从VB6.0调用C ++ DLL中的函数 [英] Calling A Function in C++ DLL from VB6.0

问题描述

大家好，我一直在尝试从VB6.0中调用C ++ DLL中的一个函数，但它不能正常工作。它会生成一条错误消息，指出"运行时错误49：错误的DLL调用约定"。

这个DLL的工作/功能是创建一个新的语音日志，它将连接到我的VoIP软件的各种用户的音频（对话）混合成MP3文件。


以下是我的代码，请仔细阅读并提供帮助。

提前致谢。

适用于VoiceLog.h（C / C ++标题）

 //以下ifdef块是创建宏的标准方法，它使得从DLL中导出
 //更简单。此DLL中的所有文件都使用命令行中定义的VOICELOG_EXPORTS 
 //符号进行编译。不应在使用此DLL的任何项目
 //上定义此符号。这样，源文件包含此文件的任何其他项目都会看到
 // VOICELOG_API函数从DLL导入，而此DLL看到使用此宏定义的符号
 //正在导出。 
 #ifdef VOICELOG_EXPORTS 
 #define VOICELOG_API __declspec（dllexport）
 #else 
 #define VOICELOG_API __declspec（dllimport）
 #endif 
 
＃ ifdef __cplusplus 
 extern"C" {
 #endif 
 
 ///创建一个新的语音日志，将音频混合到MP3文件中。 
 /// @param szTempDir存储临时文件的目录（.wav文件）
 /// @param szMP3FileName MP3文件的输出路径，例如： 
 /// C：\conversation.mp3 
 /// @param nSecFlushInterval每次
 ///临时.wav文件混合并编码为MP3-之间的秒数格式。 
 /// @see VL_CloseVoiceLog 
 VOICELOG_API BOOL VL_CreateVoiceLog（IN LPCSTR szTempDir，
 IN LPCSTR szMP3FileName，
 IN INT32 nSecFlushInterval）; 
 
 ///关闭语音日志并完成编码到MP3文件中。 
 /// @param bAbort中止语音日志并跳过最终编码为
 /// MP3文件。 
 /// @see VL_CreateVoiceLog 
 VOICELOG_API BOOL VL_CloseVoiceLog（IN BOOL bAbort）; 
 
 ///检查语音记录当前是否有效。 
 VOICELOG_API BOOL VL_IsVoiceLogging（）; 
 
 ///将音频数据添加到语音日志中。确保将音频
 ///数据添加到语音日志中，当这个人真正开始
 ///谈话时，因为添加音频的时间被用作
 ///偏移当人完成讲话时，请拨打VL_EndStream（。）
 ///，以便语音记录器知道此人已停止说话。如果没有调用
 /// VL_EndStream（。），语音记录器会认为
 ///人不停地说话而没有停顿。 
 /// 
 /// @param nStreamID流的ID，例如：用户的ID。 
 /// @param nSampleRate正在添加的流的采样率
 /// @param lpStreamData原始音频数据的音频缓冲区。 
 /// @param nSampleCount音频缓冲区中的样本数。 
 /// @see VL_EndStream 
 VOICELOG_API BOOL VL_AddStreamData（IN INT32 nStreamID，
 IN INT32 nSampleRate，
 IN CONST SHORT * lpStreamData，
 IN INT32 nSampleCount）; 
 
 ///停止写一个特定的流，因为这个人不再是
 ///说话。 
 /// 
 /// @param nStreamID流的ID，例如：用户的ID。 
 /// @see VL_AddStreamData 
 VOICELOG_API BOOL VL_EndStream（IN INT32 nStreamID）; 
 
 #ifdef __cplusplus 
}; 
 #endif 
 

从VB调用这个功能就是我做的。

我将下面的代码放在一般声明中

 Option Explicit 
 Private Declare Function VL_CreateVoiceLog Lib" VoiceLog。 DLL" （ByVal szTempDir As String，ByVal szMP3FileName As String，ByVal nSecFlushInterval As Integer）As Long 

我将下面的代码放在命令箱中;说CmdRecordConversation。该方法"接收已播放的音频的回叫"。并且它将调用一个事件。

 Private Sub CmdRecordConversation_Click（）
 evoclient1.RegisterTalkingCallback 
 End Sub 

以下是事件中的代码，这是我收到错误消息的地方。

 Private Sub evoclient1_OnUserAudioData（ByVal nUserID As Long，ByVal nSampleRate As Long，pRawAudio（）As Integer，ByVal nSamples As Long）
 Dim szTempDir，szMP3FileName As String 
 Dim FileCountExist As Long 
 Dim nSecFlushInterval As Integer 
 nSecFlushInterval = 10 
 szTempDir = GetSetting（App.EXEName，App.EXEName，" Default Path"）& " \" 
 FileCountExist = filecount（szTempDir）+ 1 
 szMP3FileName = szTempDir& " Conversation.mp3" 
如果FExists（szMP3FileName）那么
 szMP3FileName = szTempDir& " Conversation_" &安培; FileCountExist& " .MP3" 
'开始创建mp3文件
 VL_CreateVoiceLog szTempDir，szMP3FileName，nSecFlushInterval 
否则
 VL_CreateVoiceLog szTempDir，szMP3FileName，nSecFlushInterval 
 End if 
 End Sub 
 
 

解决方案

<这个论坛适用于VB.Net-only questsions。看看这里：
在哪里发布您的VB 6问题 

Hello all, I have been trying to call a function in C++ DLL from VB6.0 but its not working as suppose. It do generate an error message saying "Run-time error 49: Bad DLL calling convention".

