C# WPF 将 richtextbox 中粘贴的 BitmapImage 转换为二进制

Question

我有一个 richtextbox，我计划将其保存到数据库中，该数据库可以加载回同一个 richtextbox。我让它正常工作，以便我可以将流文档保存为 DataFormats.XamlPackage，这样可以保存图像，但问题是文本不可搜索。使用 DataFormats.Xaml，我当然得到了文本，但没有图像。这些图像将由最终用户粘贴，而不是应用程序附带的图像。

我尝试使用 XamlWriter 将文本转换为 XML，然后分别从文档中获取图像并将它们作为二进制文件插入到 XML 中，但我似乎找不到将图像转换为二进制文件的方法。 .

有没有人知道如何将图像转换为二进制文件，与文本分开？

提前致谢!

GetImageByteArray() 是问题所在。

代码:

private void SaveXML()
{
            TextRange documentTextRange = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd);
            FlowDocument flowDocument = richTextBox.Document;
using (StringWriter stringwriter = new StringWriter())
                {
                    using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(stringwriter))
                    {
                        XamlWriter.Save(flowDocument, writer );
                    }

                    testRTF t = new testRTF();
                    t.RtfText = new byte[0];
                    t.RtfXML = GetImagesXML(flowDocument);
                    t.RtfFullText = stringwriter.ToString();
                    //save t to database
                }
                richTextBox.Document.Blocks.Clear();
}


private string GetImagesXML(FlowDocument flowDocument)
        {

            using (StringWriter stringwriter = new StringWriter())
            {
                using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(stringwriter))
                {

                    Type inlineType;
                    InlineUIContainer uic;
                    System.Windows.Controls.Image replacementImage;
                    byte[] bytes;
                    System.Text.ASCIIEncoding enc;

                    //loop through replacing images in the flowdoc with the byte versions
                    foreach (Block b in flowDocument.Blocks)
                    {
                        foreach (Inline i in ((Paragraph)b).Inlines)
                        {
                            inlineType = i.GetType();

                            if (inlineType == typeof(Run))
                            {
                                //The inline is TEXT!!!
                            }
                            else if (inlineType == typeof(InlineUIContainer))
                            {
                                //The inline has an object, likely an IMAGE!!!
                                uic = ((InlineUIContainer)i);

                                //if it is an image
                                if (uic.Child.GetType() == typeof(System.Windows.Controls.Image))
                                {
                                    //grab the image
                                    replacementImage = (System.Windows.Controls.Image)uic.Child;

                                    //get its byte array
                                    bytes = GetImageByteArray((BitmapImage)replacementImage.Source);
                                    //write the element
                                    writer.WriteStartElement("Image");
                                    //put the bytes into the tag
                                    enc = new System.Text.ASCIIEncoding();
                                    writer.WriteString(enc.GetString(bytes));
                                    //close the element
                                    writer.WriteEndElement();
                                }
                            }
                        }
                    }
                }

                return stringwriter.ToString();
            }
        }


//This function is where the problem is, i need a way to get the byte array
        private byte[] GetImageByteArray(BitmapImage bi)
        {
            byte[] result = new byte[0];
                    using (MemoryStream ms = new MemoryStream())
                    {
                        XamlWriter.Save(bi, ms);
                        //result = new byte[ms.Length];
                        result = ms.ToArray();
                    }
            return result;
}

更新

我想我可能终于找到了解决方案，我将在下面发布。它使用 BmpBitmapEncoder 和 BmpBitmapDecoder。这使我能够从位图图像中获取二进制文件，将其存储到数据库中，然后将其重新加载并将其显示回 FlowDocument 中。初步测试证明是成功的。出于测试目的，我绕过了我的数据库步骤，基本上是通过创建二进制文件来复制图像，然后获取二进制文件并将其转换为新图像并将其添加到 FlowDocument 中。唯一的问题是，当我尝试采用修改后的 FlowDocument 并使用 XamlWriter.Save 函数时，它在新创建的图像上出错，显示“无法序列化非公共(public)类型‘System.Windows.Media.Imaging.BitmapFrameDecode’”。这需要进一步调查。不过，我现在不得不让它一个人呆着。

