private static WinXpDllInterface.MIXER InnerGetMixer(int i, uint type, uint ctrlType, out int currVolume)
{
currVolume = -1;
WinXpDllInterface.LINECONTROLS mlc = new WinXpDllInterface.LINECONTROLS();
WinXpDllInterface.MIXERLINE mxl = new WinXpDllInterface.MIXERLINE();
WinXpDllInterface.MIXERDETAILS xdl = new WinXpDllInterface.MIXERDETAILS();
WinXpDllInterface.UMIXERDETAILS uxdl = new WinXpDllInterface.UMIXERDETAILS();
WinXpDllInterface.MIXER mixerControl = new WinXpDllInterface.MIXER();
mxl.cbStruct = (uint)Marshal.SizeOf(mxl);
mxl.dwComponentType = (uint)type;
int details = WinXpDllInterface.mixerGetLineInfoA(i, ref mxl, WinXpDllInterface.MIXER_GETLINEINFOF_COMPONENTTYPE);
if (WinXpDllInterface.MMSYSERR_NOERROR == details)
{
int mcSize = 152;
int control = Marshal.SizeOf(typeof(WinXpDllInterface.MIXER));
mlc.pamxctrl = Marshal.AllocCoTaskMem(mcSize);
mlc.cbStruct = (uint)Marshal.SizeOf(mlc);
mlc.dwLineID = mxl.dwLineID;
mlc.dwControl = (uint)ctrlType;
mlc.cControls = 1;
mlc.cbmxctrl = (uint)mcSize;
mixerControl.cbStruct = mcSize;
details = WinXpDllInterface.mixerGetLineControlsA(i, ref mlc, WinXpDllInterface.MIXER_GETLINECONTROLSF_ONEBYTYPE);
bool result = WinXpDllInterface.MMSYSERR_NOERROR == details;
if (result)
{
mixerControl = (WinXpDllInterface.MIXER)Marshal.PtrToStructure(mlc.pamxctrl, typeof(WinXpDllInterface.MIXER));
int mcDetailsSize = Marshal.SizeOf(typeof(WinXpDllInterface.MIXERDETAILS));
int mcDetailsUnsigned = Marshal.SizeOf(typeof(WinXpDllInterface.UMIXERDETAILS));
xdl.cbStruct = mcDetailsSize;
xdl.dwControlID = mixerControl.dwControlID;
xdl.paDetails = Marshal.AllocCoTaskMem(mcDetailsUnsigned);
xdl.cChannels = 1;
xdl.item = 0;
xdl.cbDetails = mcDetailsUnsigned;
details = WinXpDllInterface.mixerGetControlDetailsA(i, ref xdl, WinXpDllInterface.MIXER_GETCONTROLDETAILSF_VALUE);
uxdl = (WinXpDllInterface.UMIXERDETAILS)Marshal.PtrToStructure(xdl.paDetails, typeof(WinXpDllInterface.UMIXERDETAILS));
currVolume = uxdl.dwValue;
return(mixerControl);
}
}
return(mixerControl);
}
private static bool InnerSetMixer(int i, WinXpDllInterface.MIXER mixer, int volume)
{
WinXpDllInterface.MIXERDETAILS xdl = new WinXpDllInterface.MIXERDETAILS();
WinXpDllInterface.UMIXERDETAILS uxdl = new WinXpDllInterface.UMIXERDETAILS();
xdl.item = 0;
xdl.dwControlID = mixer.dwControlID;
xdl.cbStruct = Marshal.SizeOf(xdl);
xdl.cbDetails = Marshal.SizeOf(uxdl);
xdl.cChannels = 1;
uxdl.dwValue = volume;
xdl.paDetails = Marshal.AllocCoTaskMem(Marshal.SizeOf(typeof(WinXpDllInterface.UMIXERDETAILS)));
Marshal.StructureToPtr(uxdl, xdl.paDetails, false);
int details = WinXpDllInterface.mixerSetControlDetails(i, ref xdl, WinXpDllInterface.MIXER_SETCONTROLDETAILSF_VALUE);
return(WinXpDllInterface.MMSYSERR_NOERROR == details);
}
private static void SetVolume(int volume)
{
InvokeTryCatch("WinXpVolumeOperate.SetVolume", () =>
{
int currVolume;
int mixerControl;
WinXpDllInterface.mixerOpen(out mixerControl, 0, 0, 0, 0);
uint controlType = WinXpDllInterface.MIXERCONTROL_CONTROLTYPE_VOLUME;
WinXpDllInterface.MIXER mixer = InnerGetMixer(mixerControl, WinXpDllInterface.MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, controlType, out currVolume);
bool setSucceed = false;
for (int i = 0; i < 3; i++)
{
if (volume > mixer.lMaximum)
{
volume = mixer.lMaximum;
}
if (volume < mixer.lMinimum)
{
volume = mixer.lMinimum;
}
InnerSetMixer(mixerControl, mixer, volume);
mixer = InnerGetMixer(mixerControl, WinXpDllInterface.MIXERLINE_COMPONENTTYPE_DST_SPEAKERS, controlType, out currVolume);
if (volume == currVolume)
{
setSucceed = true; break;
} //如果设置失败, 则最多重试3次
}
WinXpDllInterface.mixerClose(mixerControl);
if (!setSucceed)
{
throw new Exception("多次尝试设置 Xp操作系统音量 失败 (该异常可能是偶发异常, 可以忽略)!");
}
});
}
