WebBrower的应用和功能扩展中的一些技术细节

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WebBrower的应用和功能扩展中的一些技术细节

2013年10月09日 ⁄ 综合 ⁄ 共 8650字 ⁄ 字号小中大 ⁄ 评论关闭

注意：我的理解和处理结果不一定正确。

n 如何判断URL字符串是否有效

A．
命名空间:Microsoft.IE
程序集:IEHost（在 iehost.dll 中）
Manager.IsValidURL(url)
B.
<DllImport("SHLWAPI", CharSet:=CharSet.Auto)> _
Private Shared Function UrlIs(ByVal pszUrl As String, ByVal Url_Is As URL_IS) As Boolean
End Function

Public Shared Function IsValidURL(ByVal pURL As String) As Boolean
Return UrlIs(pURL, URL_IS.URLIS_URL)
End Function

Friend Enum URL_IS
    URLIS_APPLIABLE = 4
    URLIS_DIRECTORY = 5
    URLIS_FILEURL = 3
    URLIS_HASQUERY = 6
    URLIS_NOHISTORY = 2
    URLIS_OPAQUE = 1
    URLIS_URL = 0
End Enum

n 如何预处理URL字符串

Public Shared Sub CheckUri(ByRef uri As String)
If uri Is Nothing Then uri = WebBrowserEx.DefaultUri

uri = uri.Trim
If uri = WebBrowserEx.DefaultUri Then Return

If IsValidUrl(uri) Then Return

Dim prefix As String

    If uri.StartsWith("//") OrElse Regex.IsMatch(uri, "^[A-Za-z]:") Then
        prefix = "file://"
    Else
        prefix = "http://"
    End If

    If IsValidUrl(prefix & uri) Then
        uri = prefix & uri
        Return
    End If

uri = WebBrowserEx.DefaultUri
End Sub

注:WebBrowserEx.DefaultUri为Const String = "about:blank"
注意：上面函数参数uri用ByRef定义，非ByVal

n 如何把URL已编码的字符串转换为解码的字符串

命名空间:System.Web
程序集:System.Web（在 system.web.dll 中）
HttpUtility.UrlDecode 方法

n 如何把URL字符串编码

命名空间:System.Web
程序集:System.Web（在 system.web.dll 中）
HttpUtility.UrlEncode 方法

n 如何取得url快捷方式的内容

Private Declare Function GetPrivateProfileStringA Lib "kernel32.dll" ( _
     ByVal lpApplicationName As String, _
     ByVal lpKeyName As String, _
     ByVal lpDefault As String, _
     ByVal lpReturnedString As System.Text.StringBuilder, _
     ByVal nSize As Integer, _
     ByVal lpFileName As String _
) As Integer

Public Shared Function GetInternalShortcutUrl(ByVal filename As String) As String
    Dim mResult As New System.Text.StringBuilder(" ", 260)
    GetPrivateProfileStringA("InternetShortcut", "URL", "", mResult, mResult.Capacity, filename)
    Return mResult.ToString
End Function

Public Shared Function GetInternalShortcutIconFile(ByVal filename As String) As String
    Dim mResult As New System.Text.StringBuilder(" ", 260)
    GetPrivateProfileStringA("InternetShortcut", "IconFile", "", mResult, mResult.Capacity, filename)
    Return mResult.ToString
End Function

n 如何建立url快捷方式

Private Declare Function WritePrivateProfileString Lib "kernel32" Alias "WritePrivateProfileStringA" ( _
    ByVal lpSectionName As String, _
    ByVal lpKeyName As String, _
    ByVal lpString As String, _
    ByVal lpFileName As String _
) As Boolean

Public Shared Function AddInternetShortcut(ByVal url As String, ByVal filename As String) As Boolean
    filename = filename.Trim
    If filename.ToLower.LastIndexOf(".url") = -1 Then filename &= ".url"
    Return WritePrivateProfileString("InternetShortcut", "URL", url, filename)
End Function

Public Shared Function AddInternetShortcut(ByVal url As String, ByVal path As String, ByVal name As String) As Boolean
Dim mFilename As String = My.Computer.FileSystem.CombinePath(path, name)
Return AddInternetShortcut(url, mFilename)
End Function

Public Shared Function AddInternetShortcut(ByVal url As String, ByVal specialfolder As System.Environment.SpecialFolder, ByVal name As String) As Boolean
Dim mPath As String = System.Environment.GetFolderPath(specialfolder)
Return AddInternetShortcut(url, mPath, name)
End Function

n 如何读取IE缓存内容

注：参考了Scott McMaster的代码，见
WebCacheTool: Manipulate the IE Browser Cache From the Command-Line

Imports System
Imports System.Runtime.InteropServices
Namespace LzmTW.uSystem.uWindows.Win32API
    Friend NotInheritable Class UnsafeNativeMethods
        Public Const ERROR_SUCCESS As Integer = 0
        Public Const ERROR_FILE_NOT_FOUND As Integer = 2
        Public Const ERROR_ACCESS_DENIED As Integer = 5
        Public Const ERROR_INSUFFICIENT_BUFFER As Integer = 122
        Public Const ERROR_NO_MORE_ITEMS As Integer = 259

