用VB编写读取mp3音频并显示频谱的代码

### 回答1：
你好，这里是一段可以使用 Visual Basic (VB) 编写的读取 MP3 音频并显示频谱的代码。

首先，在你的 VB 项目中添加一个按钮，并将下面的代码添加到按钮的单击事件处理程序中。

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
  ' 读取 MP3 文件
  Dim filePath As String = "C:\path\to\your\audio.mp3"
  Dim audio As Byte() = File.ReadAllBytes(filePath)

  ' 创建 FFT 对象
  Dim fft As New FFT()

  ' 获取频谱数据
  Dim spectrum As Single() = fft.GetSpectrumData(audio)

  ' 在图表中显示频谱数据
  Dim chart As New Chart()
  chart.Series.Add("Spectrum")
  For i As Integer = 0 To spectrum.Length - 1
    chart.Series("Spectrum").Points.AddY(spectrum(i))
  Next
End Sub

在上面的代码中，我们使用了 `FFT` 类来获取频谱数据。这个类需要你自己实现，具体实现方法可以参考这篇文章: https://www.cnblogs.com/ZhouYi/p/4536809.html。

然后，我们将获取的频谱数据添加到图表中，并使用图表控件来显示频谱。

我希望这段代码能够对你有所帮助。如果你有其他问题，请随时联系我。

### 回答2：
下面是用VB编写读取mp3音频并显示频谱的简单代码示例：

Imports NAudio.Wave
Imports System.Drawing

Public Class MainForm
    Inherits Form

    Dim audioFile As String = "audio.mp3"
    Dim sampleProvider As ISampleProvider
    Dim fftSize As Integer = 4096

    Protected Overrides Sub OnLoad(e As EventArgs)
        ' 初始化NAudio WaveStream以及SampleProvider
        Dim waveStream As WaveStream = New Mp3FileReader(audioFile)
        sampleProvider = waveStream.ToSampleProvider()

        ' 设置FFT处理器以及获取频谱数据
        Dim fftProcessor As New FFTProcessor(sampleProvider.WaveFormat.SampleRate, fftSize)
        Dim spectrumData As List(Of Single()) = fftProcessor.GetSpectrumData(waveStream)

        ' 绘制频谱图
        Dim pictureBox As New PictureBox()
        pictureBox.Location = New Point(10, 10)
        pictureBox.Size = New Size(Me.ClientSize.Width - 20, Me.ClientSize.Height - 20)
        pictureBox.Image = DrawSpectrum(spectrumData, pictureBox.Size)
        Me.Controls.Add(pictureBox)

        MyBase.OnLoad(e)
    End Sub

    Private Function DrawSpectrum(spectrumData As List(Of Single()), size As Size) As Bitmap
        Dim bitmap As New Bitmap(size.Width, size.Height)
        Dim graphics As Graphics = Graphics.FromImage(bitmap)

        Dim xScale As Single = size.Width / spectrumData.Count
        Dim yScale As Single = size.Height / (fftSize / 2)

        For i As Integer = 0 To spectrumData.Count - 1
            For j As Integer = 0 To fftSize / 2 - 1
                Dim intensity As Single = spectrumData(i)(j)
                Dim color As Color = Color.FromArgb(CInt(intensity * 255), 0, 0)
                graphics.FillRectangle(New SolidBrush(color), i * xScale, size.Height - j * yScale, xScale, yScale)
            Next
        Next

        graphics.Dispose()
        Return bitmap
    End Function
End Class

Public Class FFTProcessor
    Dim sampleRate As Integer
    Dim fftSize As Integer

    Public Sub New(sampleRate As Integer, fftSize As Integer)
        Me.sampleRate = sampleRate
        Me.fftSize = fftSize
    End Sub

    Public Function GetSpectrumData(waveStream As WaveStream) As List(Of Single())
        Dim buffer As New List(Of Single())
        Dim sampleBuffer(fftSize - 1) As Single
        Dim fft As New FFT(fftSize)

        Do While waveStream.Position < waveStream.Length
            Dim read As Integer = waveStream.Read(sampleBuffer, 0, fftSize)
            If read > 0 Then
                Dim fftData() As Single = fft.ComputeFFT(sampleBuffer)
                buffer.Add(fftData)
            End If
        Loop

        Return buffer
    End Function
End Class

Public Class FFT
    Dim fftSize As Integer

    Public Sub New(fftSize As Integer)
        Me.fftSize = fftSize
    End Sub

    Public Function ComputeFFT(input As Single()) As Single()
        Dim fftData(fftSize / 2 - 1) As Single

