插入Checkboxes、文本输入或图像

合并引擎将文档作为输入，在其中查找MERGEFIELD字段，并将其替换为从数据源获取的数据。 通常，插入纯文本和HTML，但Aspose.Words用户也可以生成处理Mail Merge字段更不寻常的情况的文档。

强大的Aspose.Words功能允许您扩展Mail Merge进程:

• 在mail merge期间将checkboxes和文本输入表单字段插入文档
• 从任何自定义存储（文件，BLOB字段等）插入图像。)

在Mail Merge期间插入Checkboxes和文本输入

有时需要执行Mail Merge操作，以便在合并字段中不是替换文本，而是替换checkbox或文本输入字段。 尽管这不是最常见的情况，但它对于某些任务来说非常方便。

Word文档的以下屏幕截图显示了具有合并字段的模板:

下面Word文档的此屏幕截图显示了已经生成的文档:

请注意，某些字段被替换为纯文本，某些字段被替换为checkbox表单字段，Subject字段被替换为文本输入字段。

下面的代码示例演示如何在mail merge期间将checkboxes和输入文本字段插入到文档中:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
Document doc = new Document(getMyDir() + "Mail merge destinations - Fax.docx");

// Setup mail merge event handler to do the custom work.
doc.getMailMerge().setFieldMergingCallback(new HandleMergeField());
// Trim trailing and leading whitespaces mail merge values.
doc.getMailMerge().setTrimWhitespaces(false);

String[] fieldNames = {
    "RecipientName", "SenderName", "FaxNumber", "PhoneNumber",
    "Subject", "Body", "Urgent", "ForReview", "PleaseComment"
};

Object[] fieldValues = {
    "Josh", "Jenny", "123456789", "", "Hello",
    "<b>HTML Body Test message 1</b>", true, false, true
};

doc.getMailMerge().execute(fieldNames, fieldValues);

doc.save(getArtifactsDir() + "WorkingWithFields.MailMergeFormFields.docx");

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
private static class HandleMergeField implements IFieldMergingCallback
{
    /// <summary>
    /// This handler is called for every mail merge field found in the document,
    /// for every record found in the data source.
    /// </summary>
    public void /*IFieldMergingCallback.*/fieldMerging(FieldMergingArgs e) throws Exception
    {
        if (mBuilder == null)
            mBuilder = new DocumentBuilder(e.getDocument());

        // We decided that we want all boolean values to be output as check box form fields.
        if (e.getFieldValue() instanceof /*boolean*/Boolean)
        {
            // Move the "cursor" to the current merge field.
            mBuilder.moveToMergeField(e.getFieldName());

            String checkBoxName = MessageFormat.format("{0}{1}", e.getFieldName(), e.getRecordIndex());

            mBuilder.insertCheckBox(checkBoxName, (Boolean) e.getFieldValue(), 0);

            return;
        }

        switch (e.getFieldName())
        {
            case "Body":
                mBuilder.moveToMergeField(e.getFieldName());
                mBuilder.insertHtml((String) e.getFieldValue());
                break;
            case "Subject":
            {
                mBuilder.moveToMergeField(e.getFieldName());
                String textInputName = MessageFormat.format("{0}{1}", e.getFieldName(), e.getRecordIndex());
                mBuilder.insertTextInput(textInputName, TextFormFieldType.REGULAR, "", (String) e.getFieldValue(), 0);
                break;
            }
        }
    }

    public void imageFieldMerging(ImageFieldMergingArgs args)
    {
        args.setImageFileName("Image.png");
        args.getImageWidth().setValue(200.0);
        args.setImageHeight(new MergeFieldImageDimension(200.0, MergeFieldImageDimensionUnit.PERCENT));
    }

    private DocumentBuilder mBuilder;
}

在Mail Merge期间插入图像

执行Mail Merge操作时，可以使用特殊的imageMail Merge字段将数据库中的图像插入到文档中。 ImageMail Merge字段是一个名为Image:MyFieldName的合并字段。

