1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
<?xml version="1.0"?>
<clause number="17.4.2.1" title="Using static readonly fields for constants">
<paragraph>A static readonly field is useful when a symbolic name for a constant value is desired, but when the type of the value is not permitted in a const declaration, or when the value cannot be computed at compile-time. <example>[Example: In the example <code_example><![CDATA[
public class Color
{
public static readonly Color Black = new Color(0, 0, 0);
public static readonly Color White = new Color(255, 255, 255);
public static readonly Color Red = new Color(255, 0, 0);
public static readonly Color Green = new Color(0, 255, 0);
public static readonly Color Blue = new Color(0, 0, 255);
private byte red, green, blue;
public Color(byte r, byte g, byte b) {
red = r;
green = g;
blue = b;
}
}
]]></code_example>the Black, White, Red, Green, and Blue members cannot be declared as const members because their values cannot be computed at compile-time. However, declaring them static readonly instead has much the same effect. end example]</example> </paragraph>
</clause>
|
