通过FindWindowEx查找按钮句柄

Question

我试图找到安装窗口的按钮手柄，
但我无法得到按钮的手柄
（我can只获得form的句柄 但Spy++ can获取button。

的句柄

这是我的代码：

    Process.Start("C:\install.exe")
    Do Until FindWindow("TWizardForm", "Setup") <> IntPtr.Zero
        Application.DoEvents()
    Loop
    Dim Formh As IntPtr = FindWindow("TWizardForm", "Setup")
    Dim nextButton As IntPtr = FindWindowEx(Formh, 0, "TNewButton", "&Next >")
    MsgBox(nextButton.tostring) ' = 0 :/

我如何获得按钮句柄（c＃或vb.net）？