Java - 移动int枚举

Question

在C中,我有时使用诸如的结构

enum {
   UIViewAutoresizingNone                 = 0,
   UIViewAutoresizingFlexibleLeftMargin   = 1 << 0,
   UIViewAutoresizingFlexibleWidth        = 1 << 1,
   UIViewAutoresizingFlexibleRightMargin  = 1 << 2,
   UIViewAutoresizingFlexibleTopMargin    = 1 << 3,
   UIViewAutoresizingFlexibleHeight       = 1 << 4,
   UIViewAutoresizingFlexibleBottomMargin = 1 << 5
};
typedef NSUInteger UIViewAutoresizing;

有没有Java等价物？

Answer 1

使用EnumSet.

摘自上面的Link作为示例:

package resolver;

import java.util.EnumSet;

public class EnumPatternExample {

    public enum Style {
        BOLD, ITALIC, UNDERLINE, STRIKETHROUGH
    }

    public static void main(String[] args) {
        final EnumSet<Style> styles = EnumSet.noneOf(Style.class);
        styles.addAll(EnumSet.range(Style.BOLD, Style.STRIKETHROUGH)); // enable all constants
        styles.removeAll(EnumSet.of(Style.UNDERLINE, Style.STRIKETHROUGH)); // disable a couple
        assert EnumSet.of(Style.BOLD, Style.ITALIC).equals(styles); // check set contents are correct
        System.out.println(styles);
    }

}

Answer 2

你不再需要在java中使用枚举的二进制逻辑了.你只需要enum自己和EnumSet.

例如:

enum Color {
   Red, Green, Blue, Orange, White, Black
}

...

EnumSet<Color> mainColors = EnumSet.of(Color.Red, Color.Green, Color.Blue);
Color color = getSomeColor();
if (mainColors.contains(color)) {
   //mainColors is like Red | Green | Blue, 
   //and contains() is like color & mainColors
   System.out.println("Your color is either red or blue or green"); 
}