使用DialogBoxIndirect时，如何关闭对话框时用户输入的文本？

Question

I'm using DialogBoxIndirect() to create a modal dialog in memory. One of the controls that I'm adding to the dialog has the EDIT class, so users can type in information in the dialog. When the dialog is closed, how do I figure out what the user typed into the EDIT field? I don't have an HWND for the EDIT field or the dialog itself, all I have is the id. The only way I know of is GetWindowText(), but that requires an HWND.

Code snippet:

//-----------------------
// Define Edit Input
//-----------------------
lpw = lpwAlign(lpw);    // Align DLGITEMTEMPLATE on DWORD boundary
lpdit = (LPDLGITEMTEMPLATE)lpw;
lpdit->x = 10; lpdit->y = 10;
lpdit->cx = 150; lpdit->cy = 25;
lpdit->id = ID_TEXT2;       // Text input
lpdit->dwExtendedStyle = WS_EX_CLIENTEDGE;
lpdit->style = WS_CHILD | WS_VISIBLE;
lpw = (LPWORD)(lpdit + 1);
*lpw++ = 0xFFFF;
*lpw++ = 0x0081;        // Edit class
lpwsz = (LPWSTR)lpw;
nchar = MultiByteToWideChar(CP_ACP, 0, lpszMessage, -1, lpwsz, 50);
lpw += nchar;
*lpw++ = 0;             // No creation data

//-----------------------
// Define an OK button.
//-----------------------
lpw = lpwAlign(lpw);    // Align DLGITEMTEMPLATE on DWORD boundary
lpdit = (LPDLGITEMTEMPLATE)lpw;
lpdit->x = 10; lpdit->y = 40;
lpdit->cx = 35; lpdit->cy = 13;
lpdit->id = IDOK;       // OK button identifier
lpdit->style = WS_CHILD | WS_VISIBLE | BS_DEFPUSHBUTTON;
lpw = (LPWORD)(lpdit + 1);
*lpw++ = 0xFFFF;
*lpw++ = 0x0080;        // Button class
lpwsz = (LPWSTR)lpw;
nchar = MultiByteToWideChar(CP_ACP, 0, "OK", -1, lpwsz, 50);
lpw += nchar;
*lpw++ = 0;             // No creation data

GlobalUnlock(hgbl);
ret = DialogBoxIndirect(hinst, (LPDLGTEMPLATE)hgbl, GetFocus(), (DLGPROC)GenericDlgProc);
// How do I get the text here, that the user entered into control id ID_TEXT2?

Answer 1

You can use GetDlgItemText() to get text from an edit control using its ID; basically what this does is a GetDlgItem() followed by a GetWindowText() all in one useful function call.

However by the time your DialogBoxIndirect() call has returned it's too late to do this - the dialog is gone, and the controls along with it. You can't read a control's value once it's been destroyed.

The usual way to deal with this is to handle WM_DESTROY in your DialogProc , and save the control values there (alternatively, if you have an OK and a Cancel button, you might do this in the WM_COMMAND handler for IDOK instead).