MFC工控项目实例之三theApp变量传递对话框参数

承接专栏《MFC工控项目实例之二主菜单制作》
用theApp变量传递对话框参数实时改变iPlotX坐标轴最小值、最大值。
1、新建IDD_SYS_DATA对话框，类名SYS_DATA。

三个编辑框IDC_EDIT1、IDC_EDIT2、IDC_EDIT3变量如图

2、SEAL_PRESSURE.h中添加代码

#include "resource.h"		// main symbols
typedef struct sys_para
{union{struct{double	m_fMaxTime;
double	m_fMinTime;
double	m_fMaxPressure;
double	m_fMinPressure;				};char len1[4096];};}SYS_PARA;class CSEAL_PRESSUREApp : public CWinApp
{
public:CSEAL_PRESSUREApp();SYS_PARA m_sys_data;public:virtual BOOL InitInstance();DECLARE_MESSAGE_MAP()
};extern class CSEAL_PRESSUREApp theApp;

3、SEAL_PRESSUREDlg.h中添加代码

public:
void iPlotX_SHOW();

4、SYS_DATA.cpp中添加代码

void SYS_DATA::OnOK() 
{// TODO: Add extra validation here	if(!UpdateData())return;CDialog::OnOK();theApp.m_sys_data.m_fMaxTime=m_fMaxTime;theApp.m_sys_data.m_fMinPressure=m_fMinPressure;theApp.m_sys_data.m_fMaxPressure=m_fMaxPressure;
}

5、SEAL_PRESSUREDlg.cpp中添加代码

#include "SEAL_PRESSURE.h"
#include "SEAL_PRESSUREDlg.h"
#include "SYS_DATA.h"
#include "iplotchannelx.h"
#include "iPlotAxisX.h"
void CSEAL_PRESSUREDlg::iPlotX_SHOW() 
{// TODO: Add your control notification handler code hereCiPlotAxisX axis;		axis = m_ctrlPlot_1.GetXAxis(0);axis.SetMin(0);axis.SetSpan(theApp.m_sys_data.m_fMaxTime);axis = m_ctrlPlot_1.GetYAxis(0);axis.SetMin(theApp.m_sys_data.m_fMinPressure);axis.SetSpan(theApp.m_sys_data.m_fMaxPressure - theApp.m_sys_data.m_fMinPressure);}void CSEAL_PRESSUREDlg::OnSysData() 
{SYS_DATA dlg;if(dlg.DoModal() == IDOK){iPlotX_SHOW();Invalidate();}
}

运行程序