c++/clr 控件如何响应DragDrop事件

[我是菜鸟999]

Form窗体的AllowDrop属性true
dotnetbar.panelex的AllowDrop属性true
dotnetbar.listviewex的AllowDrop属性true

想实现拖拽任何文件到listviewex上都能得到路径
但是，实际使用时没有任何反应。以下参考了微软的例子。

private: System::Void listViewEx_Strategys_DragOver(System::Object^  sender, System::Windows::Forms::DragEventArgs^  e) {
			 if (  !e->Data->GetDataPresent( System::String::typeid ) )
			 {
				 e->Effect = DragDropEffects::None;
				 this->labelItem_InfoTips->Text = "None - no string data.";
				 return;
			 }

			 // Set the effect based upon the KeyState.
			 if ( (e->KeyState & (8 + 32)) == (8 + 32) && ((e->AllowedEffect & DragDropEffects::Link) == DragDropEffects::Link) )
			 {
				 // KeyState 8 + 32 = CTL + ALT
				 // Link drag-and-drop effect.
				 e->Effect = DragDropEffects::Link;
			 }
			 else
				 if ( (e->KeyState & 32) == 32 && ((e->AllowedEffect & DragDropEffects::Link) == DragDropEffects::Link) )
				 {
					 // ALT KeyState for link.
					 e->Effect = DragDropEffects::Link;
				 }
				 else
					 if ( (e->KeyState & 4) == 4 && ((e->AllowedEffect & DragDropEffects::Move) == DragDropEffects::Move) )
					 {
						 // SHIFT KeyState for move.
						 e->Effect = DragDropEffects::Move;
					 }
					 else
						 if ( (e->KeyState & 8) == 8 && ((e->AllowedEffect & DragDropEffects::Copy) == DragDropEffects::Copy) )
						 {
							 // CTL KeyState for copy.
							 e->Effect = DragDropEffects::Copy;
						 }
						 else
							 if ( (e->AllowedEffect & DragDropEffects::Move) == DragDropEffects::Move )
							 {
								 // By default, the drop action should be move, if allowed.
								 e->Effect = DragDropEffects::Move;
							 }
							 else
								 e->Effect = DragDropEffects::None;


		 }

添加KeyUp函数却可以响应。

private: System::Void listViewEx_Strategys_KeyUp(System::Object^  sender, System::Windows::Forms::KeyEventArgs^  e) {
			 if (e->KeyCode == Keys::Delete)
			 {
				 this->listViewEx_Strategys->Items->Remove(this->listViewEx_Strategys->FocusedItem);
			 }
		 }

请问，怎么才能让DragDrop工作？

[我是菜鸟999]

DevComponents::DotNetBar::Controls::ListViewEx的AllowDrop属性如果是true，则添加数据失败，不知道什么原因。

[我是菜鸟999]

唉！这个东西是不是太冷门了，都没人来啊