在.net下打造mongoDb基于官方驱动最新版本
还是一如既往先把结构图放出来,上上个版本添加了redis的缓存,但是不满足我的需求,因为公司有项目要求是分布式所以呢,这里我就增加了mongoDb进行缓存分布式,好了先看结构图(1)。
总的来说比较蛋疼,因为从来没有使用过mongoDB,从安装,到转为windows服务,设置权限等等,好吧这都是题外话。
在写这个MongoDB版本的时候遇到的一些问题,我先总结下:
1.MongoDb版本是官网最新版3.4.4,官方驱动为2.4.3,首先我的项目是以GUID做为主键,在往MongonDB中插入时遇到的是将GUID生成了MongoDB的LUUID格式产生了这样的格式(2)并且和我的数据库不同(3)当然redis也不同(4)。
a)带着问题我们去解决查了文档发现原来因为bson的键要标识成GUID,并且格式要转为string,既然知道问题了就去解决找到我的GUID主键,如下图(5):
在主键上加上 [BsonId(IdGenerator = typeof(GuidGenerator)), BsonRepresentation(BsonType.String)]这段就可以了,看了下效果确实可以了(6)。
2.但是在测试过程中查询的时候却找不到,一查原来我的数据库redis的id值都不一样,这又是怎么回事?
b)原来mongoDB生成的GUID和C#生成的GUID的进制是不一样的,为了解决这个问题,Google了一下,找到了一个脚本,把这个js脚本放在mongoDB里面执行一下,然后生成的GUID就和数据库的一样了。如图(7):
然后生成的_id就和我数据redis的一样了。(8)(9)
解决完成这些问题后开始写自己的封装类。
希望大家多给出建议,博主也是第一次玩mongoDB,如果有好的学习资源也请推荐给博主。
第一步创建连接:
using MongoDB.Driver;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace KuRuMi.Mio.DoMain.MongoDbCache.MongoDbCommon
{
public class MongoDbManager
{
private static IMongoDatabase db = null;
private static readonly object locker = new object();
/// <summary>
/// 使用单列模式创建连接
/// </summary>
/// <returns></returns>
public static IMongoDatabase CreateDb()
{
if (db == null)
{
lock (locker)
{
if (db == null)
{
MongoClient Client = new MongoClient(MongoDbConfig.Host);
db = Client.GetDatabase(MongoDbConfig.DataBase);
}
}
}
return db;
}
}
}
第二步创建DB:
using MongoDB.Driver;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace KuRuMi.Mio.DoMain.MongoDbCache.MongoDbCommon
{
public class MongoDbBase
{
private IMongoDatabase db = null;
public IMongoDatabase Db { get => db; }
public MongoDbBase()
{
db = MongoDbManager.CreateDb();
}
}
}
然后呢献上自己的封装helper:
using KuRuMi.Mio.DoMain.MongoDbCache.MongoDbCommon;
using MongoDB.Bson;
using MongoDB.Driver;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks; namespace KuRuMi.Mio.DoMain.MongoDbCache.MongoDbCache
{
/// <summary>
/// MongoDb缓存
/// </summary>
public sealed class MongoDbCacheService : MongoDbBase
{
#region 同步
#region 增加
/// <summary>
/// 保存单个对象
/// </summary>
/// <param name="Root"></param>
/// <returns></returns>
public bool AddSignleObject<TAggregateRoot>(TAggregateRoot Root)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
collection.InsertOne(Root);
return true;
}
catch (Exception)
{
return false;
} }
/// <summary>
/// 批量保存多个对象
/// </summary>
/// <param name="Root"></param>
/// <returns></returns>
public bool AddManyObject<TAggregateRoot>(List<TAggregateRoot> Root)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
collection.InsertMany(Root);
return true;
}
catch (Exception)
{
return false;
} }
#endregion #region 删除
/// <summary>
/// 删除单个记录
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="parameter"></param>
/// <returns></returns>
public int DeleteSingleIndex<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return (int)collection.DeleteOne(filter).DeletedCount;
}
catch (Exception e)
{
throw e;
}
}
#endregion #region 查询
/// <summary>
/// 查询单条记录
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="parameter"></param>
/// <returns></returns>
public TAggregateRoot FindSingleIndex<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return collection.Find(filter).FirstOrDefault();
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// 查询整个集合
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <returns></returns>
public List<TAggregateRoot> FindMany<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return collection.Find(filter).ToList();
}
catch (Exception e)
{
throw e;
}
}
#endregion #region 更新
/// <summary>
/// 更新单个值
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <param name="field"></param>
/// <param name="parameter"></param>
/// <returns></returns>
public int UpdateSingle<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter, string name, string parameter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
