How can I insert an image into a RichTextBox?

Question

Most of the examples I see say to put it on the clipboard and use paste, but that doesn't seem to be very good because it overwrites the clipboard.

I did see one method that manually put the image into the RTF using a pinvoke to convert the image to a wmf. Is this the best way? Is there any more straightforward thing I can do?

Additional

You can paste (Ctrl+V) an image into a RichTextBox - Funny thing though; When I save the RichTextBox RTF property to a file while the image is already pasted into the RichTextBox, it seems to also save the image in the RTF as well. (I re-loaded the RTF using RichTextBox.Load(), and it loaded the image from the saved RTF) – Duvetyn

Answer 1

The most straightforward way would be to modify the RTF code to insert the picture yourself.

In RTF, a picture is defined like this:

'{' \pict (brdr? & shading? & picttype & pictsize & metafileinfo?) data '}' A question mark indicates the control word is optional. "data" is simply the content of the file in hex format. If you want to use binary, use the \bin control word.

For instance:

{\pict\pngblip\picw10449\pich3280\picwgoal5924\pichgoal1860 hex data}
{\pict\pngblip\picw10449\pich3280\picwgoal5924\pichgoal1860\bin binary data}

\pict = starts a picture group, \pngblip = png picture \picwX = width of the picture (X is the pixel value) \pichX = height of the picture \picwgoalX = desired width of the picture in twips

So, to insert a picture, you just need to open your picture, convert the data to hex, load these data into a string and add the RTF codes around it to define a RTF picture. Now, you have a self contained string with picture data which you can insert in the RTF code of a document. Don't forget the closing "}"

Next, you get the RTF code from your RichTextBox (rtbBox.Rtf), insert the picture at the proper location, and set the code of rtbBox.Rtf

One issue you may run into is that .NET RTB does not have a very good support of the RTF standard.

I have just made a small application* which allows you to quickly test some RTF code inside a RTB and see how it handles it. You can download it here: RTB tester (http://your-translations.com/toys).

You can paste some RTF content (from Word, for instance) into the left RTF box and click on the "Show RTF codes" to display the RTF codes in the right RTF box, or you can paste RTF code in the right RTB and click on "Apply RTF codes" to see the results on the left hand side.

You can of course edit the codes as you like, which makes it quite convenient for testing whether or not the RichTextBox supports the commands you need, or learn how to use the RTF control words.

You can download a full specification for RTF online.

---

NB It's just a little thing I slapped together in 5 minutes, so I didn't implement file open or save, drag and drop, or other civilized stuff.

Combes

I could not get RTB to show pngs, but at least it does show wmf. – Chock

1 "twip" = 1/20 of a point. 1 point ~ 1.333 pixels (this depends on screen resolution; most monitors today run 96 pixels per inch in their native resolution so this holds) – Monologue

As far as I can determine, RichTextBox (and hence RTBTester) does not accept \pngblip. It only accepts \wmetafile[8]. See this reference for a more complete explanation: codeproject.com/Articles/4544/…. I do know that if I save the RTF from a RichTextBox, then it can have \pngblip. However, copying the {\pngblip....} construct to RTBTester does not show the image. – Danutadanya

@KennethEvans Actually, the article says that [...]A user can insert bitmaps, JPEGs, GIFs, Icons, PNGs, and TIFFs[...]. I've tested pasting a PNG image to the RichTextBox and checking the RTF property, and it works fine. – Alfredalfreda

@Sylverdrag : the your-translations.com/toys link is broken ... – Everlasting

Answer 2

I use the following code to first get the data from clipboard, save it in memory, set the image in clipboard, paste it in Rich Text Box and finally restore the data in Clipboard.

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    OpenFileDialog1.Filter = "All files |*.*"
    OpenFileDialog1.Multiselect = True
    Dim orgdata = Clipboard.GetDataObject

    If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
        For Each fname As String In OpenFileDialog1.FileNames
            Dim img As Image = Image.FromFile(fname)
            Clipboard.SetImage(img)
            RichTextBox1.Paste()

        Next
    End If
    Clipboard.SetDataObject(orgdata)
End Sub

The OpenFileDailog1, RichTextBox1 and Button1 are Open File Dialog, Rich Text Box and button controls respectively.

Branca

To be honest, I was skeptical of this solution. I mean, if you already have an image on the clipboard (in my case), then taking it off the clipboard, and putting it right back on shouldn't do anything. But SOMEHOW this exact trick worked like a dream. THANK YOU! – Isobar

What happen if Richtextbox Read only Property is set to be true? This clipboard method will be fail. – Fluorite

@Jerry: You've misunderstood. The data on the clipboard at the beginning is not part of the insert-image-into-richtext process. Bibek's answer features "put things back the way you found them" logic. – Hunker

I don't think setting the Clipboard data back to it's previous state actually works. Rather it's left empty. – Ornament

