Protected MustOverride Function BuildWindowCore ( _
    hwndParent As HandleRef _
) As HandleRef

Dim hwndParent As HandleRef
Dim returnValue As HandleRef

returnValue = Me.BuildWindowCore(hwndParent)

protected abstract HandleRef BuildWindowCore(
    HandleRef hwndParent
)

protected:
virtual HandleRef BuildWindowCore(
    HandleRef hwndParent
) abstract

protected abstract HandleRef BuildWindowCore(
    HandleRef hwndParent
)

protected abstract function BuildWindowCore(
    hwndParent : HandleRef
) : HandleRef

不能在 XAML 中使用方法。