ios app 阿拉伯语 RTL 的NSWritingDirectionAttributeName

1. //NSWritingDirectionAttributeName 设置文字书写方向，取值为以下组合

2. // iOS9.0以前

3. //@[@(NSWritingDirectionLeftToRight | NSTextWritingDirectionEmbedding)]

4. //@[@(NSWritingDirectionLeftToRight | NSTextWritingDirectionOverride)]

5. //@[@(NSWritingDirectionRightToLeft | NSTextWritingDirectionEmbedding)]

6. //@[@(NSWritingDirectionRightToLeft | NSTextWritingDirectionOverride)]

7. // iOS9.0以后

8. //@[@(NSWritingDirectionLeftToRight | NSWritingDirectionEmbedding)]

9. //@[@(NSWritingDirectionLeftToRight | NSWritingDirectionOverride)]

10. //@[@(NSWritingDirectionRightToLeft | NSWritingDirectionEmbedding)]

11. //@[@(NSWritingDirectionRightToLeft | NSWritingDirectionOverride)]

12. // NSWritingDirectionOverride 和 NSWritingDirectionEmbedding 是指定Unicode双向定义的格式控制算法

  1， @[@(NSWritingDirectionRightToLeft | NSWritingDirectionOverride)] 字符串右到左书写模式 ，如果是字符串是：“国家经济问题相关” 会显示成 “关相题问济经家国”，其他语言也是如此

 2，@[@(NSWritingDirectionRightToLeft | NSWritingDirectionEmbedding)]  字符串右到左书写模式 ，如果是字符串是：“国家经济问题相关” 会显示成 “国家经济问题相关”