How to convert HTML to RTF and vice versa in Windows 10 UWP?

Question

I am working on RichEditBox Control in Windows 10 UWP to allow a user with some formatting options.I am getting a HTML from the server and I want to convert that into RTF to display it in RichEditBox. Similarly, I want to convert it again to HTML when the user has completed editing. I did a search but I got samples but they are not helping. One of them that I found is working for RichTextBlock, not RichEditBox

HTML to RTF

I also tried below URL(RTF to HTML) but it doesn't give proper output

RTF to HTML

Please, someone, suggest how to achieve my requirement with RichEditBox as it is only control that allows formatting options as Bold,Italic,Bullet points etc.

If you have money for a 3rd party library it would be trivial. Search for document convertors. — Crowcoder, Apr 29 '16 at 10:43
I've only used [text control](www.textcontrol.com/html5) but that is much more than a converter. Look at Aspose, gnostice — Crowcoder, Apr 29 '16 at 10:50
@Kinjan I am also in same situation, have you got any converters? or any solutions for this? — Noorul, Sep 23 '16 at 09:55
@Noorul No I have to keep this feature on hold as I didn't found any converter. If you find something let me know. — Kinjan Bhavsar, Sep 26 '16 at 09:11
@Noorul Microsoft should provide some easy conversion for this in coming SDK update, what you say? — Kinjan Bhavsar, Sep 26 '16 at 09:31
@kinjan yes of course, there must me some inbuilt method with in the RichEditBox itself, to convert that RTF to possible most used formats like HTML. — Noorul, Sep 26 '16 at 09:46
@Noorul, I checked it in past and there is no inbuilt method function available for conversion. — Kinjan Bhavsar, Sep 26 '16 at 09:49
sorry, What mean to say is, its really needed to have a inbuilt method, but none is available currently . Even i also tried a lot.Now I got a converter in WPF, trying to use it in UWP. Lets c..... — Noorul, Sep 26 '16 at 10:13
@Noorul If it works for you, please post it as answer, I will mark it as accepted answer. — Kinjan Bhavsar, Sep 26 '16 at 10:16
ya, sure. But am really struggling a lot to find the missing library's . Lot of changes happened between WPF and UWP. Let me give a try , hope for good. — Noorul, Sep 26 '16 at 10:24
Hi Kinjan, I have got a convertion method which i modified a little, it is converting for text formats . But i didn't analysed the scenario with Image. Anyway i will post the answer. — Noorul, Sep 29 '16 at 09:43

Noorul · Accepted Answer · 2016-10-13T10:08:41.657

I found the base concept to convert in this link , and I created the following method to convert rtf to html . it converts the text format options correctly.

Here is the method which converts rtf to html , u can edit as per ur need

 public static string ConvertToHtml(RichEditBox richEditBox)
    {
        string text, strColour, strFntName, strHTML;
        richEditBox.Document.GetText(TextGetOptions.None, out text);
        ITextRange txtRange = richEditBox.Document.GetRange(0, text.Length);
        strHTML = "<html>";

        int lngOriginalStart = txtRange.StartPosition;
        int lngOriginalLength = txtRange.EndPosition;
        float shtSize = 11;

        // txtRange.SetRange(txtRange.StartPosition, txtRange.EndPosition);

        bool bOpened = false, liOpened = false, numbLiOpened = false, iOpened = false, uOpened = false, bulletOpened = false, numberingOpened = false;

        for (int i = 0; i < text.Length; i++)
        {
            txtRange.SetRange(i, i + 1);

            if (i == 0)
            {
                strColour = txtRange.CharacterFormat.ForegroundColor.ToString();
                shtSize = txtRange.CharacterFormat.Size;
                strFntName = txtRange.CharacterFormat.Name;
                strHTML += "<span style=\"font-family:" + strFntName + "; font-size: " + shtSize + "pt; color: #" + strColour.Substring(3) + "\">";
            }


            if (txtRange.CharacterFormat.Size != shtSize)
            {
                shtSize = txtRange.CharacterFormat.Size;
                strHTML += "</span><span style=\"font-family: " + txtRange.CharacterFormat.Name + "; font-size: " + txtRange.CharacterFormat.Size + "pt; color: #" + txtRange.CharacterFormat.ForegroundColor.ToString().Substring(3) + "\">";
            }

            if (txtRange.Character == Convert.ToChar(13))
            {
                strHTML += "<br/>";
            }

