类型是DependencyProperty的属性是依赖属性 依赖属性不同于普通的.Net属性,类似于一个计算过程,根据依赖的值得到最终值. 为什么引入依赖属性: MSDN原文 One of the primary architectural philosophies used in building WPF was a preference for properties over methods or events. WPF的设计思想是侧重属性胜于方法和事件. 实例 依赖属性对资源引用的支持 设
转:http://lijiejava.iteye.com/blog/786535 一对多双向关联(类Item与类Bid): Item类: public class Item { private int id; private String name; private Set bids = new HashSet(); ••• } Bid类: public class Bid { private int id; private double amount; private Item item; •
报错如下: Expression # of SELECT list is not in GROUP BY clause and contains nonaggregated column ‘sss.month_id’ which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode=only_full_group_by 问题出现的原因: MySQL 5.7.5
安装了mysql5.7,用group by 查询时抛出如下异常: Expression # of SELECT list is not in GROUP BY clause and contains nonaggregated column 'userinfo.t_long.user_name' which is not functionally dependent on columns in GROUP BY clause; this is incompatible with sql_mode
IDEA下载依赖时提示 resolving dependencies of xxx, yyy ,卡住不动 使用Maven命令可以更清楚地分析问题,在IDEA命令行窗口执行mvn compile命令,提示: [ERROR] 'dependencies.dependency.systemPath' for jdk.tools:jdk.tools:jar must specify an absolute path but is ${JAVA_HOME}/lib/tools.jar @ line 160