[混编] 问题：vb.net调用dll找不到模块

Public Class ricker_vb

    Private Declare Sub ricker Lib "D:\chengxu\VB\ricker_vb\ricker_vb\ricker_f.dll" _
                               (ByRef fz As Single, _
                                ByRef dt As Single, _
                                ByRef tmax As Long)

    Private Sub Btn_run_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Btn_run.Click

        Dim fz As Single
        Dim dt As Single
        Dim tmax As Long

        fz = Text_fz.Text
        dt = Text_dt.Text
        tmax = Text_tmax.Text
        Call ricker(fz, dt, tmax)

    End Sub
End Class