();
}
}
string callbackControlID = string.Empty;
if (this.DetermineIsExportingWebPart())
{
if (!RuntimeConfig.GetAppConfig().WebParts.EnableExport)
{
throw new InvalidOperationException(SR.GetString("WebPartExportHandler_DisabledExportHandler"));
}
str = this.Request.QueryString["webPart"];
if (string.IsNullOrEmpty(str))
{
throw new InvalidOperationException(SR.GetString("WebPartExportHandler_InvalidArgument"));
}
if (string.Equals(this.Request.QueryString["scope"], "shared", StringComparison.OrdinalIgnoreCase))
{
this._pageFlags.Set(4);
}
string str3 = this.Request.QueryString["query"];
if (str3 == null)
{
str3 = string.Empty;
}
this.Request.QueryStringText = str3;
context.Trace.IsEnabled = false;
}
if (this._requestValueCollection != null)
{
if (this._requestValueCollection["__VIEWSTATEENCRYPTED"] != null)
{
this.ContainsEncryptedViewState = true;
}
callbackControlID = this._requestValueCollection["__CALLBACKID"];
if ((callbackControlID != null) && (this._request.HttpVerb == HttpVerb.POST))
{
this._isCallback = true;
}
else if (!this.IsCrossPagePostBack)
{
VirtualPath path = null;
if (this._requestValueCollection["__PREVIOUSPAGE"] != null)
{
try
{
path = VirtualPath.CreateNonRelativeAllowNull(DecryptString(this._requestValueCollection["__PREVIOUSPAGE"], Purpose.WebForms_Page_PreviousPageID));
}
catch
{
this._pageFlags[8] = true;
}
if ((path != null) && (path != this.Request.CurrentExecutionFilePathObject))
{
this._pageFlags[8] = true;
this._previousPagePath = path;
}
}
}
}
if (this.MaintainScrollPositionOnPostBack)
{
this.LoadScrollPosition();
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreInit");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_INIT_ENTER, this._context.WorkerRequest);
}
this.PerformPreInit();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_INIT_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreInit");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin Init");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_INIT_ENTER, this._context.WorkerRequest);
}
this.InitRecursive(null);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_INIT_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Init");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin InitComplete");
}
this.OnInitComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End InitComplete");
}
if (this.IsPostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin LoadState");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_VIEWSTATE_ENTER, this._context.WorkerRequest);
}
this.LoadAllState();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_VIEWSTATE_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End LoadState");
this.Trace.Write("aspx.page", "Begin ProcessPostData");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_POSTDATA_ENTER, this._context.WorkerRequest);
}
this.ProcessPostData(this._requestValueCollection, true);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_POSTDATA_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End ProcessPostData");
}
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreLoad");
}
this.OnPreLoad(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreLoad");
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin Load");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_ENTER, this._context.WorkerRequest);
}
this.LoadRecursive();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_LOAD_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Load");
}
if (this.IsPostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin ProcessPostData Second Try");
}
this.ProcessPostData(this._leftoverPostData, false);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End ProcessPostData Second Try");
this.Trace.Write("aspx.page", "Begin Raise ChangedEvents");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_POST_DATA_CHANGED_ENTER, this._context.WorkerRequest);
}
this.RaiseChangedEvents();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_POST_DATA_CHANGED_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Raise ChangedEvents");
this.Trace.Write("aspx.page", "Begin Raise PostBackEvent");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RAISE_POSTBACK_ENTER, this._context.WorkerRequest);
}
this.RaisePostBackEvent(this._requestValueCollection);
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RAISE_POSTBACK_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Raise PostBackEvent");
}
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin LoadComplete");
}
this.OnLoadComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End LoadComplete");
}
if (this.IsPostBack && this.IsCallback)
{
this.PrepareCallback(callbackControlID);
}
else if (!this.IsCrossPagePostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreRender");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_RENDER_ENTER, this._context.WorkerRequest);
}
this.PreRenderRecursiveInternal();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_PRE_RENDER_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreRender");
}
}
}
if ((this._legacyAsyncInfo == null) || this._legacyAsyncInfo.CallerIsBlocking)
{
this.ExecuteRegisteredAsyncTasks();
}
this.ValidateRawUrlIfRequired();
if (includeStagesAfterAsyncPoint)
{
if (this.IsCallback)
{
this.RenderCallback();
}
else if (!this.IsCrossPagePostBack)
{
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "Begin PreRenderComplete");
}
this.PerformPreRenderComplete();
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End PreRenderComplete");
}
if (context.TraceIsEnabled)
{
this.BuildPageProfileTree(this.EnableViewState);
this.Trace.Write("aspx.page", "Begin SaveState");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_SAVE_VIEWSTATE_ENTER, this._context.WorkerRequest);
}
this.SaveAllState();
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_SAVE_VIEWSTATE_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End SaveState");
this.Trace.Write("aspx.page", "Begin SaveStateComplete");
}
this.OnSaveStateComplete(EventArgs.Empty);
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End SaveStateComplete");
this.Trace.Write("aspx.page", "Begin Render");
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RENDER_ENTER, this._context.WorkerRequest);
}
if (str != null)
{
this.ExportWebPart(str);
}
else
{
this.RenderControl(this.CreateHtmlTextWriter(this.Response.Output));
}
if (EtwTrace.IsTraceEnabled(5, 4))
{
EtwTrace.Trace(EtwTraceType.ETW_TYPE_PAGE_RENDER_LEAVE, this._context.WorkerRequest);
}
if (context.TraceIsEnabled)
{
this.Trace.Write("aspx.page", "End Render");
}
this.CheckRemainingAsyncTasks(false);
}
}
}
catch (ThreadAbortException exception1)
{
HttpApplication.CancelModuleException exceptionState = exception1.ExceptionState as HttpApplication.CancelModuleException;
if ((((includeStagesBeforeAsyncPoint & includeStagesAfterAsyncPoint) && (this._context.Handler == this)) && ((this._context.ApplicationInstance != null) && (exceptionState != null))) && !exceptionState.Timeout)
{
this._context.ApplicationInstance.CompleteRequest();
ThreadResetAbortWithAssert();
}
else
{
this.CheckRemainingAsyncTasks(true);
throw;
}
}
catch (ConfigurationException)
{
throw;
}
catch (Exception exception2)
{
PerfCounters.IncrementCounter(AppPerfCounter.ERRORS_DURING_REQUEST);
PerfCounters.IncrementCounter(AppPerfCounter.ERRORS_TOTAL);
if (!this.HandleError(exception2))
{
throw;
}
}
}
以上就是關(guān)于ASP.NET頁(yè)面生命周期的詳細(xì)內(nèi)容介紹，希望對(duì)大家的學(xué)習(xí)有所幫助。
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