如何编程取得注册表的网卡MTU值？

Question

如果找不到MTU值则新建一个新的MTU值
参考：
（1）、运行regedit   
    
  （2）、浏览到：   
    
  　　HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces   
    
    
    
  （3）、Interfaces下有多个子项，每个子项对应一个网卡。请按如下方法选择网卡：   
    
  　　（a）确定本机用来连接Internet的网卡或拨号连接的IP，如192.168.0.19；   
    
  　　（b）用鼠标点击Interfaces上的子项，查看键值列表中的IPAddress项；   
    
  　　（c）如果IPAddress的键值与（a）中的IP相同，即192.168.0.19，则该子项就是要找的网卡。   
    
  （4）、进入该子项，在右边的窗口里按鼠标右键，选择“新建”->“双字节值”，输入名称“MTU”，按回车。再用鼠标双击“MTU”，填入MTU的值。填写前请先把基数设为十进制。 
请问如何实现，哪个有代码贴出来参考下，谢了

Answer 1

uses
  Registry;var
  RegKey : TRegistry;
begin
  RegKey := TRegistry.Create;
  RegKey.RootKey := HKEY_LOCAL_MACHINE;
  if RegKey.OpenKey('\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces',True) then
  begin
    RegKey.WriteString('MTU','192.168.0.19');
    RegKey.CloseKey
  end;
    RegKey.Free;
end;具体的细节,你可以自己加

Answer 2

uses
  Registry;var
  RegKey : TRegistry;
begin
  RegKey := TRegistry.Create;
  RegKey.RootKey := HKEY_LOCAL_MACHINE;
  if RegKey.OpenKey('\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces',True) then
  begin
    RegKey.WriteString('MTU','192.168.0.19');
    RegKey.CloseKey
  end;
    RegKey.Free;
end;具体的细节,你可以自己加

Answer 3

注册表里是没有'192.168.0.19'这个子项的，注册表是这样：
\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{98FC92C6-1556-4893-A6A9-8335ABB2099D}
关健是怎么样通过本地网卡找到这个{98FC92C6-1556-4893-A6A9-8335ABB2099D}才能在它下面进行操作啊

Answer 4

你要去循环Interfaces下的子节点,然后和自己网卡作比较,相同即找到

Answer 5

procedure SetMtu(IP: String) ;
type
     TNetTransportEnum = function(pszServer : PWideChar; 
                                  Level : DWORD; 
                                  var pbBuffer : pointer; 
                                  PrefMaxLen : LongInt;
                                  var EntriesRead : DWORD; 
                                  var TotalEntries : DWORD; 
                                  var ResumeHandle : DWORD) : DWORD; stdcall;      TNetApiBufferFree = function(Buffer : pointer) : DWORD; stdcall;      PTransportInfo = ^TTransportInfo;
     TTransportInfo = record
                       quality_of_service : DWORD; 
                       number_of_vcs : DWORD; 
                       transport_name : PWChar; 
                       transport_address : PWChar;
                       wan_ish : boolean; 
                     end; 
type
  TaPInAddr = array[0..10] of PInAddr;
  PaPInAddr = ^TaPInAddr;
var
  HostName:   array [0..MAX_PATH] of char;
  NameLen:    Integer;
  WSData:     TWSAData;
  lpHostEnt:  PHostEnt;
  pptr:       PaPInAddr;
var E,ResumeHandle,
    EntriesRead,
    TotalEntries : DWORD;
    FLibHandle : THandle;
    sMachineName: String;
    pBuffer : pointer;
    pInfo : PTransportInfo;
    FNetTransportEnum : TNetTransportEnum;
    FNetApiBufferFree : TNetApiBufferFree;
    pszServer : array[0..128] of WideChar;
    i : integer;    Reg: TRegistry;
    strGUID: String;
    iPos0,iPos1: Integer;
begin 
  sMachineName := '\\127.0.0.1';
  // Setup and load from DLL 
  pBuffer := nil; 
  ResumeHandle := 0; 
  FLibHandle := LoadLibrary('NETAPI32.DLL');  // Execute the external function 
  if FLibHandle <> 0 then begin 
    @FNetTransportEnum := GetProcAddress(FLibHandle,'NetWkstaTransportEnum');
    @FNetApiBufferFree := GetProcAddress(FLibHandle,'NetApiBufferFree');
    E := FNetTransportEnum(StringToWideChar(sMachineName,pszServer,129),0,
                           pBuffer,-1,EntriesRead,TotalEntries,Resumehandle);    if E = 0 then begin 
      pInfo := pBuffer; 
      if WSAStartup(MakeWord(2,0), WSData) <> 0 then Exit;
      try
        NameLen := sizeof(HostName);
        fillchar(HostName, NameLen, 0);
        NameLen := GetHostName(HostName, NameLen);
        if NameLen = SOCKET_ERROR then Exit;
        lpHostEnt := GetHostByName(HostName);
        if lpHostEnt = Nil then Exit;
        I := 0;
        pPtr := PaPInAddr(lpHostEnt^.h_addr_list);
        while pPtr^[I] <> nil  do
          begin          // Enumerate all protocols - look for TCPIP
            inc(pInfo); 
            if pos('TCPIP',UpperCase(pInfo^.transport_name)) <> 0 then begin
              if inet_ntoa(pptr^[I]^) = IP then
                begin
                  Reg := TRegistry.Create;
                  try
                    Reg.RootKey := HKEY_LOCAL_MACHINE;
                    iPos0 := Pos('{',pInfo^.transport_name);
                    iPos1 := Pos('}',pInfo^.transport_name);
                    strGUID := Copy(pInfo^.transport_name, iPos0 ,iPos1 - iPos0 + 1);
                    if Reg.OpenKey('SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\'+ strGUID,false) then
                      begin
                        if Reg.ValueExists('MTU') then
                          ShowMessage(Format('IP地址:%s的MTU值为%d',[IP,reg.ReadInteger('MTU')]))
                        else begin
                          ShowMessage(Format('IP地址:%s的MTU值未设置！',[IP]));
                          //设置MTU值为1500
                          Reg.WriteInteger('MTU',1500);                        end;
                        Reg.CloseKey;
                      end;
                  finally
                    Reg.Free;
                  end;
                end;
            end;            
            Inc(I);
          end;
        
      finally
        WSACleanup;
      end;
      if pBuffer <> nil then FNetApiBufferFree(pBuffer);
    end;     try 
      FreeLibrary(FLibHandle); 
    except 
      // 错误处理
    end;
  end;
end;