var set = Builders<TAggregateRoot>.Update.Set(name, parameter);
return (int)collection.UpdateOne(filter, set).ModifiedCount;
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// 更新多个值
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <param name="Root"></param>
/// <param name="property"></param>
/// <param name="replace"></param>
public int UpdateMany<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter, TAggregateRoot Root, List<string> property = null, bool replace = false)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
var type = Root.GetType();
//修改集合
var list = new List<UpdateDefinition<TAggregateRoot>>();
foreach (var propert in type.GetProperties())
{
if (propert.Name.ToLower() != "id")
{
try
{
if (property == null && property.Count < || property.Any(o => o.ToLower() == propert.Name.ToLower()))
{
var replaceValue = propert.GetValue(Root);
if (replaceValue != null)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
else if (replace)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
}
}
catch (Exception)
{
if (property == null)
{
var replaceValue = propert.GetValue(Root);
if (replaceValue != null)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
else if (replace)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
}
} }
}
if (list.Count > )
{
var builders = Builders<TAggregateRoot>.Update.Combine(list);
return (int)collection.UpdateOne(filter, builders).ModifiedCount;
}
return ;
}
catch (Exception e)
{
throw e;
}
}
#endregion
#endregion #region 异步
#region 增加
/// <summary>
/// 异步保存单个对象
/// </summary>
/// <param name="Root"></param>
/// <returns></returns>
public bool AddSignleObjectAsync<TAggregateRoot>(TAggregateRoot Root)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
collection.InsertOneAsync(Root);
return true;
}
catch (Exception)
{
return false;
} }
/// <summary>
/// 批量保存多个对象
/// </summary>
/// <param name="Root"></param>
/// <returns></returns>
public bool AddManyObjectAsync<TAggregateRoot>(List<TAggregateRoot> Root)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
collection.InsertManyAsync(Root);
return true;
}
catch (Exception)
{
return false;
} }
#endregion #region 删除
/// <summary>
/// 异步删除单个记录
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="parameter"></param>
/// <returns></returns>
public int DeleteSingleIndexAsync<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return (int)collection.DeleteOneAsync(filter).Result.DeletedCount;
}
catch (Exception e)
{
throw e;
}
}
#endregion #region 查询
/// <summary>
/// 异步查询单条记录
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="parameter"></param>
/// <returns></returns>
public TAggregateRoot FindSingleIndexAsync<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return collection.FindAsync(filter).Result.FirstOrDefault();
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
/// 异步查询整个集合
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <returns></returns>
public List<TAggregateRoot> FindManyAsync<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
return collection.FindAsync(filter).Result.ToList();
}
catch (Exception e)
{
throw e;
}
}
#endregion #region 更新
/// <summary>
/// 异步更新单个值
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <param name="field"></param>
/// <param name="parameter"></param>
/// <returns></returns>
public int UpdateSingleAsync<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter, string name, string parameter)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
var set = Builders<TAggregateRoot>.Update.Set(name, parameter);
return (int)collection.UpdateOneAsync(filter, set).Result.ModifiedCount;
}
catch (Exception e)
{
throw e;
}
}
/// <summary>
///异步更新多个值
/// </summary>
/// <typeparam name="TAggregateRoot"></typeparam>
/// <param name="filter"></param>
/// <param name="Root"></param>
/// <param name="property"></param>
/// <param name="replace"></param>