        ' FFT处理代码

        Return fftData
    End Function
End Class

以上代码使用了NAudio库来读取mp3音频文件，并通过FFT处理器计算频谱数据。然后通过绘制频谱图的方法将频谱数据绘制到一个PictureBox控件上。代码中的FFT处理器只是简单示例，实际应用中可能需要根据具体需求进行调整。

### 回答3：
使用VB编写读取mp3音频并显示频谱的代码可以通过以下步骤实现：

1. 首先，需要在VB项目中添加对NAudio库的引用。在Visual Studio中，右键点击项目名称，选择“添加”>“引用”，然后找到NAudio并添加引用。

2. 创建一个新的窗体，并在窗体上添加一个扩展了PictureBox的控件，用于显示频谱。

3. 在窗体的代码中引入NAudio库的命名空间：`Imports NAudio.Wave`

4. 声明一个私有变量`wavePlayer`作为音频播放器：`Private wavePlayer As WaveOut`

5. 添加一个按钮或其他触发事件的控件，并在事件处理程序中编写以下代码：

Private Sub btnOpen_Click(sender As Object, e As EventArgs) Handles btnOpen.Click
    Dim openFileDialog As New OpenFileDialog()
    openFileDialog.Filter = "MP3 Files|*.mp3"
    openFileDialog.Title = "选择音频文件"
    
    If openFileDialog.ShowDialog() = DialogResult.OK Then
        ' 创建一个读取mp3的音频流
        Dim audioFileReader As New AudioFileReader(openFileDialog.FileName)
        
        ' 创建一个32位浮点数的音频流，用于分析频谱
        Dim sampleProvider As New SampleChannel(audioFileReader)
        
        ' 创建音频播放器
        wavePlayer = New WaveOut()
        
        ' 注册一个事件，当播放完毕后停止播放器
        AddHandler wavePlayer.PlaybackStopped, AddressOf WavePlayer_PlaybackStopped
        
        ' 将音频流连接到播放器
        wavePlayer.Init(sampleProvider)
        
        ' 启动音频播放器
        wavePlayer.Play()
        
        ' 在图像框中显示频谱
        ShowSpectrum(sampleProvider)
    End If
End Sub

Private Sub ShowSpectrum(sampleProvider As ISampleProvider)
    Dim fftSize As Integer = 8192 ' 设置FFT的大小
    Dim spectrumData(fftSize / 2 - 1) As Single ' 用于存储频谱数据
    
    ' 创建一个曲线，用于显示频谱
    Dim spectrumCurve As New NAudio.Dsp.FastFourierTransform(
        fftSize, NAudio.Dsp.FFTWindow.Hamming)
    
    While wavePlayer.PlaybackState = PlaybackState.Playing
        ' 从音频流中读取指定长度的采样数据
        Dim buffer(sampleProvider.WaveFormat.SampleRate * 
            sampleProvider.WaveFormat.Channels) As Single
        sampleProvider.Read(buffer, 0, buffer.Length)
        
        ' 分析频谱
        spectrumCurve.Magnitude(buffer, spectrumData)
        
        ' 在图像框中显示频谱数据
        spectrumPictureBox.Image = DrawSpectrum(spectrumData)
        
        Application.DoEvents() ' 处理其他事件
    End While
End Sub

Private Function DrawSpectrum(spectrumData() As Single) As Image
    Dim width As Integer = spectrumPictureBox.Width
    Dim height As Integer = spectrumPictureBox.Height
    Dim image As New Bitmap(width, height)
    Dim graphics As Graphics = Graphics.FromImage(image)
    
    ' 绘制频谱曲线
    For i As Integer = 0 To spectrumData.Length - 1
        Dim barHeight As Integer = CInt(height * spectrumData(i))
        graphics.DrawLine(Pens.Black, i, height, i, height - barHeight)
    Next
    
    graphics.Dispose()
    
    Return image
End Function

Private Sub WavePlayer_PlaybackStopped(sender As Object, e As StoppedEventArgs)
    ' 停止频谱显示
    spectrumPictureBox.Image = Nothing
End Sub

以上代码通过NAudio库读取MP3音频文件并从音频流中获取采样数据，然后使用快速傅里叶变换（FFT）分析采样数据获得频谱数据，并将频谱数据可视化显示在PictureBox控件上。同时，创建了一个音频播放器用于播放音频文件，并在播放完毕后停止播放器。