title: How to select an area on a PictureBox.Image with mouse in C#
body: <p>i just wanted to put a selection on my picturebox.image but this has just become worse than some little annoying situation. I thought on another picture box over the main picturebox but it seemed so lazy work to me. I need to know if there is a way to create a selection area (which is gonna be half transparent blue area) on a picturebox.image which im gonna draw with mouse and it shouldnt change the image im working on.</p>
  
  <p>sample:</p>
  
  <pre><code>    // Start Rectangle
      //
      private void pictureBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
      {
          // Determine the initial rectangle coordinates...
          RectStartPoint = e.Location;
          Invalidate();
      }
  
      // Draw Rectangle
      //
      private void pictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
      {
          if (e.Button != MouseButtons.Left)
              return;
          Point tempEndPoint = e.Location;
          Rect =
              new Rectangle(
                  Math.Min(RectStartPoint.X, tempEndPoint.X),
                  Math.Min(RectStartPoint.Y, tempEndPoint.Y),
                  Math.Abs(RectStartPoint.X - tempEndPoint.X),
                  Math.Abs(RectStartPoint.Y - tempEndPoint.Y));
          Invalidate(Rect);
      }
  
      // Draw Area
      //
      private void pictureBox1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
      {
          // Draw the rectangle...
          if (pictureBox1.Image != null)
          {
              Brush brush = new SolidBrush(Color.FromArgb(128, 72, 145, 220));
              e.Graphics.FillRectangle(brush, Rect);
          }
      }
  </code></pre>