public int UpdateManyAsync<TAggregateRoot>(Expression<Func<TAggregateRoot, bool>> filter, TAggregateRoot Root, List<string> property = null, bool replace = false)
{
try
{
var collection = Db.GetCollection<TAggregateRoot>(typeof(TAggregateRoot).Name);
var type = Root.GetType();
//修改集合
var list = new List<UpdateDefinition<TAggregateRoot>>();
foreach (var propert in type.GetProperties())
{
if (propert.Name.ToLower() != "id")
{
try
{
if (property == null && property.Count < || property.Any(o => o.ToLower() == propert.Name.ToLower()))
{
var replaceValue = propert.GetValue(Root);
if (replaceValue != null)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
else if (replace)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
}
}
catch (Exception)
{
if (property == null)
{
var replaceValue = propert.GetValue(Root);
if (replaceValue != null)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
else if (replace)
list.Add(Builders<TAggregateRoot>.Update.Set(propert.Name, replaceValue));
}
} }
}
if (list.Count > )
{
var builders = Builders<TAggregateRoot>.Update.Combine(list);
return (int)collection.UpdateOneAsync(filter, builders).Result.ModifiedCount;
}
return ;
}
catch (Exception e)
{
throw e;
}
}
#endregion
#endregion
}
}
最后是脚本文件:
function HexToBase64(hex) {
var base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
var base64 = "";
var group;
for (var i = 0; i < 30; i += 6) {
group = parseInt(hex.substr(i, 6), 16);
base64 += base64Digits[(group >> 18) & 0x3f];
base64 += base64Digits[(group >> 12) & 0x3f];
base64 += base64Digits[(group >> 6) & 0x3f];
base64 += base64Digits[group & 0x3f];
}
group = parseInt(hex.substr(30, 2), 16);
base64 += base64Digits[(group >> 2) & 0x3f];
base64 += base64Digits[(group << 4) & 0x3f];
base64 += "==";
return base64;
}
function Base64ToHex(base64) {
var base64Digits = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
var hexDigits = "0123456789abcdef";
var hex = "";
for (var i = 0; i < 24;) {
var e1 = base64Digits.indexOf(base64[i++]);
var e2 = base64Digits.indexOf(base64[i++]);
var e3 = base64Digits.indexOf(base64[i++]);
var e4 = base64Digits.indexOf(base64[i++]);
var c1 = (e1 << 2) | (e2 >> 4);
var c2 = ((e2 & 15) << 4) | (e3 >> 2);
var c3 = ((e3 & 3) << 6) | e4;
hex += hexDigits[c1 >> 4];
hex += hexDigits[c1 & 15];
if (e3 != 64) {
hex += hexDigits[c2 >> 4];
hex += hexDigits[c2 & 15];
}
if (e4 != 64) {
hex += hexDigits[c3 >> 4];
hex += hexDigits[c3 & 15];
}
}
return hex;
}
function UUID(uuid) {
var hex = uuid.replace(/[{}-]/g, ""); // remove extra characters
var base64 = HexToBase64(hex);
return new BinData(4, base64); // new subtype 4
}
function JUUID(uuid) {
var hex = uuid.replace(/[{}-]/g, ""); // remove extra characters
var msb = hex.substr(0, 16);
var lsb = hex.substr(16, 16);
msb = msb.substr(14, 2) + msb.substr(12, 2) + msb.substr(10, 2) + msb.substr(8, 2) + msb.substr(6, 2) + msb.substr(4, 2) + msb.substr(2, 2) + msb.substr(0, 2);
lsb = lsb.substr(14, 2) + lsb.substr(12, 2) + lsb.substr(10, 2) + lsb.substr(8, 2) + lsb.substr(6, 2) + lsb.substr(4, 2) + lsb.substr(2, 2) + lsb.substr(0, 2);
hex = msb + lsb;
var base64 = HexToBase64(hex);
return new BinData(3, base64);
}
function CSUUID(uuid) {
var hex = uuid.replace(/[{}-]/g, ""); // remove extra characters
var a = hex.substr(6, 2) + hex.substr(4, 2) + hex.substr(2, 2) + hex.substr(0, 2);
var b = hex.substr(10, 2) + hex.substr(8, 2);
var c = hex.substr(14, 2) + hex.substr(12, 2);
var d = hex.substr(16, 16);
hex = a + b + c + d;
var base64 = HexToBase64(hex);
return new BinData(3, base64);
}
function PYUUID(uuid) {
var hex = uuid.replace(/[{}-]/g, ""); // remove extra characters
var base64 = HexToBase64(hex);
return new BinData(3, base64);
}
BinData.prototype.toUUID = function () {
var hex = Base64ToHex(this.base64()); // don't use BinData's hex function because it has bugs in older versions of the shell
