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[RS485/232]Delphi调用API函数操作串口

nicebaby  发表于 2008/10/30 20:01:17  置顶    981 查看 0 回复  [上一主题]  [下一主题]

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再贴上一段用API操作串口的代码,还是API好,一目了然,呵呵。
unit main;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, ExtCtrls;

type
TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Memo1: TMemo;
    Memo2: TMemo;
    Label1: TLabel;
    Label2: TLabel;
    RadioGroup1: TRadioGroup;
    Button3: TButton;
    Button4: TButton;
    procedure Button1Click(Sender: TObject);
    procedure OpenSerialPort;
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
private
    { Private declarations }
public
    { Public declarations }
end;

var
Form1: TForm1;
hSerialPort:Cardinal;
implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
OpenSerialPort;
end;
procedure tform1.OpenSerialPort;
var
cc:TCommConfig;
Temp:string;

begin
Temp:='Com'+inttostr(RadioGroup1.ItemIndex+1);
hSerialPort:=CreateFile(PChar(Temp),GENERIC_READ or GENERIC_WRITE,0,nil,OPEN_EXISTING,0,0);
if (hSerialPort=invalid_handle_value) then
begin
    MessageBox(0,'打开串口失败','',MB_OK);
    Exit;
end;
GetCommState(hSerialPort,cc.dcb);
cc.dcb.BaudRate:=CBR_9600;
cc.dcb.ByteSize:=8;
cc.dcb.Parity:=NOPARITY;
cc.dcb.StopBits:=ONESTOPBIT;
if not SetCommState(hSerialPort,cc.dcb) then
begin
    ShowMessage('不能设置串口');
    CloseHandle(hSerialPort);
    Exit;
end
else
     ShowMessage('打开,并设置成功!');
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
if hSerialPort<>0 then CloseHandle(hSerialPort);
Exit;
end;

procedure TForm1.Button3Click(Sender: TObject);
var
temp:string;
lw:LongWord;
begin
if hSerialPort=0 then Exit;
temp:=Memo1.Text;
WriteFile(hSerialPort,PChar(temp)^,Length(temp),lw,nil);
end;

procedure TForm1.Button4Click(Sender: TObject);
var
tempString:string;
inBuff:array[0..2047]of Char;
bytesRead,dwError:LongWord;
cs:TComStat;
begin
ClearCommError(hSerialPort,dwError,@cs);
if cs.cbInQue>SizeOf(inBuff)then
begin
    PurgeComm(hSerialPort,PURGE_RXCLEAR);
    Exit;
end;
ReadFile(hSerialPort,inBuff,cs.cbInQue,bytesRead,nil);
tempString:=Copy(inBuff,1,cs.cbInQue);
Memo2.Text:=tempString;
end;

end.

测试软件代码下载:http://www.promcu.com/onews.asp?/123.html

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