Lm th? no ? xa b? nh? cache khi n c?a b?n lu tr? m?t i?u khi?n WebBrowser trong Visual C#.NET

D?ch tiu ? D?ch tiu ?
ID c?a bi: 326201 - Xem s?n ph?m m bi ny p d?ng vo.
Bung t?t c? | Thu g?n t?t c?

? Trang ny

TM T?T

Bi vi?t t?ng b?c ny m t? cch s? d?ng WinINet x? l? ?ng d?ng l?p tr?nh giao di?n (API) ch?c nng ? xa b? nh? cache tr?c ti?p.

B?n c th? ph?i xo b? nh? cache l?p tr?nh khi n c?a b?n lu tr? m?t i?u khi?n WebBrowser. Tuy nhin, tnh nng ny l khng c s?n thng qua giao di?n i?u khi?n WebBrowser.

Ch?c nng WinINet x? l?

? xa b? nh? cache tr?c ti?p, b?n c th? s? d?ng ch?c nng WinINet x? l? sau y:
  • S? d?ng cc FindFirstURLCacheEntry ch?c nng t?m th?y m?c nh?p ?u tin c?a b? nh? cache.
  • S? d?ng cc FindNextUrlCacheEntry ch?c nng ? k khai thng qua b? nh? cache.
  • S? d?ng cc DeleteUrlCacheEntry ch?c nng ? xa m?i m?c.
M?u m? trong bi vi?t ny s? d?ng t?t c? cc ch?c nng ny.

LU ?: Cc ch?c nng ny ch? c s?n v?i Microsoft Internet Explorer 5. V? v?y, b?n ph?i bao g?m ki?m tra thch h?p (trong bao g?m cc m?u m? trong bi vi?t ny) ? ngn ch?n l?i.

Cc b?c ? xa b? nh? Cache trong Visual C#.NET

S? d?ng ch?c nng WinINet x? l? trong Visual C#.NET ? xa t?t c? cc t?p tin trong b? nh? cache, h?y lm theo cc b?c sau:
  1. B?t ?u Microsoft Visual Studio.NET.
  2. Trn cc Tp tr?nh n, i?m ?n M?i, sau b?m D an.
  3. Trong cc D? n m?i h?p tho?i h?p, b?m vo Visual C# cc d? n d?i Cc lo?i d? n, sau b?m Giao di?n i?u khi?n ?ng d?ng d?i Khun mu.
  4. Thm m? sau vo cc l?p h?c Class1.cs:
    using System;
    using System.Runtime.InteropServices;
    
    // Visual C# version of Q326201
    namespace Q326201CS
    {
        // Class for deleting the cache.
        class DeleteCache
        {
            // For PInvoke: Contains information about an entry in the Internet cache
            [StructLayout(LayoutKind.Explicit, Size=80)]
            public struct INTERNET_CACHE_ENTRY_INFOA
            {
                [FieldOffset(0)]  public uint dwStructSize;
                [FieldOffset(4)]  public IntPtr lpszSourceUrlName;
                [FieldOffset(8)]  public IntPtr lpszLocalFileName;
                [FieldOffset(12)] public uint CacheEntryType;
                [FieldOffset(16)] public uint dwUseCount;
                [FieldOffset(20)] public uint dwHitRate;
                [FieldOffset(24)] public uint dwSizeLow;
                [FieldOffset(28)] public uint dwSizeHigh;
                [FieldOffset(32)] public FILETIME LastModifiedTime;
                [FieldOffset(40)] public FILETIME ExpireTime;
                [FieldOffset(48)] public FILETIME LastAccessTime;
                [FieldOffset(56)] public FILETIME LastSyncTime;
                [FieldOffset(64)] public IntPtr lpHeaderInfo;
                [FieldOffset(68)] public uint dwHeaderInfoSize;
                [FieldOffset(72)] public IntPtr lpszFileExtension;
                [FieldOffset(76)] public uint dwReserved;
                [FieldOffset(76)] public uint dwExemptDelta;
            }
    
            // For PInvoke: Initiates the enumeration of the cache groups in the Internet cache
            [DllImport(@"wininet",
                SetLastError=true,
                CharSet=CharSet.Auto,
                EntryPoint="FindFirstUrlCacheGroup",
                CallingConvention=CallingConvention.StdCall)]
            public static extern IntPtr FindFirstUrlCacheGroup(
                int dwFlags,
                int dwFilter,
                IntPtr lpSearchCondition,
                int dwSearchCondition,
                ref long lpGroupId,
                IntPtr lpReserved);
    
            // For PInvoke: Retrieves the next cache group in a cache group enumeration
            [DllImport(@"wininet",
                SetLastError=true,
                CharSet=CharSet.Auto,
                EntryPoint="FindNextUrlCacheGroup",
                CallingConvention=CallingConvention.StdCall)]
            public static extern bool FindNextUrlCacheGroup(
                IntPtr hFind,
                ref long lpGroupId,
                IntPtr lpReserved);
    
