from_argb() [4/4]

static xtd::drawing::color xtd::drawing::color::from_argb ( xtd::byte  red, xtd::byte  green, xtd::byte  blue  )

staticnoexcept

Creates a xtd::drawing::color structure from the specified 8-bit color values (red, green, and blue). The alpha value is implicitly 255 (fully opaque). Although this method allows a 32-bit value to be passed for each color component, the value of each component is limited to 8 bits.

Parameters

red	The red component. Valid values are 0 through 255.
green	The green component. Valid values are 0 through 255.
blue	The blue component. Valid values are 0 through 255.

Returns

xtd::drawing::color The xtd::drawing::color structure that this method creates.

Examples

The following code example is designed for use with Windows Forms, and it requires xtd::forms::paint_event_args e, which is a parameter of the xtd::forms::control::paint event handler. The code performs the following actions:

• Creates xtd::drawing::color structures from the three color component values (red, green, blue). Three xtd::drawing::color structures are created, one for each primary color.
• Iterates through a range of alpha values, changing the alpha value of a color.
• During each iteration, sets the color of a brush to the modified color and paints a rectangle to show the color.
• Repeats steps 2 and 3 for each primary color. The alpha value is never fully opaque and the rectangles overlap so you get color-combination effects.

  void from_argb2(paint_event_aArgs& e) {
    graphics g = e.graphics();
   
    // Opaque colors (alpha value defaults to 255 -- max value).
    color red = color::from_argb(255, 0, 0);
    color green = color::from_argb(0, 255, 0);
    color blue = color::from_argb(0, 0, 255);
   
    // Solid brush initialized to red.
    solid_brush my_brush(red);
    int alpha;
   
    // x coordinate of first red rectangle
    int x = 50;
   
    // y coordinate of first red rectangle
    int y = 50;
   
    // Fill rectangles with red, varying the alpha value from 25 to 250.
    for (alpha = 25; alpha <= 250; alpha += 25) {
      my_brush.color(color::from_argb(alpha, red));
      g.fill_rectangle(my_brush, x, y, 50, 100);
      g.fill_rectangle(my_brush, x, y + 250, 50, 50);
      x += 50;
    }
    // x coordinate of first green rectangle.
    x = 50;
   
    // y coordinate of first green rectangle.
    y += 50;
   
    // Fill rectangles with green, varying the alpha value from 25 to 250.
    for (alpha = 25; alpha <= 250; alpha += 25) {
      my_brush.color(color::from_argb(alpha, green));
      g.fill_rectangle(my_brush, x, y, 50, 150);
      x += 50;
    }
    // x coordinate of first blue rectangle.
    x = 50;
   
    // y coordinate of first blue rectangle.
    y += 100;
   
    // Fill rectangles with blue, varying the alpha value from 25 to 250.
    for (alpha = 25; alpha <= 250; alpha += 25) {
      my_brush.color(color::from_argb(alpha, blue));
      g.fill_rectangle(my_brush, x, y, 50, 150);
      x += 50;
    }
  }