怎样直接从缓存读取图片的,不必再次下载

Question

用WebBrowser打开网页后，然后提取里面图片链链接，然后用WebClient保存，怎样直接从缓存读取图片的,不必再次下载？

Answer 1

http://www.dotnetspider.com/qa/Question16777.aspx
How to access Temporary Internet Files to get a file 
http://www.codeproject.com/csharp/ponta.asp

Answer 2

ref:
http://www.codeproject.com/csharp/WebCacheTool.asp

Answer 3

参考
http://www.codeproject.com/csharp/WebCacheTool.asp?df=100&forumid=272203&exp=0&select=1416696

Answer 4

[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Auto)]   
public struct INTERNET_CACHE_ENTRY_INFO   
{  
public int dwStructSize;    
public IntPtr lpszSourceUrlName;    
public IntPtr lpszLocalFileName;    
public int CacheEntryType;    
public int dwUseCount;    
public int dwHitRate;    
public int dwSizeLow;    
public int dwSizeHigh;    
public FILETIME LastModifiedTime;    
public FILETIME ExpireTime;    
public FILETIME LastAccessTime;    
public FILETIME LastSyncTime;    
public IntPtr lpHeaderInfo;    
public int dwHeaderInfoSize;    
public IntPtr lpszFileExtension;    
public int dwExemptDelta;   
} [DllImport("wininet.dll", SetLastError=true, CharSet=CharSet.Auto)]  
public static extern IntPtr FindFirstUrlCacheEntry([MarshalAs(UnmanagedType.LPTStr)] string UrlSearchPattern, IntPtr lpFirstCacheEntryInfo, ref int lpdwFirstCacheEntryInfoBufferSize);  [DllImport("wininet.dll", SetLastError=true, CharSet=CharSet.Auto)]   
public static extern bool GetUrlCacheEntryInfo([MarshalAs(UnmanagedType.LPTStr)] string lpszUrlName,   IntPtr lpCacheEntryInfo,   ref int lpdwCacheEntryInfoBufferSize   );

//获取url对应cache文件
public static string GetCatchFileName(string url)
{
int nNeeded = 0;
FindFirstUrlCacheEntry(null, IntPtr.Zero, ref nNeeded);
IntPtr buf = Marshal.AllocHGlobal(nNeeded);
try
{
GetUrlCacheEntryInfo(url, buf, ref nNeeded);
INTERNET_CACHE_ENTRY_INFO CacheItem = (INTERNET_CACHE_ENTRY_INFO)Marshal.PtrToStructure(buf, typeof(INTERNET_CACHE_ENTRY_INFO));
return Marshal.PtrToStringAuto(CacheItem.lpszLocalFileName);
}
finally
{
Marshal.FreeHGlobal(buf);
}
}

Answer 5

先多谢net_lover，Knight94，lookfeng,fengyeng
先看看资料。

Answer 6

http://www.codeproject.com/csharp/WebCacheTool.asp