C'è un modo per svuotare la cache DNS da un'app WPF C#? (su XP, Vista, Win7)

Question

C'è un modo per svuotare la cache DNS da un'app WPF C#? L'applicazione sarebbe in esecuzione su XP, Vista o Windows 7.

Answer 1

Questa potrebbe essere la soluzione del povero uomo, ma è possibile utilizzare System.Diagnostics.Process per avviare ipconfig /flushdns.

Answer 2

È possibile utilizzare una funzione da "dnsapi.dll" di Microsoft. Questo ti permetterà di farlo in modo completamente programmatico:

using System.Runtime.InteropServices; 

[DllImport("dnsapi.dll",EntryPoint="DnsFlushResolverCache")] 
private static extern UInt32 DnsFlushResolverCache(); 

public static void FlushMyCache() //This can be named whatever name you want and is the function you will call 
{ 
    UInt32 result = DnsFlushResolverCache(); 
} 

Ho provato questo e funziona benissimo.

Answer 3

Prova questo -

System.Diagnostics.Process process = new System.Diagnostics.Process(); 
System.Diagnostics.ProcessStartInfo startInfo = new System.Diagnostics.ProcessStartInfo(); 
startInfo.WindowStyle = System.Diagnostics.ProcessWindowStyle.Hidden; 
startInfo.FileName = "cmd.exe"; 
startInfo.Arguments = "/C ipconfig /flushdns"; 
process.StartInfo = startInfo; 
process.Start(); 

Answer 4

ho cercato su internet e non potrebbe trovare via per irrigare una sola voce DNS. Lavorando su qualcosa per fallire nel backup del data center questo è necessario per me. Ho dissimulato DnsFlushResolverCacheEntry_W e ho trovato il p/invoke sig di seguito. Io uso il metodo DnsQuery con il flag QueryNoWireFlag e NoHostFile. Se ci sono dei risultati, chiamo lo DnsFlushResolverCacheEntry_W. Questo potrebbe essere buone informazioni per qualcuno in futuro cercando di fare lo stesso

/// <summary> 
     /// Removes all related DNS records for the given hostname from the DNS resolver cache. 
     /// </summary> 
     /// <param name="hostName">The host name to flush from the resolver cache.</param> 
     /// <returns>Returns 1 if successful, zero if failed. No other error information is returned.</returns> 
     /// <remarks> 
     /// DnsFlushResolverCacheEntry_W is an undocumented method. From dissembler this method has two possible 
     /// return values 0 or 1. If the argument is null or the _R_ResolverFlushCacheEntry returns something 
     /// other than zero than the return value is zero. When _R_ResolverFlushCacheEntry returns zero the 
     /// return value is 1. Based off this and testing of the method it is assumed that 1 is used to indicate success. 
     /// After calling this method querying the DNS resolver cache returns no results. 
     /// 
     /// __stdcall DnsFlushResolverCacheEntry_W(x) 
     /// .... 
     /// 6DC12729 xor  esi, esi      // Zero esi 
     /// 6DC1272B cmp  [ebp+arg_0], esi    // check if the hostname is null 
     /// 6DC1272E jz  loc_6DC1D8B8     // Jump to end, return value is 0. 
     /// 6DC12734 mov  [ebp+ms_exc.registration.TryLevel], esi 
     /// 6DC12737 push esi       // Push 3 args for method, 2nd is hostname, others null 
     /// 6DC12738 push [ebp+arg_0] 
     /// 6DC1273B push esi 
     /// 6DC1273C call _R_ResolverFlushCacheEntry@12 // call this method 
     /// 6DC12741 mov  [ebp+var_1C], eax    // store return value in local 
     /// 6DC12744 mov  [ebp+ms_exc.registration.TryLevel], 0FFFFFFFEh 
     /// 6DC1274B 
     /// 6DC1274B loc_6DC1274B:       
     /// 6DC1274B cmp  [ebp+var_1C], esi   
     /// 6DC1274E jnz  loc_6DC1D8E7     // Error? jump to block that does etw then return 0 
     /// 6DC12754 xor  eax, eax      // Success? Set eax to zero 
     /// 6DC12756 inc  eax       // result is 0, increment by 1. success return value is 1 
     /// 6DC12757 call __SEH_epilog4 
     /// 6DC1275C retn 4 
     /// 
     /// 6DC1D8B8 xor  eax, eax      // set return value to zero 
     /// 6DC1D8BA jmp  loc_6DC12757     // jump to end 
     /// 
     /// 6DC1D8E7 mov  eax, _WPP_GLOBAL_Control 
     /// 6DC1D8EC cmp  eax, offset _WPP_GLOBAL_Control 
     /// 6DC1D8F1 jz  short loc_6DC1D8B8 
     /// 6DC1D8F3 test byte ptr [eax+1Ch], 40h 
     /// 6DC1D8F7 jz  short loc_6DC1D8B8 // This is probably testing some flag that is used to indicate if ETW is enabled 
     /// 6DC1D8F9 push [ebp+var_1C] 
     /// 6DC1D8FC push offset dword_6DC22494 
     /// 6DC1D901 push 0Dh 
     /// 6DC1D903 push dword ptr [eax+14h] 
     /// 6DC1D906 push dword ptr [eax+10h] 
     /// 6DC1D909 call _WPP_SF_q@20 ; WPP_SF_q(x,x,x,x,x)  // This method does some ETW tracing 
     /// 6DC1D90E jmp  short loc_6DC1D8B8 
     /// </remarks> 
     [DllImport("dnsapi.dll", EntryPoint = "DnsFlushResolverCacheEntry_W", CharSet = CharSet.Unicode)] 
     public static extern int DnsFlushResolverCacheEntry(string hostName);