void Cdlg::OnButton1()
{
// TOD Add your control notification handler code here
CString str;
if(GetDlgItemText(IDC_BUTTON1,str),str=="缩小")
{

SetDlgItemText(IDC_BUTTON1,"扩张");

}
else{

SetDlgItemText(IDC_BUTTON1,"缩小"); }
static CRect rectold;
static CRect rectnew;
CRect p;
GetWindowRect(&rectold);
GetDlgItem(IDC_PIC)->GetWindowRect(&p);
rectnew.top=rectold.top;
rectnew.left=rectold.left;
rectnew.right=rectold.right;
rectnew.bottom=p.bottom;

if(str=="缩小") { SetWindowPos(NULL,0,0,rectnew.Width(),rectnew.Height(),
SWP_NOMOVE|SWP_NOZORDER); }
else
SetWindowPos(NULL,0,0,rectold.Width(),rectold.Height(),
SWP_NOMOVE|SWP_NOZORDER);}

为什么按下缩小之后，再按就不扩大了那

你第一次点button后,看看两个rect是多少,大的是rectold,小的是rectnew.
第2次点的时候呢？

GetWindowRect(&rectold);
GetDlgItem(IDC_PIC)->GetWindowRect(&p);
rectnew.top=rectold.top;
rectnew.left=rectold.left;
rectnew.right=rectold.right;
rectnew.bottom=p.bottom;

那请问怎么改啊