private void SaveXML()
        {
            TextRange documentTextRange = new TextRange(richTextBox.Document.ContentStart, richTextBox.Document.ContentEnd);
            FlowDocument flowDocument = richTextBox.Document;

            string s = GetImagesXML(flowDocument);//temp
            LoadImagesIntoXML(s);

                using (StringWriter stringwriter = new StringWriter())
                {
                    using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(stringwriter))
                    {
                        XamlWriter.Save(flowDocument, writer );//Throws error here
                    }

                }
}

private string GetImagesXML(FlowDocument flowDocument)
        {
            string s= "";

            using (StringWriter stringwriter = new StringWriter())
            {


                    Type inlineType;
                    InlineUIContainer uic;
                    System.Windows.Controls.Image replacementImage;
                    byte[] bytes;
                    BitmapImage bi;

                    //loop through replacing images in the flowdoc with the byte versions
                    foreach (Block b in flowDocument.Blocks)
                    {
                        foreach (Inline i in ((Paragraph)b).Inlines)
                        {
                            inlineType = i.GetType();

                            if (inlineType == typeof(Run))
                            {
                                //The inline is TEXT!!!
                            }
                            else if (inlineType == typeof(InlineUIContainer))
                            {
                                //The inline has an object, likely an IMAGE!!!
                                uic = ((InlineUIContainer)i);

                                //if it is an image
                                if (uic.Child.GetType() == typeof(System.Windows.Controls.Image))
                                {
                                    //grab the image
                                    replacementImage = (System.Windows.Controls.Image)uic.Child;
                                    bi = (BitmapImage)replacementImage.Source;

                                    //get its byte array
                                    bytes = GetImageByteArray(bi);

                                    s = Convert.ToBase64String(bytes);//temp
                                }
                            }
                        }
                    }

                return s;
            }
        }

private byte[] GetImageByteArray(BitmapImage src)
        {
                MemoryStream stream = new MemoryStream();
                BmpBitmapEncoder encoder = new BmpBitmapEncoder();
                encoder.Frames.Add(BitmapFrame.Create((BitmapSource)src));
                encoder.Save(stream);
                stream.Flush();
            return stream.ToArray();
        }


private void LoadImagesIntoXML(string xml)
        {


            byte[] imageArr = Convert.FromBase64String(xml);
System.Windows.Controls.Image img = new System.Windows.Controls.Image()

MemoryStream stream = new MemoryStream(imageArr);
            BmpBitmapDecoder decoder = new BmpBitmapDecoder(stream, BitmapCreateOptions.None, BitmapCacheOption.Default);
            img.Source = decoder.Frames[0];
            img.Stretch = Stretch.None;

Paragraph p = new Paragraph();
            p.Inlines.Add(img);
            richTextBox.Document.Blocks.Add(p);
        }

Answer 1

好消息。我不得不在其他事情上工作一段时间，但这让我带着一双新的眼睛回来了。我很快意识到我可以结合我所知道的有效方法。我怀疑这个解决方案会赢得任何奖项，但它确实有效。我知道我可以使用 XamlReader 将 FlowDocument 包装为文本，保留图像元素但丢失图像数据。我还知道我可以使用 XamlFormat 将 FlowDocument 转换为二进制文件。所以我有了获取 FlowDocument 的想法，并使用我已经编写的函数来遍历它以查找图像，我获取每个图像，基本上克隆它并将克隆放入一个新的 FlowDocument 中。我采用现在包含单个图像的新 FlowDocument，将其转换为二进制文件，然后采用生成的二进制文件，将其转换为 base64 字符串并将其粘贴到原始 FlowDocument 中图像的标签属性中。这会将原始 FlowDocument 中的图像数据保留为文本。这样我就可以将带有图像数据(我称之为 SUBString 格式)的 FlowDocument 传递到 XamlReader 中以获取可搜索的文本。当它从数据库中出来时，我像往常一样从 Xaml 中提取 FlowDocument，然后遍历每个图像，使用 XamlFormat 从标记属性中提取数据，然后创建另一个克隆图像来为我的实际提供 Source 属性图片。我在下面提供了获取 SUBString 格式的步骤。

