DDX_Text(pDX,IDC_EDITINPUT,m_edtText)中,pDX代表的是什么

The DDX_Text function manages the transfer of int, UINT, long, DWORD, CString, float, or double data between an edit control in a dialog box, form view, or control view and a CString data member of the dialog box, form view, or control view object.

Parameters
pDX
A pointer to a CDataExchange object. The framework supplies this object to establish the context of the data exchange, including its direction.

nIDC
The ID of an edit control in the dialog box, form view, or control view object.

value
A reference to a data member in the dialog box, form view, or control view object. The data type of value depends on which of the overloaded versions of DDX_Text you use.

你需要传递的数据（地址引用）。