        <StructLayout(LayoutKind.Sequential)> _
        Public Structure FILETIME
            Public dwLowDateTime As Integer
            Public dwHighDateTime As Integer
        End Structure

        <StructLayout(LayoutKind.Sequential)> _
        Public Structure SYSTEMTIME
            Public Year As Int16
            Public Month As Int16
            Public DayOfWeek As Int16
            Public Day As Int16
            Public Hour As Int16
            Public Minute As Int16
            Public Second As Int16
            Public Milliseconds As Int16
        End Structure

        <DllImport("Kernel32.dll", SetLastError:=True)> _
        Public Shared Function FileTimeToSystemTime(ByRef FileTime As FILETIME, ByRef SystemTime As SYSTEMTIME) As Integer
        End Function

        <DllImport("kernel32.dll", SetLastError:=True)> _
        Public Shared Function SystemTimeToTzSpecificLocalTime( _
            ByVal lpTimeZoneInformation As IntPtr, _
            ByRef lpUniversalTime As SYSTEMTIME, _
            ByRef lpLocalTime As SYSTEMTIME _
        ) As Integer
        End Function

        Public Shared Function FromFileTime(ByVal ft As UnsafeNativeMethods.FILETIME) As DateTime
            If ft.dwHighDateTime = Int32.MaxValue OrElse (ft.dwLowDateTime = 0 AndAlso ft.dwHighDateTime = 0) Then
                Return DateTime.MinValue
            End If
            Dim syst As UnsafeNativeMethods.SYSTEMTIME = New UnsafeNativeMethods.SYSTEMTIME
            Dim systLocal As UnsafeNativeMethods.SYSTEMTIME = New UnsafeNativeMethods.SYSTEMTIME
            If 0 = UnsafeNativeMethods.FileTimeToSystemTime(ft, syst) Then
                Throw New ApplicationException("Error calling FileTimeToSystemTime: " & Marshal.GetLastWin32Error)
            End If
            If 0 = UnsafeNativeMethods.SystemTimeToTzSpecificLocalTime(IntPtr.Zero, syst, systLocal) Then
                Throw New ApplicationException("Error calling SystemTimeToTzSpecificLocalTime: " & Marshal.GetLastWin32Error)
            End If
            Return New DateTime(systLocal.Year, systLocal.Month, systLocal.Day, systLocal.Hour, systLocal.Minute, systLocal.Second)
        End Function

        Public Shared Function ToStringFromFileTime(ByVal ft As UnsafeNativeMethods.FILETIME) As String
            Dim dt As DateTime = FromFileTime(ft)
            If dt = DateTime.MinValue Then
                Return ""
            End If
            Return dt.ToString
        End Function

        Private Sub New()
        End Sub
    End Class
End Namespace

Imports System
Imports System.Collections
Imports System.Runtime.InteropServices
Imports System.Text.RegularExpressions
Imports System.Diagnostics

Namespace LzmTW.uSystem.uWindows.Win32API

    Friend NotInheritable Class WinInetAPI
        <StructLayout(LayoutKind.Sequential)> _
        Public Structure INTERNET_CACHE_ENTRY_INFO
            Public dwStructSize As Integer
            Public lpszSourceUrlName As String
            Public lpszLocalFileName As String
            Public CacheEntryType As Integer
            Public dwUseCount As Integer
            Public dwHitRate As Integer
            Public dwSizeLow As Integer
            Public dwSizeHigh As Integer
            Public LastModifiedTime As UnsafeNativeMethods.FILETIME
            Public ExpireTime As UnsafeNativeMethods.FILETIME
            Public LastAccessTime As UnsafeNativeMethods.FILETIME
            Public LastSyncTime As UnsafeNativeMethods.FILETIME
            Public lpHeaderInfo As IntPtr
            Public dwHeaderInfoSize As Integer
            Public lpszFileExtension As String
            Public dwExemptDelta As Integer
        End Structure

        <DllImport("wininet.dll", SetLastError:=True)> _
        Private Shared Function FindCloseUrlCache(ByVal hEnumHandle As IntPtr) As Integer
        End Function

        <DllImport("wininet.dll", SetLastError:=True)> _
        Private Shared Function FindFirstUrlCacheEntry( _
            ByVal lpszUrlSearchPattern As String, _
            ByVal lpFirstCacheEntryInfo As IntPtr, _
            ByRef lpdwFirstCacheEntryInfoBufferSize As Integer _
        ) As IntPtr
        End Function

        <DllImport("wininet.dll", SetLastError:=True)> _
        Private Shared Function FindNextUrlCacheEntry( _
            ByVal hEnumHandle As IntPtr, _
            ByVal lpNextCacheEntryInfo As IntPtr, _
            ByRef lpdwNextCacheEntryInfoBufferSize As Integer _
        ) As Integer
        End Function

        <DllImport("wininet.dll", SetLastError:=True)> _
        Private Shared Function GetUrlCacheEntryInfo( _
            ByVal lpszUrlName As String, _
            ByVal lpCacheEntryInfo As IntPtr, _
            ByRef lpdwCacheEntryInfoBufferSize As Integer _
        ) As Boolean
        End Function