c#中利用Bass.dll声音处理类库绘制频谱图

通过引用Bass.Net.dll这个声音处理类库就可以轻松的获取频谱图数据并绘制频谱图。

public void DrawFFT(Graphics g)
        {
            if (Bass.BASS_ChannelIsActive(SystemFont.Stream) == BASSActive.BASS_ACTIVE_PLAYING)
            {
                Bass.BASS_ChannelGetData(SystemFont.Stream, SystemFont.FFTDatas,(int)BASSData.BASS_DATA_FFT1024);
                for (SystemFont.i = 0; SystemFont.i < SystemFont.FFTDatas.Length-1; SystemFont.i++)
                {
                    SystemFont.Di = (int)(Math.Abs(SystemFont.FFTDatas[SystemFont.i]) * 1792);
                    if (SystemFont.Di > this.Height)
                        SystemFont.Di = this.Height;
                    if (SystemFont.Di >= SystemFont.FFTPeacks[SystemFont.i])
                        SystemFont.FFTPeacks[SystemFont.i] = SystemFont.Di;
                    else
                        SystemFont.FFTPeacks[SystemFont.i] = SystemFont.FFTPeacks[SystemFont.i] - 1;
                    if (SystemFont.Di >= SystemFont.FFTFall[SystemFont.i])
                        SystemFont.FFTFall[SystemFont.i] = SystemFont.Di;
                    else
                        SystemFont.FFTFall[SystemFont.i] = SystemFont.FFTFall[SystemFont.i]-1;
                    if ((this.Height - SystemFont.FFTPeacks[SystemFont.i]) > this.Height)
                        SystemFont.FFTPeacks[SystemFont.i] = this.Height;
                    if ((this.Height - SystemFont.FFTFall[SystemFont.i]) > this.Height)
                        SystemFont.FFTFall[SystemFont.i] = this.Height;
                    g.FillRectangle(solidBrush, SystemFont.i * (w+2), this.Height - SystemFont.FFTFall[SystemFont.i],w, this.Height);
                }
            }
            else
            {
                return;
            }
        }

效果如下：