            #region bullet
            if (txtRange.ParagraphFormat.ListType == MarkerType.Bullet)
            {
                if (!bulletOpened)
                {
                    strHTML += "<ul>";
                    bulletOpened = true;
                }

                if (!liOpened)
                {
                    strHTML += "<li>";
                    liOpened = true;
                }

                if (txtRange.Character == Convert.ToChar(13))
                {
                    strHTML += "</li>";
                    liOpened = false;
                }
            }
            else
            {
                if (bulletOpened)
                {
                    strHTML += "</ul>";
                    bulletOpened = false;
                }
            }

            #endregion

            #region numbering
            if (txtRange.ParagraphFormat.ListType == MarkerType.LowercaseRoman)
            {
                if (!numberingOpened)
                {
                    strHTML += "<ol type=\"i\">";
                    numberingOpened = true;
                }

                if (!numbLiOpened)
                {
                    strHTML += "<li>";
                    numbLiOpened = true;
                }

                if (txtRange.Character == Convert.ToChar(13))
                {
                    strHTML += "</li>";
                    numbLiOpened = false;
                }
            }
            else
            {
                if (numberingOpened)
                {
                    strHTML += "</ol>";
                    numberingOpened = false;
                }
            }

            #endregion

            #region bold
            if (txtRange.CharacterFormat.Bold == FormatEffect.On)
            {
                if (!bOpened)
                {
                    strHTML += "<b>";
                    bOpened = true;
                }
            }
            else
            {
                if (bOpened)
                {
                    strHTML += "</b>";
                    bOpened = false;
                }
            }
            #endregion

            #region italic
            if (txtRange.CharacterFormat.Italic == FormatEffect.On)
            {
                if (!iOpened)
                {
                    strHTML += "<i>";
                    iOpened = true;
                }
            }
            else
            {
                if (iOpened)
                {
                    strHTML += "</i>";
                    iOpened = false;
                }
            }
            #endregion

            #region underline
            if (txtRange.CharacterFormat.Underline == UnderlineType.Single)
            {
                if (!uOpened)
                {
                    strHTML += "<u>";
                    uOpened = true;
                }
            }
            else
            {
                if (uOpened)
                {
                    strHTML += "</u>";
                    uOpened = false;
                }
            }
            #endregion

            strHTML += txtRange.Character;
        }


        strHTML += "</span></html>";

        return strHTML;
    }

And I am yet to start the reverse conversion for html to rtf, once i done with that, i will post that answer too.

Hope this helps.

Thanks,

Noorul.

No but will try and if it works will mark answer as accepted. Also, how to handle bullet points and nymbers list? Did you tried that? — Kinjan Bhavsar, Oct 03 '16 at 05:11
Yes , I forget to inform that. Even i got stuck in there, There is no conversion for bullet points, currently i am going forward with this simple conversion, since I need to complete it soon. Later i will add the conversion for bullet points too, and will edit the answer. — Noorul, Oct 03 '16 at 06:46
Hi Kinjan, I updated the answer for bullet and numbering too. — Noorul, Oct 13 '16 at 10:10
Thanks a lot. Did you checked my other question, if you can help me with that? — Kinjan Bhavsar, Oct 13 '16 at 10:11
Yes I checked, am not that much familiar with those concepts.I regret that I can't help you in that.:( — Noorul, Oct 13 '16 at 10:13
This works fine. But I want to remove `` which is added during conversion. Is it possible? — Kinjan Bhavsar, Oct 13 '16 at 11:08
yes , u can. it gives the style options. if you remove that u need to add some alternate for that, or go without style options. — Noorul, Oct 14 '16 at 09:09
@Noorul To help others, you may want to add a line in your original post that states that your solution covers the features of converting of the bullets and numbering, as well. I had first ignored your solution after reading a comment from a user that it does not cover bullets and numbering. But then I had to go through all the comments of this post to later discover that you indeed cover those two features as well. — nam, Mar 02 '19 at 17:24

How to convert HTML to RTF and vice versa in Windows 10 UWP?

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