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 MapDialogRect

The MapDialogRect function converts the specified dialog box units to screen units (pixels). The function replaces the coordinates in the specified RECT structure with the converted coordinates, which allows the structure to be used to create a dialog box or position a control within a dialog box.

Syntax

    BOOL MapDialogRect(  
        HWND hDlg,
        LPRECT lpRect
    );

Parameters

• hDlg
  [in] Handle to a dialog box. This function accepts only handles returned by one of the dialog box creation functions; handles for other windows are not valid.
• lpRect
  [in, out] Pointer to a RECT structure that contains the dialog box coordinates to be converted.

Return Value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The MapDialogRect function assumes that the initial coordinates in the RECT structure represent dialog box units. To convert these coordinates from dialog box units to pixels, the function retrieves the current horizontal and vertical base units for the dialog box, then applies the following formulas:

left   = MulDiv(left,   baseunitX, 4);
right  = MulDiv(right,  baseunitX, 4);
top    = MulDiv(top,    baseunitY, 8);
bottom = MulDiv(bottom, baseunitY, 8);

If the dialog box template has the DS_SETFONT or DS_SHELLFONT style, the base units are the average width and height, in pixels, of the characters in the font specified by the template.

Function Information

• Minimum DLL Version user32.dll
• Header Declared in Winuser.h, include Windows.h
• Import library User32.lib
• Minimum operating systems Windows 95, Windows NT 3.1
• Unicode Implemented as Unicode version.

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Notebook exported on Monday, 7 July 2008, 18:56:50 PM Eastern Daylight Time