小编Bit*_*map的帖子

我刚刚遇到过这个关键字C++ Mixin-Style,有谁知道这是什么？

在这篇文章中,已被回答为一种设计模式.它是否与本文档中描述的设计模式相同？

我有我在所有文件中包含的配置文件,我有不同的枚举,但在每个枚举中有相同的元素名称,例如:config.h

enum GameObjectType
{
     NINJA_PLAYER

};
enum GameObjectTypeLocation
{
    NONE,
    MASSAGE_ALL,  //this is for ComponentMadiator
    NINJA_PLAYER


};

但是当我尝试使用适当的枚举名称调用枚举来编译项目时

m_pNinjaPlayer = (NinjaPlayer*)GameFactory::Instance().getGameObj(GameObjectType::NINJA_PLAYER);
    ComponentMadiator::Instance().Register(GameObjectTypeLocation::NINJA_PLAYER,m_pNinjaPlayer);

我收到编译错误:

error C2365: 'NINJA_PLAYER' : redefinition; previous definition was 'enumerator' (..\Classes\GameFactory.cpp)
2>          d:\dev\cpp\2d\cocos2d-x-3.0\cocos2d-x-3.0\projects\lettersfun\classes\config.h(22) : see declaration of 'NINJA_PLAYER'

如何在config.h中保留几个具有不同名称但具有相同元素名称的枚举？

这两种using关键字用法有什么区别:

using boost::shared_ptr;

和

using namespace boost;

使用以下示例代码:

String column_names[]= {"Serial Number","Medicine Name","Dose","Frequency"};
table_model=new DefaultTableModel(column_names,3);
table=new JTable(table_model);

我们希望使用上面的代码在column_names中设置包含列名称的标题,但它不起作用.虽然表已创建,但页眉不可见.

我有一张staff带office柱子的桌子.目前,该office列不接受NULL值.持久存在此表上的应用程序有一个错误,这意味着,当工作人员尚未分配办公室时,它会尝试在表上插入NULL值.

我被要求使用触发器拦截插入到Staff表上并检查office值是否为NULL并将其替换为值N/A.

以下是我到目前为止的尝试,但确实error试图实施.有关如何解决此问题的任何想法.

CREATE TRIGGER staffOfficeNullReplacerTrigger BEFORE INSERT ON Staff
  FOR EACH ROW BEGIN
    IF (NEW.office IS NULL)
     INSERT INTO Staff SET office="N/A";
    END IF
  END;

错误:

MySQL数据库错误:您的SQL语法有错误; 检查与您的MySQL服务器版本对应的手册,以便在'INSERT INTO Staff SET office ="N/A"附近使用正确的语法; 结束'

我在这张图片上有3个div:

div1有固定宽度但可变高度,所以我想要的是,如果div1高度大于div2高度,则div3保持在div2下方和div1右侧,如下所示:

有关如何做到这一点的任何想法？目前,我已经创建了一个容器:

<div class="colcontainer">
    <div class="col-left">
    {% block news %}{% endblock %}
    </div>  
    <div id="main_content">
        <div class="col-right">
            {% block rightcol %}{% endblock %}
        </div> 
        <div id="content">
            <div class="contentwrap">
                <div class="itemwrap">
                {% block content %}{% endblock %}
            </div>
        </div>
    </div>

    <div class="content-bottom"><div class="content-bottom-left"></div></div>
    </div>
</div>

我的CSS是这样的:

.col-left {
    float:left;
    padding:0;
    margin:0;
    width: 300px;
    min-height:198px;
}

.col-right {
    text-align:left;
    padding:0;
    margin:0 0 0 200px;
}

#content {
    background: none repeat scroll 0 0 #FFFFFF;
    float: left;
    margin-top: 10px;
    padding: 10px;
    width: …

我有旧的底片,我扫描到我的电脑上.我想写一个小程序将负图像转换为正状态.

我知道有几个图像编辑器应用程序,我可以使用它来实现这种转换,但我正在研究如何通过一个小应用程序操纵像素自己转换它们.

有人能给我一个良好的开端吗？如果可能的话,示例代码也将非常受欢迎.

我试图检查是否#include <file.h>已经使用C++宏声明了.

例

在file.h我做:

#ifndef FILE.H
#define FILE.H
class A
{
  //do routines 
};
#endif

在第二个文件中,second.h我想检查是否file.h已经包含.

典型的伪代码:

#ifndef "file.h"
#include "file.h"
#endif

#ifndef SECOND.H
#define SECOND.H
class second
{
  //do routine
};
#endif

我尝试了一些#ifndef指令,但没有快乐.有谁知道如何实现这一目标？

如何将我通过javamail编写的消息存储到MySQL表中？我已经配置james服务器配置文件连接到MySQL服务器(数据源元素名称为maildb),我将<inboxRepository>James服务器配置文件中的元素更改为

<inboxRepository>
  <repository destinationURL="db://maildb/spammer/"
    type="MAIL"/>      
</inboxRepository>

但是我仍然无法从MySql中的邮件数据库中的垃圾邮件发送者表的收件箱列中读取邮件.

这是我的javamail类:

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Properties;
import javax.mail.*;
import javax.mail.internet.*;

public class mail{

  public static void main(String[] argts){
    String to = "red@localhost";
    String from = "blue@localhost";
    String subject = "jdk";
    String body = "Down to wind";

    if ((from != null) && (to != null) 
      && (subject != null)  && (body != null)) 
    // we have mail to send
    {
      try {
        Properties props = new Properties();

        props.put("mail.host", "127.0.0.1 ");
        props.put("mail.smtp.auth","true"); …

我刚刚遇到了hibernate配置的问题.

我得到的Stacktrace是:

Servlet.service() for servlet jsp threw exception
org.hibernate.hql.ast.QuerySyntaxException: TESTPROJECTBEAN is not mapped [FROM TESTPROJECTBEAN]
at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:181)
at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:94)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:316)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3228)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3112)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:720)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:571)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:288)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:231)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:254)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:101)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:94)
at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:156)
at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:135)
at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1651)
at projectConfiguration.ITBProjectDetails.loadProjectList(ITBProjectDetails.java:21)
at org.apache.jsp.WEB_002dINF.jsp.home.projectConfigurationHome_jsp._jspService(projectConfigurationHome_jsp.java:103)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:127)
at com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:56)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at …