Mingw，XAudio2和GetProcAddress失敗

Question

我正在嘗試在Mingw中使用XAudio2。由於我無法弄清楚我想讓Mingw連接XAudio2，我想我會嘗試純粹通過dll加載來使用XAudio2。但是下面的代碼未能找到帶有GetProcAddress的XAudio2Create。

#include <windows.h> 

static HMODULE xaudio2 = NULL; 

int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance, LPSTR lpcmdline, int ncmdshow) { 
    xaudio2 = LoadLibraryA("XAudio2_2.dll"); 
    if (xaudio2 == NULL) { 
     MessageBox(NULL, L"LoadLibrary failed", 0, 0); 
    } 

    void* fnc = GetProcAddress(xaudio2, "XAudio2Create"); 
    if (fnc == NULL) { 
     MessageBox(NULL, L"GetProcAddress failed", 0, 0); 
    } 

    return 0; 
} 

Answer 1

我想通了你必須通過COM和CoCreateInstance（）。類似於

#include <windows.h> 
#include <stdio.h> 
#include <XAudio2.h> 

int WINAPI WinMain(HINSTANCE hinstance, HINSTANCE hprevinstance, LPSTR lpcmdline, int ncmdshow) { 
    WAVEFORMATEX format; 
    format.wFormatTag = 1; 
    format.nChannels = 1; 
    format.nSamplesPerSec = 44100; 
    format.nAvgBytesPerSec = 44100; 
    format.nBlockAlign = 1; 
    format.wBitsPerSample = 8; 
    format.cbSize = 0; 

    CoInitializeEx(NULL, COINIT_MULTITHREADED); 

    IXAudio2* pXAudio2 = NULL; 
    IXAudio2SourceVoice* source = NULL; 
    IXAudio2MasteringVoice* master = NULL; 

    HRESULT hr; 
    if (FAILED(hr = XAudio2Create(&pXAudio2, 0, XAUDIO2_DEFAULT_PROCESSOR))) { 
     MessageBox(0, L"hi", L"hi", 0); 
    } 

    if (FAILED(hr = pXAudio2->CreateMasteringVoice(&master))) { 
     MessageBox(0, L"hi", L"hi", 0); 
    } 

    if (FAILED(hr = pXAudio2->CreateSourceVoice(&source, &format))) { 
     MessageBox(0, L"hi", L"hi", 0); 
    } 

    char str[30]; 

    float freq = 0.0; 
    source->GetFrequencyRatio(&freq); 
    sprintf(str, "%f", freq); 
     MessageBoxA(0, str, str, 0); 

    UINT32 OperationSetCounter = 0; 
    UINT32 OperationID = UINT32(InterlockedIncrement(LPLONG(&OperationSetCounter))); 

    if (FAILED(hr = source->SetFrequencyRatio(1.1,OperationID))) { 
     MessageBox(0, L"hi", L"hi", 0); 
    } 

    if (FAILED(hr = pXAudio2->CommitChanges(OperationID))) { 
     MessageBox(0, L"hi", L"hi", 0); 
    } 



    float freq2 = 0.0; 
    source->GetFrequencyRatio(&freq2); 
    sprintf(str, "%f", freq2); 
    MessageBoxA(0, str, str, 0); 

    Sleep(2000); 
    float freq3 = 0.0; 
    source->GetFrequencyRatio(&freq3); 
    sprintf(str, "%f", freq3); 
    if (freq3 != 1.0) { 
     MessageBoxA(0, str, str, 0); 
    } 

    source->Start(0); 
    return 0; 
}