Image

ImageFieldMergingArgs.Image property

Specifies the image that the mail merge engine must insert into the document.

public Image Image { get; set; }

Examples

Shows how to use a callback to customize image merging logic.

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

            // Insert a MERGEFIELD that will accept images from a source during a mail merge. Use the field code to reference
            // a column in the data source which contains local system filenames of images we wish to use in the mail merge.
            DocumentBuilder builder = new DocumentBuilder(doc);
            FieldMergeField field = (FieldMergeField)builder.InsertField("MERGEFIELD Image:ImageColumn");

            // In this case, the field expects the data source to have such a column named "ImageColumn".
            Assert.That(field.FieldName, Is.EqualTo("Image:ImageColumn"));

            // Filenames can be lengthy, and if we can find a way to avoid storing them in the data source,
            // we may considerably reduce its size.
            // Create a data source that refers to images using short names.
            DataTable dataTable = new DataTable("Images");
            dataTable.Columns.Add(new DataColumn("ImageColumn"));
            dataTable.Rows.Add("Dark logo");
            dataTable.Rows.Add("Transparent logo");

            // Assign a merging callback that contains all logic that processes those names,
            // and then execute the mail merge. 
            doc.MailMerge.FieldMergingCallback = new ImageFilenameCallback();
            doc.MailMerge.Execute(dataTable);

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

        /// <summary>
        /// Contains a dictionary that maps names of images to local system filenames that contain these images.
        /// If a mail merge data source uses one of the dictionary's names to refer to an image,
        /// this callback will pass the respective filename to the merge destination.
        /// </summary>
        private class ImageFilenameCallback : IFieldMergingCallback
        {
            public ImageFilenameCallback()
            {
                mImageFilenames = new Dictionary<string, string>();
                mImageFilenames.Add("Dark logo", ImageDir + "Logo.jpg");
                mImageFilenames.Add("Transparent logo", ImageDir + "Transparent background logo.png");
            }

            void IFieldMergingCallback.FieldMerging(FieldMergingArgs args)
            {
                throw new NotImplementedException();
            }

            void IFieldMergingCallback.ImageFieldMerging(ImageFieldMergingArgs args)
            {
                if (mImageFilenames.ContainsKey(args.FieldValue.ToString()))
                {
#if NET461_OR_GREATER || JAVA
                    args.Image = Image.FromFile(mImageFilenames[args.FieldValue.ToString()]);
#elif NET5_0_OR_GREATER
                    args.Image = SKBitmap.Decode(mImageFilenames[args.FieldValue.ToString()]);
                    args.ImageFileName = mImageFilenames[args.FieldValue.ToString()];
#endif
                }

                Assert.That(args.Image, Is.Not.Null);
            }

            private readonly Dictionary<string, string> mImageFilenames;
        }

See Also

ImageFieldMergingArgs.ImageFileName