C # Two different scenarios and solutions for adding a watermark to a picture _c# tutorial

Scene One

That is, we often use, is generally the picture of the 4 corners, based on horizontal ordinate to add.

The effect is as follows:

Add Watermark Method

static void Addwatermarktext (Graphics picture,int fontsize, String _watermarktext, string _watermarkposition, int _width
   , int _height) {int[] sizes = new int[] {32, 14, 12, 10, 8, 6, 4};
   Font crfont = null;
 
   SizeF crsize = new SizeF ();
   Crfont = new Font ("Microsoft Ya Hei", FontSize, FontStyle.Bold); Crsize = picture.
 
   MeasureString (_watermarktext, Crfont);
   float xpos = 0;
   float ypos = 0;
 
   Color color =color.firebrick;
     Switch (_watermarkposition) {case "Wm_top_left": Xpos = ((float) _width * (float).) + (CRSIZE.WIDTH/2);
     Ypos = (float) _height * (float). 01;
    Break
     Case "Wm_top_right": Xpos = ((float) _width * (float)-(CRSIZE.WIDTH/2);
     Ypos = (float) _height * (float). 01;
    Break
     Case "Wm_bottom_right": Xpos = ((float) _width * (float)-(CRSIZE.WIDTH/2);
     Ypos = ((float) _height * (float)-crsize.height;
    Break Case "Wm_bottom_left": Xpos = ((float) _width * (float) + (crsize.wiDTH/2);
     Ypos = ((float) _height * (float)-crsize.height;
     
   Break
   } StringFormat Strformat = new StringFormat ();
   Strformat.alignment = Stringalignment.center; SolidBrush semiTransBrush2 = new SolidBrush (Color.FromArgb (153, 0, 0, 0))//Add shadow picture.
 
   DrawString (_watermarktext, Crfont, SEMITRANSBRUSH2, xpos + 1, ypos + 1, strformat); SolidBrush Semitransbrush = new SolidBrush (color); Add a watermark to the picture.
 
   DrawString (_watermarktext, Crfont, Semitransbrush, xpos, ypos, Strformat);
   Semitransbrush2.dispose ();
  Semitransbrush.dispose (); }

Scene Two

The text is always centered within the picture, based on a fixed position. In the beginning, I based on the first scenario to compute the coordinates based on the length of the watermark characters, and later found that the method was always unreliable. Now it's time to draw a rectangle in the picture's fixed area (the Watermark area), and then add the watermark characters to the rectangle, and use the brush to keep the text centered.

The effect chart is as follows

How to add a watermark

static void Addwatermarktext (Graphics picture,string type, int fontsize, string _watermarktext)
  {
   //1, first draw rectangle
   RectangleF DrawRect;
   Color color;
   if (type = = "Top")
   {
     drawrect = new RectangleF (135, 450,);
     color = Color.FromArgb (255, 255, 255);
   }
   else
   {
     drawrect = new RectangleF (194, 245,);
     color = Color.FromArgb (244, N.);
    
   2, based on the rectangular watermark text
   Font crfont = null;
 
   StringFormat Strformat = new StringFormat ();
   Strformat.alignment = Stringalignment.center;
 
   Crfont = new Font ("Microsoft Ya Hei", FontSize, fontstyle.bold);
   SolidBrush Semitransbrush = new SolidBrush (color); Add a watermark to the picture
   . DrawString (_watermarktext, Crfont, Semitransbrush, DrawRect, Strformat);
 
   Semitransbrush.dispose ();
  }

Summarize

Compared to the first method, the second method is more intuitive, more concise, you need to add a watermark on the picture to calculate the fixed coordinates and then draw a rectangle, and then the watermark characters in the rectangle, so no matter how the watermark changes can be in the picture fixed position Center. The above is the entire content of this article, I hope to be able to study or work to bring certain help.