/// <summary>
    /// Returns a FlowDocument in SearchableText UI Binary (SUB)String format.
    /// </summary>
    /// <param name="flowDocument">The FlowDocument containing images/UI formats to be converted</param>
    /// <returns>Returns a string representation of the FlowDocument with images in base64 string in image tag property</returns>
    private string ConvertFlowDocumentToSUBStringFormat(FlowDocument flowDocument)
    {
        //take the flow document and change all of its images into a base64 string
        FlowDocument fd = TransformImagesTo64(flowDocument);

        //apply the XamlWriter to the newly transformed flowdocument
        using (StringWriter stringwriter = new StringWriter())
        {
            using (System.Xml.XmlWriter writer = System.Xml.XmlWriter.Create(stringwriter))
            {
                XamlWriter.Save(flowDocument, writer);
            }
            return stringwriter.ToString();
        }
    }

    /// <summary>
    /// Returns a FlowDocument with images in base64 stored in their own tag property
    /// </summary>
    /// <param name="flowDocument">The FlowDocument containing images/UI formats to be converted</param>
    /// <returns>Returns a FlowDocument with images in base 64 string in image tag property</returns>
    private FlowDocument TransformImagesTo64(FlowDocument flowDocument)
    {
        FlowDocument img_flowDocument;
        Paragraph img_paragraph;
        InlineUIContainer img_inline;
        System.Windows.Controls.Image newImage;
        Type inlineType;
        InlineUIContainer uic;
        System.Windows.Controls.Image replacementImage;

        //loop through replacing images in the flowdoc with the base64 versions
        foreach (Block b in flowDocument.Blocks)
        {
            //loop through inlines looking for images
            foreach (Inline i in ((Paragraph)b).Inlines)
            {
                inlineType = i.GetType();

                /*if (inlineType == typeof(Run))
                {
                    //The inline is TEXT!!! $$$$$ Kept in case needed $$$$$
                }
                else */if (inlineType == typeof(InlineUIContainer))
                {
                    //The inline has an object, likely an IMAGE!!!
                    uic = ((InlineUIContainer)i);

                    //if it is an image
                    if (uic.Child.GetType() == typeof(System.Windows.Controls.Image))
                    {
                        //grab the image
                        replacementImage = (System.Windows.Controls.Image)uic.Child;

                        //create a new image to be used to get base64
                        newImage = new System.Windows.Controls.Image();
                        //clone the image from the image in the flowdocument
                        newImage.Source = replacementImage.Source;

                        //create necessary objects to obtain a flowdocument in XamlFormat to get base 64 from
                        img_inline = new InlineUIContainer(newImage);
                        img_paragraph = new Paragraph(img_inline);
                        img_flowDocument = new FlowDocument(img_paragraph);

                        //Get the base 64 version of the XamlFormat binary
                        replacementImage.Tag = TransformImageTo64String(img_flowDocument);
                    }
                }
            }
        }
        return flowDocument;
    }

    /// <summary>
    /// Takes a FlowDocument containing a SINGLE Image, and converts to base 64 using XamlFormat
    /// </summary>
    /// <param name="flowDocument">The FlowDocument containing a SINGLE Image</param>
    /// <returns>Returns base 64 representation of image</returns>
    private string TransformImageTo64String(FlowDocument flowDocument)
    {
        TextRange documentTextRange = new TextRange(flowDocument.ContentStart, flowDocument.ContentEnd);
        using (MemoryStream ms = new MemoryStream())
        {
            documentTextRange.Save(ms, DataFormats.XamlPackage);
            ms.Position = 0;
            return Convert.ToBase64String(ms.ToArray());
        }
    }