How To Set Background None Color ASP.NET C#

Question

Generate an Image From Text

public Image DrawText(String text, Font font, Color textColor, Color backColor)
{
    //first, create a dummy bitmap just to get a graphics object
    Image img = new Bitmap(1, 1);
    Graphics drawing = Graphics.FromImage(img);

    //measure the string to see how big the image needs to be
    SizeF textSize = drawing.MeasureString(text, font);

    //free up the dummy image and old graphics object
    img.Dispose();
    drawing.Dispose();

    //create a new image of the right size
    img = new Bitmap((int)textSize.Width, (int)textSize.Height);

    drawing = Graphics.FromImage(img);

    //paint the background
    drawing.Clear(backColor);

    //create a brush for the text
    Brush textBrush = new SolidBrush(textColor);

    drawing.DrawString(text, font, textBrush, 0, 0);

    drawing.Save();

    textBrush.Dispose();
    drawing.Dispose();

    return img;
}

And Callback

Font font = new Font("Arial", 20, FontStyle.Bold);
Color color = Color.FromArgb(255, 0, 0); //Red
Color background = Color.Transparent;    //None Color
Image img = DrawText("Hoàng Long", font, color, background);
img.Save(context.Response.OutputStream, ImageFormat.Jpeg);

Tried:How to generate an image from text on fly at runtime

Please help me

First of all, a Jpeg cannot have a transparent background. You need gif or png for that. — VDWWD, Oct 26 '18 at 12:31

Jawand Singh · Accepted Answer · 2018-10-26T12:37:46.113

Disclaimer: this code will create a white background. Not an Transparent. To make it Transparent you need to change this var image = DrawTextImage(TextForImage, font, Color.Black, Color.Transparent);

public class TextToImage
{
    // main method you need to call.
    public byte[] GetImageFromText(string TextForImage)
    {
        FontFamily fontFamily = new FontFamily("Arial");
        Font font = new Font(fontFamily, 40.0f);
        var image = DrawTextImage(TextForImage, font, Color.Black, Color.Transparent);
        var imgData = ImageToByteArray(image);
        return imgData;
    }
    // convert image to byte array
    private byte[] ImageToByteArray(System.Drawing.Image imageIn)
    {
        MemoryStream ms = new MemoryStream();
        imageIn.Save(ms, System.Drawing.Imaging.ImageFormat.Jpeg);
        return ms.ToArray();
    }

    private Image DrawTextImage(String text, Font font, Color textColor, Color backColor)
    {
        return DrawTextImage(text, font, textColor, backColor, new Size(500, 500));
    }
    // create image
    private Image DrawTextImage(String text, Font font, Color textColor, Color backColor, Size minSize)
    {
        //first, create a dummy bitmap just to get a graphics object
        SizeF textSize;
        using (Image img = new Bitmap(1, 1))
        {
            using (Graphics drawing = Graphics.FromImage(img))
            {
                //measure the string to see how big the image needs to be
                textSize = drawing.MeasureString(text, font);
                if (!minSize.IsEmpty)
                {
                    textSize.Width = textSize.Width > minSize.Width ? textSize.Width : minSize.Width;
                    textSize.Height = textSize.Height > minSize.Height ? textSize.Height : minSize.Height;
                }
            }
        }

        //create a new image of the right size
        //Image retImg = new Bitmap((int)textSize.Width, (int)textSize.Height);
        Image retImg = new Bitmap(500, 500);
        using (var drawing = Graphics.FromImage(retImg))
        {
            //paint the background
            drawing.Clear(backColor);

            //create a brush for the text
            using (Brush textBrush = new SolidBrush(textColor))
            {
                drawing.TextRenderingHint = TextRenderingHint.AntiAlias;
                RectangleF rectF1 = new RectangleF(10, 10, 490, 490);
                drawing.DrawString(text, font, textBrush, rectF1);
                drawing.Save();
            }
        }
        return retImg;
    }

}

I think above code is self explanatory. you just create an instance of this helper class and pass text param.

TextToImage textToImage = new TextToImage();
byte[] byteArr = textToImage.GetImageFromText("some text to create image out of it");

Hope this helps. :)

How To Set Background None Color ASP.NET C#

Generate an Image From Text

And Callback

Please help me

1 Answers1