UE4鼠标焦点不在窗口没有声音

修改配置文件：

引擎配置文件：BaseEngine.ini

[Audio]
MaxChannels=32
CommonAudioPoolSize=0
UnfocusedVolumeMultiplier=0.0
UseAudioThread=true
EnableAudioMixer=false

拷贝到项目配置文件：DefaultEngine.ini

Audio]
MaxChannels=32
CommonAudioPoolSize=0
UnfocusedVolumeMultiplier=1.0
UseAudioThread=true
EnableAudioMixer=false

修改UnfocusedVolumeMultiplier=1.0

 

//App.cpp
static bool GUnfocusedVolumeMultiplierInitialised = false;
float FApp::GetUnfocusedVolumeMultiplier()
{
	if (!GUnfocusedVolumeMultiplierInitialised)
	{
		GUnfocusedVolumeMultiplierInitialised = true;
		GConfig->GetFloat(TEXT("Audio"), TEXT("UnfocusedVolumeMultiplier"), UnfocusedVolumeMultiplier, GEngineIni);
	}
	return UnfocusedVolumeMultiplier;
}

void FApp::SetUnfocusedVolumeMultiplier(float InVolumeMultiplier)
{
	UnfocusedVolumeMultiplier = InVolumeMultiplier;
	GConfig->SetFloat(TEXT("Audio"), TEXT("UnfocusedVolumeMultiplier"), UnfocusedVolumeMultiplier, GEngineIni);
	GUnfocusedVolumeMultiplierInitialised = true;
}

//WindowsPlatformApplicationMisc.cpp
void FWindowsPlatformApplicationMisc::PumpMessages(bool bFromMainLoop)
{
	if (!bFromMainLoop)
	{
		TGuardValue PumpMessageGuard( GPumpingMessagesOutsideOfMainLoop, true );
		// Process pending windows messages, which is necessary to the rendering thread in some rare cases where D3D
		// sends window messages (from IDXGISwapChain::Present) to the main thread owned viewport window.
		WinPumpSentMessages();
		return;
	}

	GPumpingMessagesOutsideOfMainLoop = false;
	WinPumpMessages();

	// Determine if application has focus
	bool HasFocus = FApp::UseVRFocus() ? FApp::HasVRFocus() : FWindowsPlatformApplicationMisc::IsThisApplicationForeground();

	// If editor thread doesn't have the focus, don't suck up too much CPU time.
	if( GIsEditor )
	{
		static bool HadFocus=1;
		if( HadFocus && !HasFocus )
		{
			// Drop our priority to speed up whatever is in the foreground.
			SetThreadPriority( GetCurrentThread(), THREAD_PRIORITY_BELOW_NORMAL );
		}
		else if( HasFocus && !HadFocus )
		{
			// Boost our priority back to normal.
			SetThreadPriority( GetCurrentThread(), THREAD_PRIORITY_NORMAL );
		}
		if( !HasFocus )
		{
			// Sleep for a bit to not eat up all CPU time.
			FPlatformProcess::Sleep(0.005f);
		}
		HadFocus = HasFocus;
	}

	// if its our window, allow sound, otherwise apply multiplier
	FApp::SetVolumeMultiplier( HasFocus ? 1.0f : FApp::GetUnfocusedVolumeMultiplier() );
}