我要使用.NET以及所有相关的酷炫功能，但我对用户控件和JS包含的效率感到疑惑。
我的用户控件主要由ascx显示页面和后面的.vb.ascx代码组成，这与.NET的代码隐藏编码风格一样，这对于简单编码非常有用，尽管它实际上是双倍的需要的文件。但是，据我所知，服务器会编译这些并有效地返回HTML。
控件需要JavaScript，正如我正在开发的那样，我为每个用户控件创建具有相同名称的外部JS文件，因此用户控件包含'controlName.ascx，controlName.vb.ascx，controlName.js “
如果用户请求的页面包含多个用户控件，浏览器将请求多个JS文件，可能是主页JS文件，jQuery和各个控件的每个所需文件。
这种方法在开发过程中对我有意义，因为所有内容都保持良好和整洁，使问题解决变得容易，但是当它上线时，浏览器会有大量的get请求，因为每次浏览器获得文件，甚至是请求文件检查其缓存是否必须花费一些时间的过程。
我最好将我的JS内联包含在ascx文件中，或代码隐藏，直接插入脚本，或者处理这些多个文件的“正确”方法是什么，以减少来自浏览器的get请求。
我出于同样的原因使用CSS sprites按钮和东西，所以想知道如何处理JS文件。在我的例子中，CSS通常由主页面中的类处理，因此这些都不是问题。
答案 0 :(得分：0)
我们实际上在ScriptManager之上构建了一个控件，它自动从页面上的所有控件中提取所有j，包括scriptresource.axd，并将它们存储在一个缓存文件中。由于它是自动化的，因此大大提高了性能并减少了维护工作。我们从.Net 2.0开始构建这个，所以我不确定ScriptManager现在是否提供相同的功能，但我认为值得一提。
以下是我们对此类的实现：
Option Explicit On
Option Strict On
Imports System.Collections.Generic
Imports System.Web.SessionState
Public Class OurScriptManager
Inherits ScriptManager
Implements IRequiresSessionState
Private m_ScriptBuilder As New StringBuilder
'Private m_sSessionIndex As String = ""
Private m_cScripts As List(Of ScriptReference)
Private m_fIsCached As Boolean
Private m_sScriptName As String = ""
Private m_sScriptFileName As String = ""
Const CACHED_SCRIPTS_DIR As String = "/scriptcache/"
Public Sub New()
' default constructor
End Sub
Public Property ScriptName() As String
Get
Return m_sScriptName
End Get
Set(ByVal value As String)
m_sScriptName = value
End Set
End Property
Private ReadOnly Property ScriptFileName() As String
Get
If String.IsNullOrEmpty(m_sScriptFileName) Then
m_sScriptFileName = "~" & CACHED_SCRIPTS_DIR & Me.ScriptName & ".js"
End If
Return m_sScriptFileName
End Get
End Property
Protected Overrides Sub OnInit(ByVal e As System.EventArgs)
' Exceptions are handled by the caller
MyBase.OnInit(e)
If String.IsNullOrEmpty(Me.ScriptName) Then
Me.ScriptName = Me.Page.ToString
End If
' this compiled script should be cached on the server
' check for the file, if it exists, load that file instead of generating it
If Configuration.HasPageScriptBeenCached(Me.ScriptFileName) AndAlso File.Exists(Me.Page.Server.MapPath(Me.ScriptFileName)) Then
m_fIsCached = True
Else
m_cScripts = New List(Of ScriptReference)
End If
End Sub
Protected Overrides Sub OnResolveScriptReference(ByVal e As System.Web.UI.ScriptReferenceEventArgs)
Try
MyBase.OnResolveScriptReference(e)
If Not m_fIsCached Then
' First, check to make sure this script should be loaded
Dim fIsFound As Boolean
For Each oXref As ScriptReference In m_cScripts
If oXref.Assembly = e.Script.Assembly AndAlso oXref.Name = e.Script.Name AndAlso oXref.Path = e.Script.Path Then
fIsFound = True
Exit For
End If
Next
' If this script is found within the list of scripts that this page uses, add the script to the scripthandler.aspx js output
If Not fIsFound Then
Dim oReference As ScriptReference
Dim oElement As ScriptReference
Dim fIsPathBased As Boolean
oElement = e.Script
If String.IsNullOrEmpty(oElement.Path) AndAlso Not String.IsNullOrEmpty(oElement.Name) AndAlso String.IsNullOrEmpty(oElement.Assembly) Then
' If resource belongs to System.Web.Extensions.dll, it does not
' provide assembly info that's why hard-coded assembly name is
' written to get it in profiler
oElement.Assembly = "System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"
End If
'check to see what type of script this is
If Not String.IsNullOrEmpty(oElement.Path) Then
' this script is a physical file
oReference = New ScriptReference(oElement.Path)
fIsPathBased = True
ElseIf Not String.IsNullOrEmpty(oElement.Assembly) AndAlso Not String.IsNullOrEmpty(oElement.Name) Then
' this script is generated by an assembly
oReference = New ScriptReference(oElement.Name, oElement.Assembly)
Else
' Couldn't find script, so bail to allow standard processing to take place.