            // For PInvoke: Releases the specified GROUPID and any associated state in the cache index file
            [DllImport(@"wininet", 
                SetLastError=true, 
                CharSet=CharSet.Auto, 
                EntryPoint="DeleteUrlCacheGroup", 
                CallingConvention=CallingConvention.StdCall)]
            public static extern bool DeleteUrlCacheGroup(
                long GroupId,
                int dwFlags,
                IntPtr lpReserved);
    
            // For PInvoke: Begins the enumeration of the Internet cache
            [DllImport(@"wininet",
                SetLastError=true,
                CharSet=CharSet.Auto,
                EntryPoint="FindFirstUrlCacheEntryA",
                CallingConvention=CallingConvention.StdCall)]
            public static extern IntPtr FindFirstUrlCacheEntry(
                [MarshalAs(UnmanagedType.LPTStr)] string lpszUrlSearchPattern,
                IntPtr lpFirstCacheEntryInfo,
                ref int lpdwFirstCacheEntryInfoBufferSize);
    
            // For PInvoke: Retrieves the next entry in the Internet cache
            [DllImport(@"wininet",
                SetLastError=true,
                CharSet=CharSet.Auto,
                EntryPoint="FindNextUrlCacheEntryA",
                CallingConvention=CallingConvention.StdCall)]
            public static extern bool FindNextUrlCacheEntry(
                IntPtr hFind,
                IntPtr lpNextCacheEntryInfo,
                ref int lpdwNextCacheEntryInfoBufferSize);
    
            // For PInvoke: Removes the file that is associated with the source name from the cache, if the file exists
            [DllImport(@"wininet",
                SetLastError=true,
                CharSet=CharSet.Auto,
                EntryPoint="DeleteUrlCacheEntryA",
                CallingConvention=CallingConvention.StdCall)]
            public static extern bool DeleteUrlCacheEntry(
                IntPtr lpszUrlName);
    
            [STAThread]
            static void Main(string[] args)
            {
                // Indicates that all of the cache groups in the user's system should be enumerated
                const int CACHEGROUP_SEARCH_ALL = 0x0;
                // Indicates that all the cache entries that are associated with the cache group
                // should be deleted, unless the entry belongs to another cache group.
                const int CACHEGROUP_FLAG_FLUSHURL_ONDELETE = 0x2;
                // File not found.
                const int ERROR_FILE_NOT_FOUND = 0x2;
                // No more items have been found.
                const int ERROR_NO_MORE_ITEMS = 259;
                // Pointer to a GROUPID variable
                long groupId = 0;
    
                // Local variables
                int cacheEntryInfoBufferSizeInitial = 0;
                int cacheEntryInfoBufferSize = 0;
                IntPtr cacheEntryInfoBuffer = IntPtr.Zero;
                INTERNET_CACHE_ENTRY_INFOA internetCacheEntry;
                IntPtr enumHandle = IntPtr.Zero;
                bool returnValue = false;
    
                // Delete the groups first.
                // Groups may not always exist on the system.
                // For more information, visit the following Microsoft Web site:
                // http://msdn.microsoft.com/library/?url=/workshop/networking/wininet/overview/cache.asp			
                // By default, a URL does not belong to any group. Therefore, that cache may become
                // empty even when the CacheGroup APIs are not used because the existing URL does not belong to any group.			
                enumHandle = FindFirstUrlCacheGroup(0, CACHEGROUP_SEARCH_ALL, IntPtr.Zero, 0, ref groupId, IntPtr.Zero);
                // If there are no items in the Cache, you are finished.
                if (enumHandle != IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
                    return;
    
                // Loop through Cache Group, and then delete entries.
                while(true)
                {
                    // Delete a particular Cache Group.
                    returnValue = DeleteUrlCacheGroup(groupId, CACHEGROUP_FLAG_FLUSHURL_ONDELETE, IntPtr.Zero);
                    if (!returnValue && ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error())
                    {	
                        returnValue = FindNextUrlCacheGroup(enumHandle, ref groupId, IntPtr.Zero);
                    }
    
                    if (!returnValue && (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error() || ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error()))
                        break;
                }
    