从数据库中插入图像

在mail merge期间，当在文档中遇到图像Mail Merge字段时，会触发FieldMergingCallback事件。 您可以响应此事件以将文件名、流或图像对象返回到Mail Merge引擎，以便将其插入到文档中。

下面的代码示例演示如何将数据库BLOB字段中存储的图像插入到报表中:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
public void mailMergeImageFromBlob() throws Exception
{
    Document doc = new Document(getMyDir() + "Mail merge destination - Northwind employees.docx");

    doc.getMailMerge().setFieldMergingCallback(new HandleMergeImageFieldFromBlob());

    Class.forName("net.ucanaccess.jdbc.UcanaccessDriver");
    String connString = "jdbc:ucanaccess://" + getDatabaseDir() + "Northwind.mdb";

    Connection connection = DriverManager.getConnection(connString, "Admin", "");

    Statement statement = connection.createStatement();
    ResultSet resultSet = statement.executeQuery("SELECT * FROM Employees");

    DataTable dataTable = new DataTable(resultSet, "Employees");
    IDataReader dataReader = new DataTableReader(dataTable);

    doc.getMailMerge().executeWithRegions(dataReader, "Employees");

    connection.close();
    
    doc.save(getArtifactsDir() + "WorkingWithFields.MailMergeImageFromBlob.docx");
}

public static class HandleMergeImageFieldFromBlob implements IFieldMergingCallback
{
    public void fieldMerging(FieldMergingArgs args)
    {
        // Do nothing.
    }

    /// <summary>
    /// This is called when mail merge engine encounters Image:XXX merge field in the document.
    /// You have a chance to return an Image object, file name, or a stream that contains the image.
    /// </summary>
    public void imageFieldMerging(ImageFieldMergingArgs e) throws Exception
    {
        // The field value is a byte array, just cast it and create a stream on it.
        ByteArrayInputStream imageStream = new ByteArrayInputStream((byte[]) e.getFieldValue());
        // Now the mail merge engine will retrieve the image from the stream.
        e.setImageStream(imageStream);
    }
}

在Mail Merge期间设置图像属性

在合并图像合并字段时，有时可能需要控制各种图像属性，例如WrapType。

目前，使用ImageFieldMergingArgs只能分别设置图像宽度或高度属性。 为了解决这个问题，Aspose.Words提供了Shape属性，这有助于完全控制插入的图像或任何其他形状。

下面的代码示例演示如何设置各种图像属性:

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

builder.writeln("{{#foreach example}}");
builder.writeln("{{Image(126pt;126pt):stempel}}");
builder.writeln("{{/foreach example}}");

doc.getMailMerge().setUseNonMergeFields(true);
doc.getMailMerge().setTrimWhitespaces(true);
doc.getMailMerge().setUseWholeParagraphAsRegion(false);
doc.getMailMerge().setCleanupOptions(MailMergeCleanupOptions.REMOVE_EMPTY_TABLE_ROWS
        | MailMergeCleanupOptions.REMOVE_CONTAINING_FIELDS
        | MailMergeCleanupOptions.REMOVE_UNUSED_REGIONS
        | MailMergeCleanupOptions.REMOVE_UNUSED_FIELDS);

doc.getMailMerge().setFieldMergingCallback(new ImageFieldMergingHandler());
doc.getMailMerge().executeWithRegions(new DataSourceRoot());

doc.save(getArtifactsDir() + "WorkingWithFields.MailMergeImageField.docx");

// For complete examples and data files, please go to https://github.com/aspose-words/Aspose.Words-for-Java
private static class ImageFieldMergingHandler implements IFieldMergingCallback
{
    public void fieldMerging(FieldMergingArgs args)
    {
        //  Implementation is not required.
    }

    public void imageFieldMerging(ImageFieldMergingArgs args) throws Exception
    {
        Shape shape = new Shape(args.getDocument(), ShapeType.IMAGE);
        {
            shape.setWidth(126.0); shape.setHeight(126.0); shape.setWrapType(WrapType.SQUARE);
        }

        shape.getImageData().setImage(getMyDir() + "Mail merge image.png");

        args.setShape(shape);
    }
}