Write text on an image in C#

To draw multiple strings, call graphics.DrawString multiple times. You can specify the location of the drawn string. This example we will draw two strings "Hello", "Word" ("Hello" in blue color upfront "Word" in red color):

string firstText = "Hello";
string secondText = "World";

PointF firstLocation = new PointF(10f, 10f);
PointF secondLocation = new PointF(10f, 50f);

string imageFilePath = @"path\picture.bmp"
Bitmap bitmap = (Bitmap)Image.FromFile(imageFilePath);//load the image file

using(Graphics graphics = Graphics.FromImage(bitmap))
{
    using (Font arialFont =  new Font("Arial", 10))
    {
        graphics.DrawString(firstText, arialFont, Brushes.Blue, firstLocation);
        graphics.DrawString(secondText, arialFont, Brushes.Red, secondLocation);
    }
}

bitmap.Save(imageFilePath);//save the image file

Edit: "I Add a load and save code".

You can open the bitmap file any time Image.FromFile, and draw a new text on it using the above code. and then save the image file bitmap.Save

Here's an example of a call to Graphics.DrawString, taken from here:

g.DrawString("My\nText", new Font("Tahoma", 40), Brushes.White, new PointF(0, 0));

It obviously relys on having a font called Tahoma installed.

The Brushes class has many built-in brushes.

See also, the MSDN page for Graphics.DrawString.

To save changes to the same file, I had to combine Jalal Said's answer and NSGaga's answer on this question. You need to create a new Bitmap object based on the old one, dispose old Bitmap object, then save using the new object:

string firstText = "Hello";
string secondText = "World";

PointF firstLocation = new PointF(10f, 10f);
PointF secondLocation = new PointF(10f, 50f);

string imageFilePath = @"path\picture.bmp";

Bitmap newBitmap;
using (var bitmap = (Bitmap)Image.FromFile(imageFilePath))//load the image file
{
    using(Graphics graphics = Graphics.FromImage(bitmap))
    {
        using (Font arialFont =  new Font("Arial", 10))
        {
            graphics.DrawString(firstText, arialFont, Brushes.Blue, firstLocation);
            graphics.DrawString(secondText, arialFont, Brushes.Red, secondLocation);
        }
    }
    newBitmap = new Bitmap(bitmap);
}

newBitmap.Save(imageFilePath);//save the image file
newBitmap.Dispose();