20 lines
1.1 KiB
XML
20 lines
1.1 KiB
XML
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<?xml version="1.0"?>
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<clause number="17.4.2.1" title="Using static readonly fields for constants">
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<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[
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public class Color
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{
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public static readonly Color Black = new Color(0, 0, 0);
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public static readonly Color White = new Color(255, 255, 255);
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public static readonly Color Red = new Color(255, 0, 0);
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public static readonly Color Green = new Color(0, 255, 0);
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public static readonly Color Blue = new Color(0, 0, 255);
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private byte red, green, blue;
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public Color(byte r, byte g, byte b) {
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red = r;
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green = g;
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blue = b;
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}
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}
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]]></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>
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</clause>
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