IFieldMergingCallbackImageFieldMerging Method

Called when the Aspose.Words mail merge engine is about to insert an image into a merge field.

Namespace:  Aspose.Words.MailMerging
Assembly:  Aspose.Words (in Aspose.Words.dll) Version: 20.7.0

Syntax

void ImageFieldMerging(
	ImageFieldMergingArgs args
)

Parameters

args
Type: Aspose.Words.MailMergingImageFieldMergingArgs

Examples

Shows how to insert images stored in a database BLOB field into a report.
public void ImageFromBlob()
{
    Document doc = new Document(MyDir + "Mail merge destination - Northwind employees.docx");

    // Set up the event handler for image fields
    doc.MailMerge.FieldMergingCallback = new HandleMergeImageFieldFromBlob();

    // Open a database connection
    string connString = $"Provider=Microsoft.Jet.OLEDB.4.0;Data Source={DatabaseDir + "Northwind.mdb"};";
    string query = "SELECT FirstName, LastName, Title, Address, City, Region, Country, PhotoBLOB FROM Employees";

    using (OleDbConnection conn = new OleDbConnection(connString))
    {
        conn.Open();

        // Open the data reader. It needs to be in the normal mode that reads all record at once
        OleDbCommand cmd = new OleDbCommand(query, conn);
        IDataReader dataReader = cmd.ExecuteReader();

        // Perform mail merge
        doc.MailMerge.ExecuteWithRegions(dataReader, "Employees");
    }

    doc.Save(ArtifactsDir + "MailMergeEvent.ImageFromBlob.docx");
}

private class HandleMergeImageFieldFromBlob : IFieldMergingCallback
{
    void IFieldMergingCallback.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>
    void IFieldMergingCallback.ImageFieldMerging(ImageFieldMergingArgs e)
    {
        // The field value is a byte array, just cast it and create a stream on it
        MemoryStream imageStream = new MemoryStream((byte[])e.FieldValue);
        // Now the mail merge engine will retrieve the image from the stream
        e.ImageStream = imageStream;
    }
}

See Also