1、int num1,num2,num3;
char ch1[10],ch2[10],ch3[10];

GetDlgItem(IDC_EDIT1)->GetWindowText(ch1,10);
GetDlgItem(IDC_EDIT2)->GetWindowText(ch2,10);

num1=atoi(ch1);
num2=atoi(ch2);
num3=num1+num2;
itoa(num3,ch3,10);

GetDlgItem(IDC_EDIT3)->SetWindowText(ch3);*/

2、 int num1,num2,num3;
char ch1[10],ch2[10],ch3[10];

GetDlgItemText(IDC_EDIT1,ch1,10);
GetDlgItemText(IDC_EDIT2,ch2,10);

num1=atoi(ch1);
num2=atoi(ch2);
num3=num1+num2;
itoa(num3,ch3,10);

SetDlgItemText(IDC_EDIT3,ch3);*/

3、int num1,num2,num3;
num1=GetDlgItemInt(IDC_EDIT1);
num2=GetDlgItemInt(IDC_EDIT2);

num3=num1+num2;
SetDlgItemInt(IDC_EDIT3,num3);*/

4、UpdateData();
m_num3=m_num1+m_num2;
UpdateData(FALSE);*/

5、 int num1,num2,num3;
char ch1[10],ch2[10],ch3[10];

m_edit1.GetWindowText(ch1,10);
m_edit2.GetWindowText(ch2,10);

num1=atoi(ch1);
num2=atoi(ch2);
num3=num1+num2;
itoa(num3,ch3,10);

m_edit3.SetWindowText(ch3);*/

6、 int num1,num2,num3;
char ch1[10],ch2[10],ch3[10];

//::SendMessage(GetDlgItem(IDC_EDIT1)->m_hWnd,WM_GETTEXT,10,(LPARAM)ch1);
//::SendMessage(m_edit1.m_hWnd,WM_GETTEXT,10,(LPARAM)ch1);
//GetDlgItem(IDC_EDIT1)->SendMessage(WM_GETTEXT,10,(LPARAM)ch1);
m_edit1.SendMessage(WM_GETTEXT,10,(LPARAM)ch1);
m_edit2.SendMessage(WM_GETTEXT,10,(LPARAM)ch2);

num1=atoi(ch1);
num2=atoi(ch2);
num3=num1+num2;
itoa(num3,ch3,10);

m_edit3.SendMessage(WM_SETTEXT,0,(LPARAM)ch3);*/

7、int num1,num2,num3;
char ch1[10],ch2[10],ch3[10];

SendDlgItemMessage(IDC_EDIT1,WM_GETTEXT,10,(LPARAM)ch1);
SendDlgItemMessage(IDC_EDIT2,WM_GETTEXT,10,(LPARAM)ch2);

num1=atoi(ch1);
num2=atoi(ch2);
num3=num1+num2;
itoa(num3,ch3,10);

SendDlgItemMessage(IDC_EDIT3,WM_SETTEXT,0,(LPARAM)ch3);
SendDlgItemMessage(IDC_EDIT3,EM_SETSEL,0,-1);
m_edit3.SetFocus();