如何设置CONST_DSBCAPSFLAGS.DSBCAPS_PRIMARYBUFFER？？

beelzebub918

DirectSound = DirectX.DirectSoundCreate("");
                        DirectSound.SetCooperativeLevel(this.Handle.ToInt32(), CONST_DSSCLFLAGS.DSSCL_NORMAL);
                        DSBufferDesc.lFlags = (CONST_DSBCAPSFLAGS.DSBCAPS_CTRLFREQUENCY | CONST_DSBCAPSFLAGS.DSBCAPS_CTRLPAN | CONST_DSBCAPSFLAGS.DSBCAPS_CTRLVOLUME | CONST_DSBCAPSFLAGS.DSBCAPS_STATIC);
　　　　        //DSBufferDesc.lFlags = CONST_DSBCAPSFLAGS.DSBCAPS_PRIMARYBUFFER;

        　　　　DSBufferDesc.lBufferBytes = 0;
　　        　　DSBufferDesc.lpwfxFormat = 0;

                        WaveFormat.nFormatTag = (short)CONST_DSOUND.WAVE_FORMAT_PCM;
                        WaveFormat.nChannels = 1;          // 1= Mono, 2 = Stereo
                        WaveFormat.lSamplesPerSec = 22050; // Samples per second
                        WaveFormat.nBitsPerSample = 16;    //16 =16bit, 8=8bit
                        WaveFormat.nBlockAlign     = (short)(WaveFormat.nBitsPerSample / 8 * WaveFormat.nChannels);
                        WaveFormat.lAvgBytesPerSec = WaveFormat.lSamplesPerSec * WaveFormat.nBlockAlign;

                        //MessageBox.Show(Application.StartupPath + "\\bgmusic.wav");
                        DirectSoundBuffer = DirectSound.CreateSoundBufferFromFile(Application.StartupPath + "\\bgmusic.wav" ,ref DSBufferDesc, out WaveFormat);                       
                        DirectSoundBuffer.Play(CONST_DSBPLAYFLAGS.DSBPLAY_DEFAULT);
//////////////////////////////////////////////////
我把上面的DSBufferDesc.lFlags改为CONST_DSBCAPSFLAGS.DSBCAPS_PRIMARYBUFFER就出问题，不该可以播放音乐，可是鼠标点到其他的窗体上面就没声音了。改如何修改呢???
[em20]

beelzebub918

不会没有人回答吧？？？