unit Unit1;
interface
usesWindows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,Dialogs, SPComm, StdCtrls, ComCtrls;
typeTForm1 = class(TForm)Edit1: TEdit;Button2: TButton;Memo1: TMemo;Button3: TButton;Button1: TButton;Label1: TLabel;Button4: TButton;Comm1: TComm;Edit2: TEdit;Button5: TButton;StatusBar1: TStatusBar;procedure Button2Click(Sender: TObject);procedure Button3Click(Sender: TObject);procedure Button1Click(Sender: TObject);procedure Button4Click(Sender: TObject);procedure Button5Click(Sender: TObject);procedure FormDestroy(Sender: TObject);private{ Private declarations }public{ Public declarations }end;varForm1: TForm1;
implementation
{$R *.dfm}
procedure TForm1.Button2Click(Sender: TObject);
varCommPort : string;hCommFile : THandle;hdcb:DCB;
begin
commport:=Edit1.Text;
hCommFile := CreateFile(PChar(CommPort),GENERIC_READ or GENERIC_WRITE,0,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);//打开端口失败的处理if hCommFile =INVALID_HANDLE_VALUE thenStatusbar1.SimpleText:='不能打开端口';GetCommState(hcommFile,hdcb);  //获取DCB结构信息
 Memo1.Clear;Memo1.Lines.Add('DCB结构大小是：'+IntToStr(hdcb.DCBlength)+#13#10+'波特率大小是： '+IntToStr(hdcb.BaudRate)+#13#10+'XON的临界值是：'+IntToStr(hdcb.XonLim)+#13#10+'XOFF的临界值是：'+IntToStr(hdcb.XoffLim)+#13#10+'字符位数是：'+IntToStr(hdcb.ByteSize)+#13#10+'奇偶检验位：'+IntToStr(hdcb.Parity)+#13#10+'停止位：'+IntToStr(hdcb.StopBits)+#13#10+'XON字符：'+hdcb.XonChar+#13#10+'XOFF字符：'+hdcb.XoffChar+#13#10+'奇偶错误代替字符：'+hdcb.ErrorChar+#13#10+'结束字符：'+hdcb.EofChar+#13#10+'时间字符：'+hdcb.EvtChar+#13#10);CloseHandle(hcommfile);//关闭端口句柄，否则重新执行程序时会调用空句柄，不能得到正确的参数值
end;
procedure TForm1.Button3Click(Sender: TObject);
varCommPort : string;hCommFile : THandle;Buffer : PCommConfig;size : DWORD;
beginCommPort := 'COM2';hCommFile := CreateFile(PChar(CommPort),GENERIC_WRITE,0,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);if hCommFile=INVALID_HANDLE_VALUE thenbeginStatusbar1.SimpleText:='不能打开 '+ CommPort;exit;end;GetMem(Buffer, sizeof(TCommConfig));GetCommConfig(hCommFile, Buffer^, size);FreeMem(Buffer, sizeof(TCommConfig));GetMem(Buffer, size);GetCommConfig(hCommFile, Buffer^, size);if CommConfigDialog(PChar(CommPort),Handle,Buffer^) = true thenSetCommConfig(hCommFile, Buffer^, size);FreeMem(Buffer, size);CloseHandle(hCommFile);
end;
procedure TForm1.Button1Click(Sender: TObject);
varsetComm : string;hsetFile : THandle;hsetdcb:DCB;
begin//设置断口信息
setcomm:=Edit1.Text;
hsetFile := CreateFile(PChar(setComm),GENERIC_READ or GENERIC_WRITE,0,nil,OPEN_EXISTING,FILE_ATTRIBUTE_NORMAL,0);//打开端口失败的处理if hsetFile =INVALID_HANDLE_VALUE thenStatusbar1.SimpleText:='不能打开端口';GetCommState(hsetFile,hsetdcb);hsetdcb.BaudRate:=2400;hsetdcb.StopBits:=2;hsetdcb.ByteSize:=4;SetCommState(hsetFile,hsetdcb);  //获取DCB结构信息closeHandle(hsetfile);           //关闭端口
end;
procedure TForm1.Button4Click(Sender: TObject);
begin
comm1.StopComm;    //先关闭端口
{设置一些必要的参数}
Comm1.CommName:=Edit1.Text;
Comm1.BaudRate:=9600;
Comm1.ByteSize:=_8;
Comm1.StopBits:=_1;
Comm1.Parity:=None;
Trycomm1.StartComm;    //打开端口
exceptraise Exception.create('打开端口'+comm1.CommName+'出错了');
end;Statusbar1.SimpleText:=Comm1.CommName+'打开了';Button5.Enabled:=True;
end;
procedure TForm1.Button5Click(Sender: TObject);
var str:string;count:WORD;
begin
str:=pchar(Edit2.Text);
count:=length(str);
If comm1.WriteCommData(pchar(str),count) ThenStatusbar1.SimpleText:='已经发送'+IntToStr(count)+'字符'ElseStatusbar1.SimpleText:='发送不成功';
end;
procedure TForm1.FormDestroy(Sender: TObject);
begin
Comm1.StopComm;  //关闭端口
end;
end.