网络和通讯编程
来源：岁月联盟
编辑：exp
时间：2009-06-08
打开拨号连接 调用拨号网络里的拨号程序来连接：其中连接Internet为你创建的拨号程序名称
winexec(rundll32.exe rnaui.dll,RnaDial +连接Internet,9);
一个串口通讯的问题? Serial Port Communications?
问
I want to build a simple electrical controller which receives input from a
sensor through a comm port and either turns a power source(s) on or off
based upon this signal. I want this controller to be software in nature.
How do I communicate through the port and is it possible to discern changes
in voltage.
If not, what kind of signal must be input.
答
When you want to write and read only binary signals you can use the printer
parallel port. For that purpose the Port command is useful. In the below an
example of some D1 code used for bidirectional 2 wire bus communication (I2C).
BaseAddress is $278, $378 or $3BC, depending on the LPT port used for
communication.
There is a but. In D1 the port function was available but not documented. In
D2 and D3 it seems to have disappeared entirely (Please somebody correct me if
this is wrong).
We are using the parallel printer port with attached a small interface card
with some I/O buffering for control of RF modules. Could somebody indicate
whether the Port function still exist or what the alternative could be ?
regards,
Hans Brekelmans
PROCEDURE SetIICline(Terminal: IICterminalTypes; High: Boolean);
Var Count : Word;
CtrlAddress: word;
Begin { set iic line }
CtrlAddress:=BaseAddress+2;
Case Terminal of
SCL : if High then Port[CtrlAddress]:=$08 else Port[CtrlAddress]:=$00;
SDA : if NOT High then Port[BaseAddress]:=$80 else Port[BaseAddress]:=$00;
END;
For Count := 1 to ClockDelay do;
End; {SetIICline}
FUNCTION GetIICline(Terminal: IICterminalTypes): Boolean;
const SDA_IN=$80; { SDA: 25 pin #11, status, NOT BUSY, bit 7 }
SCL_IN=$08; { SCL: 25 pin #15, status, NOT Error, bit 3 }
var Count : Word;
ReadAddress: word;
Begin
ReadAddress:=BaseAddress+1;
CASE Terminal OF
SCL: GetIICline:=((Port[ReadAddress] AND SCL_IN) = SCL_IN);
SDA: GetIICline:=((Port[ReadAddress] AND SDA_IN) = SDA_IN); { read sda
pin }
END;
For Count := 1 to ClockDelay do;
End;
得到本机IP地址? How about using winsockets?
This code is untested and ugly.
program get_ip;
uses
winsock,sysutils;
VAR
ch : ARRAY[1..32] OF Char;
i : Integer;
WSData: TWSAData;
MyHost: PHostEnt;
begin
IF WSAstartup(2,wsdata)<>0 THEN
BEGIN
Writeln(cant start Winsock: Error ,WSAGetLastError);
Halt(2);
END;
try
IF getHostName(@ch[1],32)<>0 THEN
BEGIN
Writeln(getHostName failed);
Halt(3);
END;
except
Writeln(getHostName failed);
halt(3);
end;
MyHost:=GetHostByName(@ch[1]);
IF MyHost=NIL THEN
BEGIN
Writeln(GetHostName(+StrPas(@ch[1])+) failed : Error
+IntToStr(WSAGetLastError));
Halt(4);
END
ELSE
BEGIN
Write(address );
FOR i:=1 TO 4 DO
BEGIN
Write(Ord(MyHost.h_addr^[i-1]));
IF i<4 THEN
write(.)
ELSE
writeln;
END;
END;
end.
任何动态改变/添加网络设置中的 TCP/IP 的 DNS 地址例如，把 DNS Server的地址添加为192.0.0.1和192.1.1.0，可调用：
SetTCPIPDNSAddresses(192.0.0.1 192.1.1.0) ;
// 各地址之间用一个空格隔开
1. SetTCPIPDNSAddresses 定义如下：
procedure SetTCPIPDNSAddresses( sIPs : string );
begin
//
// if using Windows NT
//
SaveStringToRegistry_LOCAL_MACHINE(
SYSTEMCurrentControlSet +
ServicesTcpipParameters,
NameServer,
sIPs );
//
// if using Windows 95
//
SaveStringToRegistry_LOCAL_MACHINE(
SYSTEMCurrentControlSet +
ServicesVxDMSTCP,
NameServer,
sIPs );
end;
2. 其中 SaveStringToRegistry_LOCAL_MACHINE 定义：
uses Registry;
procedure SaveStringToRegistry_LOCAL_MACHINE(
sKey, sItem, sVal : string );
var
reg : TRegIniFile;
begin
reg := TRegIniFile.Create( );
reg.RootKey := HKEY_LOCAL_MACHINE;
reg.WriteString( sKey, sItem, sVal + #0 );
reg.Free;
end;
如何在程序中动态取得Win95/98的网络邻居中的工作组及计算机名?可参考下面代码，或许有所帮助：
procedure GetDomainList(TV:TTreeView);
var
a : Integer;
ErrCode : Integer;
NetRes : Array[0..1023] of TNetResource;
EnumHandle : THandle;
EnumEntries : DWord;
BufferSize : DWord;
s : string;
itm : TTreeNode;
begin
{ Start here }
try
With NetRes[0] do begin
dwScope :=RESOURCE_GLOBALNET;
dwType :=RESOURCETYPE_ANY;
dwDisplayType :=RESOURCEDISPLAYTYPE_DOMAIN;
dwUsage :=RESOURCEUSAGE_CONTAINER;
lpLocalName :=NIL;
lpRemoteName :=NIL;
lpComment :=NIL;
lpProvider :=NIL;
end;
{ get net root }
ErrCode:=WNetOpenEnum(
RESOURCE_GLOBALNET,
RESOURCETYPE_ANY,
RESOURCEUSAGE_CONTAINER,
@NetRes[0],
EnumHandle
);
If ErrCode=NO_ERROR then begin
EnumEntries:=1;
BufferSize:=SizeOf(NetRes);
ErrCode:=WNetEnumResource(
EnumHandle,
EnumEntries,
@NetRes[0],
BufferSize
);
WNetCloseEnum(EnumHandle);
ErrCode:=WNetOpenEnum(
RESOURCE_GLOBALNET,
RESOURCETYPE_ANY,
RESOURCEUSAGE_CONTAINER,
@NetRes[0],
EnumHandle
);
EnumEntries:=1024;
BufferSize:=SizeOf(NetRes);
ErrCode:=WNetEnumResource(
EnumHandle,
EnumEntries,
@NetRes[0],
BufferSize
);
IF ErrCode=No_Error then with TV do try
a:=0;
Items.BeginUpDate;
Items.Clear;
Itm:=Items.Add(TV.Selected,string(NetRes[0].lpProvider));
Itm.ImageIndex:=0;
Itm.SelectedIndex:=0;
{ get domains }
下面的一个单元定义了一个组件. TNetworkBrowser, 可以枚举hierachical树上所有
的网络资源. 实际上浏览是要花费很长时间的,这您可以通过在WINDOWS资源管理器
中打开"整个网络" 来比较一下. 如果你设置SCOPE属性 为nsContext , 你就可以看到
和网络邻居
