请教网络连接问题!很急 请教大家一个局域网连接问题?如何判断我机器是否与局域网中指定服务器连接呢?我用SCOCKET判断可以但很慢,请教有没有好的办法啊!多谢,在线等! 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 用ping命令首先,对编程中需要的动态链接库作一简要说明:在Windows的System目录下,你可以找到Icmp.dll文件,该动态链接库提供了ICMP协议的所有功能,我们的编程就建立在对该动态链接库的调用上。 Icmp.dll文件内的调用函数说明如下: 1、IcmpCreateFile 打开一个句柄,通过该句柄你可以发送ICMP的请求回送报文。 2、IcmpCloseHandle 关闭你通过IcmpCreateFile函数打开的句柄。 3、IcmpSendEcho 通过你打开的句柄发送ICMP请求,在超时或应答报文接收后返回。其参数基本上和它的帧结构一致,可参下面的程序部分,其具体含意你可以参看有关ICMP协议的书籍。 初步了解了上述的三个函数后,我们就可以开始编程了。 首先,我们的程序运行后应该有如图1所示的基本功能。例程运行示意图 然后,在程序的开始部分(FormCreate)对WinSocket进行初始化,其作用是申明使用的版本信息,同时调入Icmp.dll库。 type PIPOptionInformation = ^TIPOptionInformation; TIPOptionInformation = packed record TTL: Byte; TOS: Byte; Flags: Byte; OptionsSize: Byte; OptionsData: PChar; end; PIcmpEchoReply = ^TIcmpEchoReply; TIcmpEchoReply = packed record Address: DWORD; Status: DWORD; RTT: DWORD; DataSize: Word; Reserved: Word; Data: Pointer; Options: TIPOptionInformation; end; TIcmpCreateFile = function: THandle; stdcall; TIcmpCloseHandle = function(IcmpHandle: THandle): Boolean; stdcall; TIcmpSendEcho = function(IcmpHandle:THandle; DestinationAddress: DWORD; RequestData: Pointer; RequestSize: Word; RequestOptions: PIPOptionInformation; ReplyBuffer: Pointer; ReplySize: DWord; Timeout: DWord ): DWord; stdcall; TMyPing = class(TForm) Panel1: TPanel; Label1: TLabel; PingEdit: TEdit; ExeBtn: TButton; Button2: TButton; Button3: TButton; StatusShow: TMemo; procedure Button3Click(Sender: TObject); procedure FormCreate(Sender: TObject); procedure ExeBtnClick(Sender: TObject); private { Private declarations } hICMP: THANDLE; IcmpCreateFile : TIcmpCreateFile; IcmpCloseHandle: TIcmpCloseHandle; IcmpSendEcho: TIcmpSendEcho; public { Public declarations } end; procedure TMyPing.FormCreate(Sender: TObject); var WSAData: TWSAData; hICMPdll: HMODULE; begin WSAStartup($101, WSAData); // Load the icmp.dll stuff hICMPdll := LoadLibrary('icmp.dll'); @ICMPCreateFile := GetProcAddress(hICMPdll, 'IcmpCreateFile'); @IcmpCloseHandle := GetProcAddress(hICMPdll, 'IcmpCloseHandle'); @IcmpSendEcho := GetProcAddress(hICMPdll, 'IcmpSendEcho'); hICMP := IcmpCreateFile; StatusShow.Text := ''; StatusShow.Lines.Add('目的IP地址 字节数 返回时间(毫秒)'); end; 接下来,就要进行如下所示的Ping操作的实际编程过程了。 procedure TMyPing.ExeBtnClick(Sender: TObject); var IPOpt:TIPOptionInformation;// IP Options for packet to send FIPAddress:DWORD; pReqData,pRevData:PChar; pIPE:PIcmpEchoReply;// ICMP Echo reply buffer FSize: DWORD; MyString:string; FTimeOut:DWORD; BufferSize:DWORD; begin if PingEdit.Text < > '' then begin FIPAddress := inet_addr(PChar(PingEdit.Text)); FSize := 40; BufferSize := SizeOf(TICMPEchoReply) + FSize; GetMem(pRevData,FSize); GetMem(pIPE,BufferSize); FillChar(pIPE^, SizeOf(pIPE^), 0); pIPE^.Data := pRevData; MyString := 'Hello,World'; pReqData := PChar(MyString); FillChar(IPOpt, Sizeof(IPOpt), 0); IPOpt.TTL := 64; FTimeOut := 4000; IcmpSendEcho(hICMP, FIPAddress, pReqData, Length(MyString), @IPOpt, pIPE, BufferSize, FTimeOut); if pReqData^ = pIPE^.Options.OptionsData^ then begin StatusShow.Lines.Add(PChar(PingEdit.Text) + ' ' +IntToStr(pIPE^.DataSize) + ' ' +IntToStr(pIPE^.RTT)); end; FreeMem(pRevData); FreeMem(pIPE); end end; 晕了.再不解决就没饭碗了..救小弟一命!!! 请各位帮忙看看,小问题来的. 急!在线等待!!请教高手如何用流的方式导入导出excel 如何获得一幅图片有那些色彩值?? Sql Server 声称的*.sql文件在程序里如何用上? 控制打印机走纸??? 如果我要在dbgrid里面加一项合计,要求是把各个字段里面每个值的和都放入合计里面,请问这该怎么做??急!!! 简单的删除和查询,十万火急,做毕业设计! 求教关于cxgrid控件左右拖拉的问题 Delphi里如何跟踪调试DLL 关于报表的备注和显示内容如何放置的问题请教 为什么我的Unit不能够调试跟踪?
