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windows下串口通信同步与异步方式

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  1. #include <iostream>
  2. #include <windows.h>
  3. #include <assert.h>
  4.  
  5. using namespace std;
  6.  
  7. HANDLE g_hCom = INVALID_HANDLE_VALUE;
  8. const unsigned MAX_BUF_LEN = 32;
  9. const char* const g_pData = "hello";
  10.  
  11.  
  12. DWORD WINAPI ThreadRead( LPVOID lpParameter )
  13. {
  14. 	char szBuf[ MAX_BUF_LEN ] = { 0 };
  15. 	DWORD dwRead;
  16. 	OVERLAPPED ov;
  17. 	memset( &ov, 0, sizeof( ov ) );
  18. 	ov.hEvent = CreateEvent( NULL, TRUE, TRUE, NULL );
  19. 	assert( ov.hEvent );
  20.  
  21. 	if( !ReadFile( g_hCom, szBuf, strlen( g_pData ), &dwRead, &ov ) )
  22. 	{
  23. 		if( GetLastError() != ERROR_IO_PENDING )
  24. 		{
  25. 			cout << "Read com failed." << endl;
  26. 			return 0;
  27. 		}
  28. 		WaitForSingleObject( ov.hEvent, INFINITE );
  29. 		GetOverlappedResult( g_hCom, &ov, &dwRead, TRUE );
  30. 	}
  31. 	if( dwRead != strlen( g_pData ) )
  32. 	{
  33. 		cout << "Failed to get all the data." << endl;
  34. 		return 0;
  35. 	}
  36. 	cout << "Read: " << szBuf << endl;
  37. 	return 1;
  38. }
  39.  
  40.  
  41. int main()
  42. {
  43. 	g_hCom = CreateFile( "com1", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL );
  44. 	assert( g_hCom != INVALID_HANDLE_VALUE );
  45.  
  46. 	HANDLE hThread = CreateThread( NULL, 0, ThreadRead, NULL, 0, NULL );
  47. 	assert( hThread );
  48.  
  49. 	Sleep( 100 );
  50.  
  51. 	DWORD dwWritten;
  52. 	OVERLAPPED ov;
  53. 	memset( &ov, 0, sizeof( ov ) );
  54. 	ov.hEvent = CreateEvent( NULL, TRUE, TRUE, NULL );
  55. 	assert( ov.hEvent );
  56.  
  57. 	if( !WriteFile( g_hCom, g_pData, strlen( g_pData ), &dwWritten, &ov ) )
  58. 	{
  59. 		if( GetLastError() != ERROR_IO_PENDING )
  60. 		{
  61. 			cout << "Write com failed." << endl;
  62. 			return 0;
  63. 		}
  64. 		WaitForSingleObject( ov.hEvent, INFINITE );
  65. 		GetOverlappedResult( g_hCom, &ov, &dwWritten, TRUE );
  66. 	}
  67. 	if( dwWritten != strlen( g_pData ) )
  68. 	{
  69. 		cout << "Failed to write all the data." << endl;
  70. 		return 0;
  71. 	}
  72. 	cout << "Write: " << g_pData << endl;
  73.  
  74. 	Sleep( 100 );
  75. 	return 1;
  76. }

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