在C语言Windows编程中怎样判断编辑框中没有内容时报错，最好给出代码，谢谢！

Answer 1

窗口过程核心代码，测试环境vc6  _MBCS

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

...

     static HWND hEdit;

static HWND hBtn;

TCHAR buf[1000];

     switch (message)

     {

     case WM_CREATE:

          //PlaySound (TEXT ("hellowin.wav"), NULL, SND_FILENAME | SND_ASYNC) ;

         hEdit = CreateWindowEx(WS_EX_CLIENTEDGE, TEXT("EDIT"), TEXT(""), 

WS_CHILDWINDOW, 100, 100, 200, 30,

hwnd, NULL, NULL, NULL);

ShowWindow(hEdit, SW_SHOW);

hBtn = CreateWindowEx(WS_EX_WINDOWEDGE, TEXT("BUTTON"), TEXT("按钮"), 

WS_CHILDWINDOW, 340, 100, 100, 30,

hwnd, NULL, NULL, NULL);

ShowWindow(hBtn, SW_SHOW);

return 0 ;

     case WM_COMMAND:

if(lParam == (LPARAM)hBtn)

{

GetWindowText(hEdit, buf, 1000);

if(!strlen(buf))

{

MessageBox(hwnd, TEXT("文本框为空!"), TEXT("错误"), MB_OK);

}

}

return 0;

 ....

     case WM_DESTROY:

 DestroyWindow(hEdit);

 DestroyWindow(hBtn);

          PostQuitMessage (0) ;

          return 0 ;

     }

     return DefWindowProc (hwnd, message, wParam, lParam) ;

}

再来几个mfc的

void CMfcdlg2014Dlg::OnButton1() 

{

// TODO: Add your control notification handler code here

CString s;

GetDlgItemText(IDC_EDIT1, s);

if(s.IsEmpty())

{

MessageBox(_T("文本框为空!"));

}

}

void CMfcdlg2014Dlg::OnButton2() 

{

// TODO: Add your control notification handler code here

TCHAR buf[1000];

GetDlgItemText(IDC_EDIT1, buf, 1000);

if(!strlen(buf))

{

AfxMessageBox(_T("Edit1为空!"));

}

}

void CMfcdlg2014Dlg::OnButton3() 

{

// TODO: Add your control notification handler code here

CWnd *p = GetDlgItem(IDC_EDIT1);

CString s;

((CEdit*)p)->GetWindowText(s);

if(s.IsEmpty())

{

MessageBox(_T("文本框为空!"));

}

}

void CMfcdlg2014Dlg::OnButton4() 

{

// TODO: Add your control notification handler code here

TCHAR buf[1000];

::GetDlgItemText(m_hWnd, IDC_EDIT1, buf, 1000);

if(!strlen(buf))

{

AfxMessageBox(_T("Edit1为空!"));

}

}