Cara Menerapkan Pemformatan Khusus selama Mail Merge

Kelas MailMerge menyediakan dua peristiwa yang bisa sangat berguna dalam memperluas kemampuan Mail Merge. Properti setFieldMergingCallback(IFieldMergingCallback) menerima kelas yang mengimplementasikan metode fieldMerging(FieldMergingArgs) dan imageFieldMerging(ImageFieldMergingArgs). Ini dapat digunakan untuk mengimplementasikan kontrol kustom atas proses Mail Merge.

Peristiwa fieldMerging(FieldMergingArgs) terjadi selama Mail Merge saat bidang Mail Merge sederhana ditemukan dalam dokumen. Ini memberikan kontrol lebih lanjut atas Mail Merge dan Anda dapat melakukan tindakan apa pun saat peristiwa tersebut terjadi. Metode ini dibungkus dalam kelas yang mengimplementasikan antarmuka IFieldMergingCallBack dan menerima objek FieldMergingArgs yang menyediakan data untuk peristiwa terkait.

Contoh kode yang diberikan di bawah ini mendemonstrasikan cara menerapkan logika khusus dalam peristiwa MergeField untuk menerapkan pemformatan sel.

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
public class ApplyCustomFormattingDuringMailMerge {

    private static final String dataDir = Utils.getSharedDataDir(ApplyCustomFormattingDuringMailMerge.class) + "MailMerge/";

    public static void main(String[] args) throws Exception {
        Document doc = new Document(dataDir + "MailMerge.AlternatingRows.doc");

        // Add a handler for the MergeField event.
        doc.getMailMerge().setFieldMergingCallback(new HandleMergeFieldAlternatingRows());

        // Execute mail merge with regions.
        DataTable dataTable = getSuppliersDataTable();
        doc.getMailMerge().executeWithRegions(dataTable);

        doc.save(dataDir + "MailMerge.AlternatingRows Out.doc");
    }

    /**
     * Returns true if the value is odd; false if the value is even.
     */
    public static boolean isOdd(int value) throws Exception {
        return (value % 2 != 0);
    }

    /**
     * Create DataTable and fill it with data. In real life this DataTable
     * should be filled from a database.
     */
    private static DataTable getSuppliersDataTable() throws Exception {
        java.sql.ResultSet resultSet = createCachedRowSet(new String[]{"CompanyName", "ContactName"});

        for (int i = 0; i < 10; i++)
            addRow(resultSet, new String[]{"Company " + Integer.toString(i), "Contact " + Integer.toString(i)});

        return new DataTable(resultSet, "Suppliers");
    }

    /**
     * A helper method that creates an empty Java disconnected ResultSet with
     * the specified columns.
     */
    private static ResultSet createCachedRowSet(String[] columnNames) throws Exception {
        RowSetMetaDataImpl metaData = new RowSetMetaDataImpl();
        metaData.setColumnCount(columnNames.length);
        for (int i = 0; i < columnNames.length; i++) {
            metaData.setColumnName(i + 1, columnNames[i]);
            metaData.setColumnType(i + 1, java.sql.Types.VARCHAR);
        }

        CachedRowSet rowSet = RowSetProvider.newFactory().createCachedRowSet();
        ;
        rowSet.setMetaData(metaData);

        return rowSet;
    }

    /**
     * A helper method that adds a new row with the specified values to a
     * disconnected ResultSet.
     */
    private static void addRow(ResultSet resultSet, String[] values) throws Exception {
        resultSet.moveToInsertRow();

        for (int i = 0; i < values.length; i++)
            resultSet.updateString(i + 1, values[i]);

        resultSet.insertRow();

        // This "dance" is needed to add rows to the end of the result set properly.
        // If I do something else then rows are either added at the front or the result
        // set throws an exception about a deleted row during mail merge.
        resultSet.moveToCurrentRow();
        resultSet.last();
    }
}

class HandleMergeFieldAlternatingRows implements IFieldMergingCallback {
    /**
     * Called for every merge field encountered in the document. We can either
     * return some data to the mail merge engine or do something else with the
     * document. In this case we modify cell formatting.
     */
    public void fieldMerging(FieldMergingArgs e) throws Exception {
        if (mBuilder == null)
            mBuilder = new DocumentBuilder(e.getDocument());

        // This way we catch the beginning of a new row.
        if (e.getFieldName().equals("CompanyName")) {
            // Select the color depending on whether the row number is even or odd.
            Color rowColor;
            if (ApplyCustomFormattingDuringMailMerge.isOdd(mRowIdx))
                rowColor = new Color(213, 227, 235);
            else
                rowColor = new Color(242, 242, 242);

            // There is no way to set cell properties for the whole row at the moment,
            // so we have to iterate over all cells in the row.
            for (int colIdx = 0; colIdx < 4; colIdx++) {
                mBuilder.moveToCell(0, mRowIdx, colIdx, 0);
                mBuilder.getCellFormat().getShading().setBackgroundPatternColor(rowColor);
            }

            mRowIdx++;
        }
    }

    public void imageFieldMerging(ImageFieldMergingArgs args) throws Exception {
        // Do nothing.
    }

    private DocumentBuilder mBuilder;
    private int mRowIdx;
}