ImageFieldMergingArgs Class

public class ImageFieldMergingArgs : FieldMergingArgsBase

Public Class ImageFieldMergingArgs
	Inherits FieldMergingArgsBase

public ref class ImageFieldMergingArgs : public FieldMergingArgsBase

type ImageFieldMergingArgs =  
    class
        inherit FieldMergingArgsBase
    end

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.ACE.OLEDB.12.0;Data Source=" + DatabaseDir + "Northwind.mdb";
    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("SELECT * FROM Employees", conn);
    IDataReader dataReader = cmd.ExecuteReader();

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

    // Close the database
    conn.Close();

    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;
    }
}

public void MergeFieldImageDimension()
{
    Document doc = new Document();

    // Insert a merge field where images will be placed during the mail merge
    DocumentBuilder builder = new DocumentBuilder(doc);
    builder.InsertField("MERGEFIELD Image:ImageColumn");

    // Create a data table for the mail merge
    // The name of the column that contains our image filenames needs to match the name of our merge field
    DataTable dataTable = CreateDataTable("Images", "ImageColumn",
        new string[]
        {
            ImageDir + "Logo.jpg",
            ImageDir + "Transparent background logo.png",
            ImageDir + "Enhanced Windows MetaFile.emf"
        });

    doc.MailMerge.FieldMergingCallback = new MergedImageResizer(200, 200, MergeFieldImageDimensionUnit.Point);
    doc.MailMerge.Execute(dataTable);

    doc.UpdateFields();
    doc.Save(ArtifactsDir + "Field.MERGEFIELD.ImageDimension.docx");
}

/// <summary>
/// Creates a data table with a single column.
/// </summary>
private static DataTable CreateDataTable(string tableName, string columnName, string[] columnContents)
{
    DataTable dataTable = new DataTable(tableName);
    dataTable.Columns.Add(new DataColumn(columnName));

    foreach (string s in columnContents)
    {
        DataRow dataRow = dataTable.NewRow();
        dataRow[0] = s;
        dataTable.Rows.Add(dataRow);
    }

    return dataTable;
}

/// <summary>
/// Sets the size of all mail merged images to one defined width and height.
/// </summary>
private class MergedImageResizer : IFieldMergingCallback
{
    public MergedImageResizer(double imageWidth, double imageHeight, MergeFieldImageDimensionUnit unit)
    {
        mImageWidth = imageWidth;
        mImageHeight = imageHeight;
        mUnit = unit;
    }

    public void FieldMerging(FieldMergingArgs e)
    {
        throw new NotImplementedException();
    }

    public void ImageFieldMerging(ImageFieldMergingArgs args)
    {
        args.ImageFileName = args.FieldValue.ToString();
        args.ImageWidth = new MergeFieldImageDimension(mImageWidth, mUnit);
        args.ImageHeight = new MergeFieldImageDimension(mImageHeight, mUnit);

        Assert.AreEqual(mImageWidth, args.ImageWidth.Value);
        Assert.AreEqual(mUnit, args.ImageWidth.Unit);
        Assert.AreEqual(mImageHeight, args.ImageHeight.Value);
        Assert.AreEqual(mUnit, args.ImageHeight.Unit);
    }

    private readonly double mImageWidth;
    private readonly double mImageHeight;
    private readonly MergeFieldImageDimensionUnit mUnit;
}