如何在 Aspose Word 文档中显示 SQL Server 数据库图像 base64

Question

我是 Aspose 的新手，遇到以下问题：

我在 SQL Server 2008 数据库中有图像，存储为 Base64 字符串。我想使用 Aspose 在 Word 文档中显示它们。

我已成功导出其他数据，但无法显示图像。谁能帮帮我？

提前感谢您的支持。

这是我的代码：

private Document createDocs(Guid ? ID)
{
    Document doc = new Document(HostingEnvironment.MapPath("~/Content/Template.doc"));
    DataTable Order = ExecuteDataTable(inspID);

    if (!(Order == null))
    {
        doc.MailMerge.FieldMergingCallback = new HandleMergeImageFieldFromBlob();
        doc.MailMerge.ExecuteWithRegions(Order);
    }

    return doc;
}

public DataTable ExecuteDataTable(Guid? ID)
{
    var connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyStringConnection"];

    SqlConnection Conn = new SqlConnection(connectionString.ConnectionString);

    try
    {
        Conn.Open();

        SqlCommand cmd = new SqlCommand("SELECT * FROM blahblah, Conn);
        cmd.Parameters.Add("@ID", SqlDbType.UniqueIdentifier).Value = ID;

        SqlDataAdapter da = new SqlDataAdapter(cmd);
        da.SelectCommand = cmd;

        DataTable table = new DataTable();
        da.Fill(table);

        return table;
    }
    finally
    {
        if (!(Conn == null))
        {
            Conn.Close();
        }
    }
}

private void SendToBrowser (Document doc, string outputFormat, Page page)
{
    MemoryStream stream = new MemoryStream();
    doc.Save(stream, SaveFormat.Doc);

    page.Response.Clear();
    page.Response.ClearHeaders();
    page.Response.ClearContent();
    page.Response.ContentType = "application/doc";
    page.Response.AddHeader("content-disposition", "attachment; filename=base_file.doc");

    byte[] bytes = stream.GetBuffer();

    page.Response.BinaryWrite(bytes);
    page.Response.End();
}

public 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.
        var imageStream = new MemoryStream((byte[])e.FieldValue);

        // Now the mail merge engine will retrieve the image from the stream.
        e.ImageStream = imageStream;
    }
}

Answer 1

要在 Word 中将图像邮件合并字段插入到文档中，请选择插入/字段命令，然后选择 MergeField 并键入 Image:MyFieldName。以下代码示例显示了如何使用 Base64 图像执行邮件合并操作。请检查 IFieldMergingCallback.ImageFieldMerging 的修改代码。

public void mailmerge()
{
    string base64String;
    using (Image image = Image.FromFile(MyDir + @"image.png"))
    {
        using (MemoryStream m = new MemoryStream())
        {
            image.Save(m, image.RawFormat);
            byte[] imageBytes = m.ToArray();

            // Convert byte[] to Base64 String
            base64String = Convert.ToBase64String(imageBytes);
        }
    }

    DataTable dt = new DataTable();
    dt.Columns.Add("ImageData", typeof(string));

    DataRow row1 = dt.NewRow();
    row1["ImageData"] = base64String;
    dt.Rows.Add(row1);

    Document doc = new Document(MyDir + "in.docx");
    doc.MailMerge.FieldMergingCallback = new HandleMergeImageFieldFromBlob();
    doc.MailMerge.Execute(dt);
    doc.Save(MyDir + "Out.docx");
}

public 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)
    {
        var imageStream = new MemoryStream((byte[])Convert.FromBase64String(e.FieldValue.ToString()));

        // Now the mail merge engine will retrieve the image from the stream.
        e.ImageStream = imageStream;
    }
}

我与 Aspose 合作，担任开发人员传道者。