Answer 3

private void toolStripButton1_Click(object sender, EventArgs e)
    {
        FileDialog fDialog = new OpenFileDialog();
        fDialog.CheckFileExists = true;
        fDialog.CheckPathExists = true;
        fDialog.RestoreDirectory = true;
        fDialog.Title = "Choose file to import";
        if (fDialog.ShowDialog() == DialogResult.OK)
        {
            string lstrFile = fDialog.FileName;
            Bitmap myBitmap = new Bitmap(lstrFile);
            // Copy the bitmap to the clipboard.
            Clipboard.SetDataObject(myBitmap);
            DataFormats.Format format = DataFormats.GetFormat(DataFormats.Bitmap);
            // After verifying that the data can be pasted, paste
            if(top==true && this.rtTop.CanPaste(format))
            {
                rtTop.Paste(format);
            }
            if (btmLeft == true && this.rtBottomLeft.CanPaste(format))
            {
                rtBottomLeft.Paste(format);
            }
            if (btmCenter == true && this.rtBottomCenter.CanPaste(format))
            {
                rtBottomCenter.Paste(format);
            }
            if (btmRight == true && this.rtBottomRight.CanPaste(format))
            {
                rtBottomRight.Paste(format);
            }
        }
    }

Sparky

== true is literally the most useless code I've ever seen. – Chancellorsville

Answer 4

Here is what I do to hack the rich text control:

Insert the required image in wordpad or MS-WORD. Save the file as 'rtf'. Open the rtf file in notepad to see the raw rtf code. Copy the required tags & stuff to the 'rtf' property of your Rich Text Box (append to existing text).

There is some trial and error involved but works.

With C#, I use place holder StringBuilder objects with the necessary rtf code. Then I just append the image path.

This is a workaround for not having to learn the RTF syntax.

Comeaux

I am searching for "How to insert an image in Richtextbox" since morning, But all is van. After Reading this answer I have don it in less then 180 Seconds. +1 for you. – Fluorite

Answer 5

My own version that I posted in a new thread, apparently I should have searched and posted it here. Anyway, using the clipboard again, very easy.

private void button1_Click(object sender, EventArgs e)
    {
        openFileDialog1.Filter = "Images |*.bmp;*.jpg;*.png;*.gif;*.ico";
        openFileDialog1.Multiselect = false;
        openFileDialog1.FileName = "";
        DialogResult result = openFileDialog1.ShowDialog();
        if (result == DialogResult.OK)
        {
            Image img = Image.FromFile(openFileDialog1.FileName);
            Clipboard.SetImage(img);
            richTextBox1.Paste();
            richTextBox1.Focus();
        }
        else
        {
            richTextBox1.Focus();
        }

    }
}

Pedaiah

Answer 6

If you were in C++, the way to do it is thru OLE. More specifically, if you search Google for ImageDataObject it will show C++ code how to insert a HBITMAP into the RTF Control. One link is here.

Now, how this translates into .Net code, I don't know. I currently don't have the time to work thru the details.

Ardra

Answer 7

I was also looking for something for this same task and found this ->

http://sourceforge.net/projects/netrtfwriter/

You can generate any type of RTF text that you would want and then use it however you wish. Very well structured example which will auto sense the image type being used (jpg/jpeg/png etc) and worked for the image files I have been using. If you are in a hurry then this is a great RTF generator!

Mishnah

This should have been elected answer :) – Duvetyn

Answer 8

All I did was make a small pictureBox control in c# and made sure it was hidden behind another object big enough to hide it. Then I made a button to insert a picture, and it loaded the pictureBox with the image then it puts it in the richTextBox then it clears the pictureBox control.

Here is the code.

 private void InsertPicture_Click(object sender, EventArgs e)
    {

                    {
            if (openFileDialog4.ShowDialog() == DialogResult.OK)
            {
                // Show the Open File dialog. If the user clicks OK, load the 
                // picture that the user chose.   
                pictureBox2.Load(openFileDialog4.FileName);
                Clipboard.SetImage(pictureBox2.Image);
                pictureBox2.Image = null;
                this.richTextBox1.Paste();

            }
    }
}

Cardiac

Answer 9

After inserting the code to do it with the clipboard, type in Clipboard.Clear();. It works well and it doesn't clear everything, only the item last added to the clipboard.

Full Code:

private void addPictureToRTB()
{
    using (OpenFileDialog ofd = new OpenFileDialog() { Filter = "Pictures|*.png" })
    {
         if (ofd.ShowDialog() == DialogResult.OK)
         {
               ClipBoard.SetImage(Image.FromFile(ofd.FileName));
               richTextBox.Paste();
               Clipboard.Clear();
         }
    }
}

Then reference this function where you need to.

Clabber

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center. – Rumilly

Answer 10

Several hours surfing for solution to insert image without loosing quality and fixed the gray background with transparent image/png

                // assuming the image is in your Resources
                var img = Resources.ImageWithTransparentBckgrnd;
                var g = Graphics.FromImage(img);
                using (var ms = new MemoryStream())
                {
                    img.Save(ms, ImageFormat.Png);
                    IntPtr ipHdc = g.GetHdc();
                    Metafile mf = new Metafile(ms, ipHdc);
                    g = Graphics.FromImage(mf);
                    g.FillEllipse(Brushes.White, 0, 0, 16, 16); // size you want to fill in
                    g.Dispose();
                    mf.Save(ms, ImageFormat.Png);
                    IDataObject dataObject = new DataObject();
                    dataObject.SetData("PNG", false, ms);
                    Clipboard.SetDataObject(dataObject, false);
                    richTextBox1.Paste();
                    SendKeys.Send("{RIGHT}");
                    richTextBox1.Focus();
                }

Salyers