我正在尝试从Form1重写代码，并学习如何在不同的classes中实现代码，如Functions、Properties等...
现在我已经创建了一个Sub，它可以为我的视频提供YouTube标题，我知道我可以使用API顺便说一句，但由于我测试了很多，我的API限制将立即关闭。
问题是，即使我在函数Public Shared Property Frm As New Form1中声明，或者我为标签设置了一个invoke sub，我仍然会得到错误：
System.NullReferenceException:'对象引用未设置为对象的示例。'
下面是我在RegularExpressions.vb中的代码：

Imports System.Text.RegularExpressions
Imports Leaf.xNet

Public Class RegularExpressions
    Public Shared Property Frm As New Form1
    Friend Shared Mainform As Form1
    Public Shared Property txtTitle As Label

    Public Shared Sub getValues_Offline_Title()

        Using req As New HttpRequest()
            Dim Offline_Title As String
            Dim url As String
            Dim _videoID As String = Functions.VideoURL_link.ToString

            req.AddHeader("Host", "www.youtube.com")
            req.AddHeader("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.0.0 Safari/537.36")
            req.AddHeader("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8")
            req.AddHeader("Accept-Language", "en-US,en;q=0.9,cs;q=0.8,de;q=0.7,fr;q=0.6,hu;q=0.5")
            req.AddHeader("Accept-Encoding", "gzip, deflate")
            req.AddHeader("Referrer", $"https://www.youtube.com/watch?v={_videoID}")

            Dim strData As String = req.[Get](String.Concat("https://www.youtube.com/watch?v=", _videoID), Nothing).ToString()
            Dim url2 = strData.ToString
            url = strData.ToString().Split({"twoColumnWatchNextResults"":"}, StringSplitOptions.None)(1).Split("]"c)(0)
            Offline_Title = url.Split(New String() {"text"":"""}, StringSplitOptions.None)(1).Split(""""c)(0)
            'MessageBox.Show(Offline_Title)
            Frm.Invoke(Sub() txtTitle.Text = Offline_Title.ToString)
            'Mainform.lbl_Views_sent.Text = Offline_Title.ToString
        End Using
    End Sub

End Class

这个方法在Form1加载时被调用，并且有2个单选按钮。如果单选按钮1被选中，那么它应该显示离线视频标题，否则单选按钮2被选中，那么它应该显示实时视频标题。

Private Sub RadioButton1_CheckedChanged(sender As Object, e As EventArgs) Handles RadioButton1.CheckedChanged
    If RadioButton1.Checked Then
         RegularExpressions.getValues_Offline_Title()
    Else
         RegularExpressions.getValues_Live_Title()
    End If
End Sub