customdd.cpp

来自「讲mfc的书」· C++ 代码 · 共 35 行

#include <stdafx.h>
#include "customdd.h"

// Custom Exchange
void DDX_EnableWindow(CDataExchange *pDX, int id, BOOL &flag)
	{
	CWnd *ctl=pDX->m_pDlgWnd->GetDlgItem(id);
	if (pDX->m_bSaveAndValidate)
		flag=ctl->IsWindowEnabled();
	else
		ctl->EnableWindow(flag);
	}

// Custom validator

void DDV_MinMaxCurrency(CDataExchange *pDX, float val, float min, float max)
	{
	CWnd *editctl=CWnd::FromHandle(pDX->m_hWndLastControl);
	CString s;
	int n;
	if (pDX->m_bSaveAndValidate)
		{
// Using math to decide if anything is left over is bad because of rounding
// errors, so use a string method instead
		editctl->GetWindowText(s);
		n=s.Find('.');
		if (n!=-1 && n+3<s.GetLength())
			{
			AfxMessageBox("Please enter the data to the nearest penny!");
			pDX->Fail();
			}
		DDV_MinMaxFloat(pDX,val,min,max); // let the existing one do the job
		}
	}