                // Start to delete URLs that do not belong to any group.
                enumHandle = FindFirstUrlCacheEntry(null, IntPtr.Zero, ref cacheEntryInfoBufferSizeInitial);
                if (enumHandle == IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
                    return;
    
                cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
                cacheEntryInfoBuffer = Marshal.AllocHGlobal(cacheEntryInfoBufferSize);
                enumHandle = FindFirstUrlCacheEntry(null, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
    
                while(true)
                {
                    internetCacheEntry = (INTERNET_CACHE_ENTRY_INFOA)Marshal.PtrToStructure(cacheEntryInfoBuffer, typeof(INTERNET_CACHE_ENTRY_INFOA));		
    
                    cacheEntryInfoBufferSizeInitial = cacheEntryInfoBufferSize;
                    returnValue = DeleteUrlCacheEntry(internetCacheEntry.lpszSourceUrlName);				
                    if (!returnValue)
                    {	
                        returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
                    }
                    if (!returnValue && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
                    {
                        break;
                    }			
                    if (!returnValue && cacheEntryInfoBufferSizeInitial > cacheEntryInfoBufferSize)
                    {
                        cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
                        cacheEntryInfoBuffer = Marshal.ReAllocHGlobal(cacheEntryInfoBuffer, (IntPtr) cacheEntryInfoBufferSize);
                        returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);					
                    }
                }
                Marshal.FreeHGlobal(cacheEntryInfoBuffer);		
            }
        }
    }
    					
  5. Bin d?ch v sau ch?y cc d? n.
  6. ? xc nh?n r?ng cc t?p tin Internet t?m th?i trong b? nh? cache c?a b?n ? b? xo, h?y lm theo cc b?c trong Microsoft Internet Explorer:
    1. Trn cc Cng cu tr?nh n, nh?p vo Tuy chon Internet.
    2. Trong cc T?p Internet t?m th?i di?n tch vo cc T?ng qut tab, b?m vo Thit t.
    3. Nh?p vo Xem t?p. Nh?n th?y r?ng t?t c? cc t?p tin trong b? nh? cache Internet Explorer ? b? xa.

THAM KH?O

M?u m? trong bi vi?t ny s? d?ng cc Tng h khng gian tn l m?t ph?n c?a Visual Studio.NET runtime. ? bi?t thm chi ti?t, gh thm Web site sau c?a Microsoft Developer Network (MSDN):
Interoperating v?i khng ?c qu?n l? m?
http://msdn2.Microsoft.com/en-US/Library/sd10k43k (vs.71) .aspx
? bi?t thng tin v? Microsoft.NET pht tri?n, thm MSDN Web site sau:
.Trung tm nh pht tri?n NET Framework
http://msdn2.Microsoft.com/en-US/netframework/Default.aspx
? bi?t thm thng tin v? c php c?a ch?c nng b? nh? ?m WinInet, truy c?p MSDN Web site sau:
WinINet x? l? b? nh? ?m
http://msdn2.Microsoft.com/en-US/Library/ms965968.aspx
? bi?t thm thng tin, h?y b?m vao s? bi vi?t sau ? xem bi vi?t trong C s? Ki?n th?c Microsoft:
262110Lm th? no ? xa b? nh? cache khi n c?a b?n lu tr? m?t i?u khi?n WebBrowser
? bi?t thm chi ti?t v? pht tri?n gi?i php d?a trn Web cho Microsoft Internet Explorer, h?y truy c?p trang Web Microsoft sau y:
http://MSDN.Microsoft.com/IE/

http://support.Microsoft.com/IEP

Thu?c tnh

ID c?a bi: 326201 - L?n xem xt sau cng: 28 Thang Tam 2011 - Xem xt l?i: 2.0
p d?ng
  • Microsoft Visual C# .NET 2002 Standard Edition
T? kha:
kbcaching kbcominterop kbhowto kbhowtomaster kbwebbrowser kbwininet kbmt KB326201 KbMtvi
My d?ch
QUAN TRONG: Bi vi?t ny ?c d?ch b?ng ph?n m?m d?ch my c?a Microsoft ch? khng ph?i do con ng?i d?ch. Microsoft cung c?p cc bi vi?t do con ng?i d?ch v c? cc bi vi?t do my d?ch ? b?n c th? truy c?p vo t?t c? cc bi vi?t trong C s? Ki?n th?c c?a chng ti b?ng ngn ng? c?a b?n. Tuy nhin, bi vi?t do my d?ch khng ph?i lc no c?ng hon h?o. Lo?i bi vi?t ny c th? ch?a cc sai st v? t? v?ng, c php ho?c ng? php, gi?ng nh m?t ng?i n?c ngoi c th? m?c sai st khi ni ngn ng? c?a b?n. Microsoft khng ch?u trch nhi?m v? b?t k? s? thi?u chnh xc, sai st ho?c thi?t h?i no do vi?c d?ch sai n?i dung ho?c do ho?t ?ng s? d?ng c?a khch hng gy ra. Microsoft c?ng th?ng xuyn c?p nh?t ph?n m?m d?ch my ny.
Nh?p chu?t vo y ? xem b?n ti?ng Anh c?a bi vi?t ny:326201

Cung cp Phan hi

 

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