首先,对编程中需要的动态链接库作一简要说明:在Windows的System目录下,你可以找到Icmp.dll文件,该动态链接库提供了ICMP协议的所有功能,我们的编程就建立在对该动态链接库的调用上。
Icmp.dll文件内的调用函数说明如下:
1、IcmpCreateFile
打开一个句柄,通过该句柄你可以发送ICMP的请求回送报文。
2、IcmpCloseHandle
关闭你通过IcmpCreateFile函数打开的句柄。
3、IcmpSendEcho
通过你打开的句柄发送ICMP请求,在超时或应答报文接收后返回。其参数基本上和它的帧结构一致,可参下面的程序部分,其具体含意你可以参看有关ICMP协议的书籍。
初步了解了上述的三个函数后,我们就可以开始编程了。
首先,我们的程序运行后应该有如图1所示的基本功能。例程运行示意图
然后,在程序的开始部分(FormCreate)对WinSocket进行初始化,其作用是申明使用的版本信息,同时调入Icmp.dll库。
type
PIPOptionInformation = ^TIPOptionInformation;
TIPOptionInformation = packed record
TTL: Byte;
TOS: Byte;
Flags: Byte;
OptionsSize: Byte;
OptionsData: PChar;
end;
PIcmpEchoReply = ^TIcmpEchoReply;
TIcmpEchoReply = packed record
Address: DWORD;
Status: DWORD;
RTT: DWORD;
DataSize: Word;
Reserved: Word;
Data: Pointer;
Options: TIPOptionInformation;
end;
TIcmpCreateFile = function: THandle; stdcall;
TIcmpCloseHandle = function(IcmpHandle: THandle): Boolean; stdcall;
TIcmpSendEcho = function(IcmpHandle:THandle;
DestinationAddress: DWORD;
RequestData: Pointer;
RequestSize: Word;
RequestOptions: PIPOptionInformation;
ReplyBuffer: Pointer;
ReplySize: DWord;
Timeout: DWord
): DWord; stdcall;
TMyPing = class(TForm)
Panel1: TPanel;
Label1: TLabel;
PingEdit: TEdit;
ExeBtn: TButton;
Button2: TButton;
Button3: TButton;
StatusShow: TMemo;
procedure Button3Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure ExeBtnClick(Sender: TObject);
private
{ Private declarations }
hICMP: THANDLE;
IcmpCreateFile : TIcmpCreateFile;
IcmpCloseHandle: TIcmpCloseHandle;
IcmpSendEcho: TIcmpSendEcho;
public
{ Public declarations }
end;
procedure TMyPing.FormCreate(Sender: TObject);
var
WSAData: TWSAData;
hICMPdll: HMODULE;
begin
WSAStartup($101, WSAData);
// Load the icmp.dll stuff
hICMPdll := LoadLibrary('icmp.dll');
@ICMPCreateFile := GetProcAddress(hICMPdll, 'IcmpCreateFile');
@IcmpCloseHandle := GetProcAddress(hICMPdll, 'IcmpCloseHandle');
@IcmpSendEcho := GetProcAddress(hICMPdll, 'IcmpSendEcho');
hICMP := IcmpCreateFile;
StatusShow.Text := '';
StatusShow.Lines.Add('目的IP地址 字节数 返回时间(毫秒)');
end;
接下来,就要进行如下所示的Ping操作的实际编程过程了。
procedure TMyPing.ExeBtnClick(Sender: TObject);
var
IPOpt:TIPOptionInformation;// IP Options for packet to send
FIPAddress:DWORD;
pReqData,pRevData:PChar;
pIPE:PIcmpEchoReply;// ICMP Echo reply buffer
FSize: DWORD;
MyString:string;
FTimeOut:DWORD;
BufferSize:DWORD;
begin
if PingEdit.Text < > '' then
begin
FIPAddress := inet_addr(PChar(PingEdit.Text));
FSize := 40;
BufferSize := SizeOf(TICMPEchoReply) + FSize;
GetMem(pRevData,FSize);
GetMem(pIPE,BufferSize);
FillChar(pIPE^, SizeOf(pIPE^), 0);
pIPE^.Data := pRevData;
MyString := 'Hello,World';
pReqData := PChar(MyString);
FillChar(IPOpt, Sizeof(IPOpt), 0);
IPOpt.TTL := 64;
FTimeOut := 4000;
IcmpSendEcho(hICMP, FIPAddress, pReqData, Length(MyString), @IPOpt, pIPE, BufferSize, FTimeOut); if pReqData^ = pIPE^.Options.OptionsData^ then begin StatusShow.Lines.Add(PChar(PingEdit.Text) + ' ' +IntToStr(pIPE^.DataSize) + ' ' +IntToStr(pIPE^.RTT)); end; FreeMem(pRevData); FreeMem(pIPE); end end;