We sometimes need to add a copyright watermark to a picture on our site, and the. NET Graphics class can be easily implemented.
Effect Diagram: (the top of the picture is the line that we added the copyright watermark)
Implementation code:
/**////<summary>
Generate a picture with a copyright watermark
</summary>
<param name= "iconimg" > File address to generate a watermark picture </param>
private void Makewatermark (string iconimg)
{
Define output bitmap
Bitmap bmp = New Bitmap (640, 480);
Defining drawing objects
Graphics g = graphics.fromimage (BMP);
Describe the drawing rectangle area
Rectangle newrect = new Rectangle (0, 0, 640, 480);
Set Background color
G.fillrectangle (New SolidBrush (Color.White), newrect);
Get a picture to generate a watermark
Bitmap Newbitmap = new Bitmap (iconimg);
G.drawimage (Newbitmap, 16, 16);
Defines the font for a watermark word
Font font = new Font (
"Arial",
12,
FontStyle.Bold
);
Define the format brush for the watermark Word
LinearGradientBrush brush = new LinearGradientBrush (
New Rectangle (0, 0, 71, 23),
Color.Red,
Color.Blue,
30f,
True
);
To mark a picture with a watermark
g.DrawString ("Copyright by Test." + System.DateTime.Now.ToShortDateString (), font, brush, 0, 0);
Save as a new output picture
System.IO.MemoryStream ms = new System.IO.MemoryStream ();
Bmp. Save (MS, Imageformat.jpeg);
Output picture
Response.clearcontent ();
Response.ContentType = "Image/jpeg";
Response.BinaryWrite (Ms. ToArray ());
}