var uuid = hex.substr(0, 8) + '-' + hex.substr(8, 4) + '-' + hex.substr(12, 4) + '-' + hex.substr(16, 4) + '-' + hex.substr(20, 12);
return 'UUID("' + uuid + '")';
}
BinData.prototype.toJUUID = function () {
var hex = Base64ToHex(this.base64()); // don't use BinData's hex function because it has bugs in older versions of the shell
var msb = hex.substr(0, 16);
var lsb = hex.substr(16, 16);
msb = msb.substr(14, 2) + msb.substr(12, 2) + msb.substr(10, 2) + msb.substr(8, 2) + msb.substr(6, 2) + msb.substr(4, 2) + msb.substr(2, 2) + msb.substr(0, 2);
lsb = lsb.substr(14, 2) + lsb.substr(12, 2) + lsb.substr(10, 2) + lsb.substr(8, 2) + lsb.substr(6, 2) + lsb.substr(4, 2) + lsb.substr(2, 2) + lsb.substr(0, 2);
hex = msb + lsb;
var uuid = hex.substr(0, 8) + '-' + hex.substr(8, 4) + '-' + hex.substr(12, 4) + '-' + hex.substr(16, 4) + '-' + hex.substr(20, 12);
return 'JUUID("' + uuid + '")';
}
BinData.prototype.toCSUUID = function () {
var hex = Base64ToHex(this.base64()); // don't use BinData's hex function because it has bugs in older versions of the shell
var a = hex.substr(6, 2) + hex.substr(4, 2) + hex.substr(2, 2) + hex.substr(0, 2);
var b = hex.substr(10, 2) + hex.substr(8, 2);
var c = hex.substr(14, 2) + hex.substr(12, 2);
var d = hex.substr(16, 16);
hex = a + b + c + d;
var uuid = hex.substr(0, 8) + '-' + hex.substr(8, 4) + '-' + hex.substr(12, 4) + '-' + hex.substr(16, 4) + '-' + hex.substr(20, 12);
return 'CSUUID("' + uuid + '")';
}
BinData.prototype.toPYUUID = function () {
var hex = Base64ToHex(this.base64()); // don't use BinData's hex function because it has bugs
var uuid = hex.substr(0, 8) + '-' + hex.substr(8, 4) + '-' + hex.substr(12, 4) + '-' + hex.substr(16, 4) + '-' + hex.substr(20, 12);
return 'PYUUID("' + uuid + '")';
}
BinData.prototype.toHexUUID = function () {
var hex = Base64ToHex(this.base64()); // don't use BinData's hex function because it has bugs
var uuid = hex.substr(0, 8) + '-' + hex.substr(8, 4) + '-' + hex.substr(12, 4) + '-' + hex.substr(16, 4) + '-' + hex.substr(20, 12);
return 'HexData(' + this.subtype() + ', "' + uuid + '")';
}
仓储层的调用:
using KuRuMi.Mio.DoMain.Model.Model;
using KuRuMi.Mio.DoMain.Model.Repositories;
using KuRuMi.Mio.DoMain.Repository.EFRepository;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace KuRuMi.Mio.DoMain.Repository.ModelRepository
{
public class UserRepositoryImpl : RepositoryImpl<User>, IUserRepository
{
public KurumiMioDbContext context => lazy.Context as KurumiMioDbContext;
/// <summary>
/// 登录
/// </summary>
/// <param name="Email"></param>
/// <param name="PassWord"></param>
/// <returns></returns>
public string CheckUser(string Email, string PassWord)
{
try
{
User entity = null;
//MongoDb取
entity = Mongo.FindSingleIndex<User>(a => a.Email == Email);
if (entity == null)
{
//redis取
entity = Redis.RedisString.Value.StringGet<User>(Email);
}
if (entity == null)
{
//数据库取
string sql = "select Id,UserName,Password,email from [User] as a where a.Email ='{0}' and a.PassWord ='{1}'";
string select = string.Format(sql, Email, PassWord);
entity = context.user.SqlQuery(select).FirstOrDefault();
}
return entity.UserName;
}
catch (Exception e)
{
return "";
}
} /// <summary>
/// 保存
/// </summary>
/// <param name="aggregateRoot"></param>
public async override void Add(User aggregateRoot)
{
base.Add(aggregateRoot);
await Redis.RedisString.Value.StringSetAsync(aggregateRoot.Email, aggregateRoot);//保存一份到redis
Mongo.AddSignleObjectAsync(aggregateRoot);//保存一份到mongoDb
} /// <summary>
/// 注册
/// </summary>
/// <param name="info"></param>
/// <returns></returns>
public User GetAll(User info)
{
string sql = "select Id,UserName,Password,email from [User] as a where a.UserName ='{0}' and email ='{1}'";
string select = string.Format(sql, info.UserName, info.Email);
return context.user.SqlQuery(select).FirstOrDefault();
}
}
}
图1:

