处理图片框

我在c++/CLI中使用Winform，我有pictureBox1，我试图编译以下代码，但失败了:

pictureBox1->Image->Dispose();

编译器告诉Dispose is not a member of System::Drawing::Image我试图在c#中使用它，它工作:

pictureBox1.Image.Dispose();

我用的是MS Visual Studio 2010

 delete pictureBox1->Image;   // Dispose the existing bitmap, if any