procedure EnumComPorts(Ports: TStrings); //自动获取com口函数
var
KeyHandle: HKEY;
ErrCode, Index: Integer;
ValueName, Data: string;
ValueLen, DataLen, ValueType: DWORD;
TmpPorts: TStringList;
begin
ErrCode := RegOpenKeyEx(
HKEY_LOCAL_MACHINE,
'HARDWARE\DEVICEMAP\SERIALCOMM',
0,
KEY_READ,
KeyHandle);

if ErrCode <> ERROR_SUCCESS then
Exit; // raise EComPort.Create(CError_RegError, ErrCode);

TmpPorts := TStringList.Create;
try
Index := 0;
repeat
ValueLen := 256;
DataLen := 256;
SetLength(ValueName, ValueLen);
SetLength(Data, DataLen);
ErrCode := RegEnumValue(
KeyHandle,
Index,
PChar(ValueName),
Cardinal(ValueLen),
nil,
@ValueType,
PByte(PChar(Data)),
@DataLen);

if ErrCode = ERROR_SUCCESS then
begin
SetLength(Data, DataLen);
TmpPorts.Add(Data);
Inc(Index);
end
else
if ErrCode <> ERROR_NO_MORE_ITEMS then
exit; //raise EComPort.Create(CError_RegError, ErrCode);

until (ErrCode <> ERROR_SUCCESS) ;

TmpPorts.Sort;
Ports.Assign(TmpPorts);
finally
RegCloseKey(KeyHandle);
TmpPorts.Free;
end;

end;

procedure TForm1.FormCreate(Sender: TObject);
begin
EnumComPorts(COMBOBOX1.Items); //得到串口列表
end;