The work/function of this DLL is to Create a new voice-log which mixes audio(conversation) of various users connected to my VoIP software into a MP3 file.
Below are my codes, Please go through it and help.
Thanks in advance.

For VoiceLog.h(C/C++ Header)

// The following ifdef block is the standard way of creating macros which make exporting 
// from a DLL simpler. All files within this DLL are compiled with the VOICELOG_EXPORTS
// symbol defined on the command line. this symbol should not be defined on any project
// that uses this DLL. This way any other project whose source files include this file see 
// VOICELOG_API functions as being imported from a DLL, whereas this DLL sees symbols
// defined with this macro as being exported.
#ifdef VOICELOG_EXPORTS
#define VOICELOG_API __declspec(dllexport)
#else
#define VOICELOG_API __declspec(dllimport)
#endif

#ifdef __cplusplus
extern "C" {
#endif

	/// Create a new voice-log which mixes audio into a MP3 file.
	/// @param szTempDir The directory to store temporary files (.wav files)
	/// @param szMP3FileName The output path of the MP3 file, e.g. 
	/// C:\conversation.mp3
	/// @param nSecFlushInterval The number of seconds between each time
	/// the temporary .wav files are mixed and encoded into MP3-format.
	/// @see VL_CloseVoiceLog
	VOICELOG_API BOOL VL_CreateVoiceLog(IN LPCSTR szTempDir, 
		IN LPCSTR szMP3FileName, 
		IN INT32 nSecFlushInterval);

	/// Close the voice-log and finish encoding into the MP3 file.
	/// @param bAbort Abort the voice-log and skip final encoding to
	/// the MP3 file.
	/// @see VL_CreateVoiceLog
	VOICELOG_API BOOL VL_CloseVoiceLog(IN BOOL bAbort);

	/// Check if voice-logging is currently active.
	VOICELOG_API BOOL VL_IsVoiceLogging();

	/// Add audio data to the voice-log. Make sure to add the audio
	/// data to the voice-log when the person is actually starting 
	/// to talk since the time of when the audio is added is used as 
	/// offset. When the person is finished talking call VL_EndStream(.)
	/// so the voice-logger knows the person has stopped talking. If
	/// VL_EndStream(.) is not called the voice-logger will think the
	/// person is constantly talking without pauses.
	///
	/// @param nStreamID The ID of the stream, e.g. the user's ID.
	/// @param nSampleRate The sample rate of the stream being added
	/// @param lpStreamData The audio buffer of raw audio data.
	/// @param nSampleCount The number of samples in the audio buffer.
	/// @see VL_EndStream
	VOICELOG_API BOOL VL_AddStreamData(IN INT32 nStreamID, 
		IN INT32 nSampleRate, 
		IN CONST SHORT* lpStreamData,
		IN INT32 nSampleCount);

	/// Stop writing to a specific stream since the person is no longer
	/// talking.
	///
	/// @param nStreamID The ID of the stream, e.g. the user's ID.
	/// @see VL_AddStreamData
	VOICELOG_API BOOL VL_EndStream(IN INT32 nStreamID);

#ifdef __cplusplus
};
#endif

Calling the function from VB this was what I did.
I placed the code below in the general declaration

Option Explicit
Private Declare Function VL_CreateVoiceLog Lib "VoiceLog.dll" (ByVal szTempDir As String, ByVal szMP3FileName As String, ByVal nSecFlushInterval As Integer) As Long

I placed the code below in a commandbox; say CmdRecordConversation. This method "Receive callbacks of audio which has been played" and it will invoke an event.

Private Sub CmdRecordConversation_Click()
	evoclient1.RegisterTalkingCallback
End Sub

Below is the code in the event and this is where I get error message.

Private Sub evoclient1_OnUserAudioData(ByVal nUserID As Long, ByVal nSampleRate As Long, pRawAudio() As Integer, ByVal nSamples As Long)
Dim szTempDir, szMP3FileName As String
Dim FileCountExist As Long
Dim nSecFlushInterval As Integer
nSecFlushInterval = 10
szTempDir = GetSetting(App.EXEName, App.EXEName, "Default Path") & "\"
FileCountExist = filecount(szTempDir) + 1
szMP3FileName = szTempDir & "Conversation.mp3"
If FExists(szMP3FileName) Then
    szMP3FileName = szTempDir & "Conversation_" & FileCountExist & ".mp3"
    'Start creating mp3 file
    VL_CreateVoiceLog szTempDir, szMP3FileName, nSecFlushInterval
Else
    VL_CreateVoiceLog szTempDir, szMP3FileName, nSecFlushInterval
End If
End Sub

解决方案

Hi,

this forum is for VB.Net-only questsions. Have a look here: Where to post your VB 6 questions 

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