Return
End If
If Not fIsPathBased Then
Dim sUrl As String
Dim oRequest As HttpRequest
Dim sScriptResourcePath As String
sUrl = GetUrl(oReference)
sScriptResourcePath = String.Format("{0}{1}{2}{3}{4}{5}{6}{7}", Context.Request.Url.Scheme, "://", Context.Request.Url.Host, ":", Context.Request.Url.Port, "/", Context.Request.ApplicationPath, "/ScriptResource.axd")
oRequest = New HttpRequest("scriptresource.axd", sScriptResourcePath, sUrl.Substring(sUrl.IndexOf("?"c) + 1))
Try
Using oWriter As New StringWriter(m_ScriptBuilder)
Dim oHandler As IHttpHandler = New System.Web.Handlers.ScriptResourceHandler
oHandler.ProcessRequest(New HttpContext(oRequest, New HttpResponse(oWriter)))
End Using
Catch theException As Exception
Call ReportError(theException)
' Since we couldn't automatically process this, just bail so that standard processing takes over
Return
End Try
Else
' If this script is from a file, open the file and load the
' contents of the file into the compiled js variable
Dim sAbsolutePath As String
sAbsolutePath = Context.Server.MapPath(oElement.Path)
Try
If System.IO.File.Exists(sAbsolutePath) Then
Using oReader As New StreamReader(sAbsolutePath, True)
m_ScriptBuilder.Append(oReader.ReadToEnd())
End Using
Else
Throw New Exception("File " & sAbsolutePath & " does not exist")
End If
Catch theException As Exception
Call ReportError(theException, New ExtraErrorInformation("File", sAbsolutePath))
' Since we couldn't automatically process this, just bail so that standard processing takes over
Return
End Try
End If
m_ScriptBuilder.AppendLine()
' add this script to the script reference library
Dim oNewElement As New ScriptReference
oNewElement.Name = e.Script.Name.ToString()
oNewElement.Assembly = e.Script.Assembly.ToString()
oNewElement.Path = e.Script.Path.ToString()
m_cScripts.Add(oNewElement)
End If
End If
' a script filename is provided for caching
e.Script.Assembly = String.Empty
e.Script.Name = String.Empty
e.Script.Path = Me.ScriptFileName
Catch theException As Exception
HttpContext.Current.Response.Write(ReportError(theException))
HttpContext.Current.Response.End()
End Try
End Sub
Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
' Exceptions are handled by the caller
MyBase.Render(writer)
If Not m_fIsCached Then
If Not String.IsNullOrEmpty(Me.ScriptName) Then
' Save script to file for caching
Using fsFile As New FileStream(Me.Page.Server.MapPath(Me.ScriptFileName), FileMode.Create, FileAccess.Write, FileShare.Read)
Using oWriter As New StreamWriter(fsFile)
oWriter.Write(m_ScriptBuilder.ToString)
oWriter.Flush()
oWriter.Close()
End Using
fsFile.Close()
End Using
' Record that the script file has been cached
Configuration.RecordPageScriptCached(Me.ScriptFileName)
End If
m_ScriptBuilder = Nothing
End If
End Sub
Private Function GetUrl(ByVal oReference As ScriptReference) As String
' Exceptions are handled by the caller
If String.IsNullOrEmpty(oReference.Path) Then
Try
Dim oMethod As MethodInfo
oMethod = oReference.GetType.GetMethod("GetUrl", BindingFlags.NonPublic Or BindingFlags.Instance)
If oMethod IsNot Nothing Then
Return DirectCast(oMethod.Invoke(oReference, New Object() {Me, False}), String)
Else
Return String.Empty
End If
Catch ex As Exception
Return String.Empty
End Try
Else
Return Me.ResolveClientUrl(oReference.Path)
End If
End Function
End Class
在上面的代码中，ReportError将异常记录到事件日志和/或文件中;您可以用自己的机制替换它。
以下是配置代码：
Private Shared m_cCachedPageScripts As Collections.Generic.List(Of String)
''' <summary>
''' This method is used to determine whether or not the script for the page has been cached.
''' This is used for script combining.
''' </summary>
''' <param name="sKey"></param>
''' <returns></returns>
''' <remarks></remarks>
Public Shared Function HasPageScriptBeenCached(ByVal sKey As String) As Boolean
' Exceptions are handled by the caller
SyncLock CacheSyncObject
If m_cCachedPageScripts IsNot Nothing AndAlso m_cCachedPageScripts.Contains(sKey) Then
Return True
End If
End SyncLock
End Function
''' <summary>
''' This method is used to record the fact that the page script has been cached.
''' This is used for script combining.
''' </summary>
''' <param name="sKey"></param>
''' <remarks></remarks>
Public Shared Sub RecordPageScriptCached(ByVal sKey As String)
' Exceptions are handled by the caller
SyncLock CacheSyncObject
If m_cCachedPageScripts Is Nothing Then
m_cCachedPageScripts.Add(sKey)
End If
m_cCachedPageScripts.Add(sKey)
End SyncLock
End Sub