vb.net - 非托管 IPictureDisp 到托管对象

Question

我正在使用 VB.Net 为 Excel 工作 Api 调用 dll。（Robert Giesecke 的非托管导出）标准类型（数字、字符串）正在工作。但是，当尝试使用对象类型时返回错误。

错误消息是：“未知名称。（返回的 HRESULT 异常：0x80020006 (DISP_E_UNKNOWNNAME)）”

我的功能是（错误是 IPictureDisp 到位图）：

Public Function GetTextQR_FromPicture(ByVal pictureDisp As IPictureDisp) As [MarshalAs(UnmanagedType.BStr)] String
      'IPictureDisp
      Return _qrDec.decode(New QRCodeBitmapImage(PicHelper.GetPictureFromIPictureDisp(pictureDisp)), Encoding.UTF8)
End Function

我的助手类：

Friend Class PicHelper
   Inherits System.Windows.Forms.AxHost

   Friend Sub New()
      MyBase.New(Nothing)
   End Sub

   Friend Shared Shadows Function GetIPictureDispFromPicture(image As Image) As Object
      Return System.Windows.Forms.AxHost.GetIPictureDispFromPicture(image)
   End Function

   Friend Shared Shadows Function GetPictureFromIPictureDisp(picture As IPictureDisp) As Image
      Return System.Windows.Forms.AxHost.GetPictureFromIPictureDisp(picture)
   End Function
End Class

标签： vb.netdllunmanaged