Before using the MLM_EXPORT message the number of characters to export needs to be determined. The MLM_QUERYFORMATTEXTLENGTH message is used to determine the number of characters to be copied from the MLE to the buffer (including LF and CR) and to allocate the room in the buffer. MLM_EXPORT is then used to export the MLE text into the buffer.

Note: The MLM_QUERYTEXTLENGTH message does not consider the CR and LF characters as the MLM_QUERYFORMATTEXTLENGTH message does.

The following code fragment reads text from a file to a buffer, then imports the text to an MLE field:

HWND  hwndMle;
CHAR  szMleBuf[512];
IPT   lOffset = 0;
PSZ   pszTextFile;
HFILE hf;
ULONG cbCopied;
ULONG ulAction;
ULONG cbBytesRead;

/* Obtain a file name from the user */

/* Open the file */
DosOpen(pszTextFile,
        &hf,
        &ulAction,
        0,
        FILE_NORMAL,
        FILE_OPEN |
        FILE_CREATE,
        OPEN_ACCESS_READONLY |
        OPEN_SHARE_DENYNONE,
        NULL);

/* Zero-fill the buffer using memset, a C run-time function */
memset(szMleBuf, 0, sizeof(szMleBuf));

/* Set the MLE import-export buffer */
WinSendMsg(hwndMle,
           MLM_SETIMPORTEXPORT,
           MPFROMP(szMleBuf),
           MPFROMSHORT((USHORT) sizeof(szMleBuf)));

/**********************************************************************/
/*  Read the text from the file to the buffer,                        */
/*  then import it to the MLE.                                        */
/**********************************************************************/

do {
     DosRead(hf,
             szMleBuf,
             sizeof(szMleBuf),
             &cbBytesRead);

     cbCopied = (ULONG) WinSendMsg(hwndMle,
                        MLM_IMPORT,
                        MPFROMP( &lOffset),
                        MPFROMP(&cbBytesRead));
   } while (cbCopied);

/* Close the file */
DosClose(hf);

To export MLE text, an application sends the MLM_EXPORT message to the MLE control. Like MLM_IMPORT, the MLM_EXPORT message takes the plOffset and cbCopy parameters. The plOffset parameter is a pointer to a variable that specifies the offset to the first character to export. A value of -1 specifies the current cursor position. On return, the variable contains the offset to the first character in the MLE field not copied to the buffer. The cbCopy parameter is a pointer to a variable that specifies the number of bytes to export. On return, this variable equals 0 if the number of characters actually copied does not exceed the number specified to be copied. The following code fragment shows how to export text from an MLE field, then store the text in a file:

HWND  hwndMle;
CHAR  szMleBuf[512];
IPT   lOffset = 0;
PSZ   pszTextFile;
HFILE hf;

ULONG cbCopied;
ULONG ulAction;
ULONG cbBytesWritten;
ULONG cbCopy;

/* Zero-fill the buffer using memset, a C run-time function */
memset(szMleBuf, 0, sizeof(szMleBuf));

/* Set the MLE import-export buffer */
WinSendMsg(hwndMle,
           MLM_SETIMPORTEXPORT,
           MPFROMP(szMleBuf),
           MPFROMSHORT ((USHORT) sizeof(szMleBuf)));

   .
   .
   .

/* Obtain a filename from the user */
   .
   .
   .

/* Open the file */
DosOpen(pszTextFile,
        &hf,
        &ulAction,
        0,
        FILE_NORMAL,
        FILE_OPEN |
        FILE_CREATE,
        OPEN_ACCESS_WRITEONLY |
        OPEN_SHARE_DENYNONE,
        NULL);

/* Find out how much text is in the MLE */
cbCopy = (ULONG) WinSendMsg(hwndMle,
                            MLM_QUERYFORMATTEXTLENGTH,
                            MPFROMLONG(lOffset),
                            MPFROMLONG((-1)));

/* Copy the MLE text to the buffer */
cbCopied = (ULONG) WinSendMsg(hwndMle,
                              MLM_EXPORT,
                              MPFROMP(&lOffset),
                              MPFROMP(&cbCopy));

/* Write the contents of the buffer to the file */
DosWrite(hf,
         szMleBuf,
         sizeof(szMleBuf),
         &cbBytesWritten);

/* Close the file */
DosClose(hf);

---

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