图2:

图3:

图4:

图5:

图6:

图7:

图8:

图9:

在.net下打造mongoDb基于官方驱动最新版本的更多相关文章
- MongoDB Python官方驱动 PyMongo 的简单封装
最近,需要使用 Python 对 MongodB 做一些简单的操作,不想使用各种繁重的框架.出于可重用性的考虑,想对 MongoDB Python 官方驱动 PyMongo 做下简单封装,百度一如既往 ...
- 基于官方驱动封装mongodb
还是一如既往先把结构图放出来,上上个版本添加了redis的缓存,但是不满足我的需求,因为公司有项目要求是分布式所以呢,这里我就增加了mongoDb进行缓存分布式,好了先看结构图(1). 总的来说比较蛋 ...
- 【转】Win7环境下VS2010配置Cocos2d-x-2.1.4最新版本的开发环境(亲测)
http://blog.csdn.net/ccf19881030/article/details/9204801 很久以前使用博客园博主子龙山人的一篇博文<Cocos2d-x win7+vs20 ...
- Win7环境下VS2010配置Cocos2d-x-2.1.4最新版本的开发环境(亲测)
写这篇博客时2D游戏引擎Cocos2d-x的最新版本为2.1.4,记得很久以前使用博客园博主子龙山人的一篇博文<Cocos2d-x win7+vs2010配置图文详解(亲测)>成功配置 ...
- ubuntu14.04下配置Java环境以及安装最新版本的eclipse
首先是配置JDK 步骤一:下载最新版本的JDK,链接:http://www.oracle.com/technetwork/java/javase/downloads/index.html 步骤二:首先 ...
- 使用MongoDB C#官方驱动操作MongoDB
想要在C#中使用MongoDB,首先得要有个MongoDB支持的C#版的驱动.C#版的驱动有很多种,如官方提供的,samus. 实现思路大都类似.这里我们先用官方提供的mongo-csharp-dri ...
- JBoss7官方下载最新版本
JBoss是全世界开发人员共同努力的成果.一个基于J2EE的开放源码的应用server. 由于JBoss代码遵循LGPL许可,能够在不论什么商业应用中免费使用它.而不用支付费用. 2006年,Jbos ...
- windows下 更新 android studio SDK 到最新版本 解决方案
一.设置代理信息 打开android studio>>File>>Settings>>Appearance&Behavion>>System S ...
- 【MongoDB】 基于C#官方驱动2.2版的封装类
一.前言 最近项目中要用到MongoDB,因此实现做了不少的调研.发现网上很多现有关于MongoDB C#官方驱动的调用方法都是基于1.8版本的,已经不是用了最新的2.2版本.因此我在基于C#官方驱动 ...
随机推荐
- JS Dom节点操作demo!
通过黑马课程的学习,在这里分享一个js Dom中节点操作的小练习 需求:使用js创建一个4*3的表格table. onload = function(){ function c(tagName){ r ...
- storage在IE8下的兼容性写法
storage 本地缓存,这是HTML5的一个非常好用的地方,具体好用在哪,网上可以找到很多,但是我觉得总结的都不是很完整,我建议大家有空的话可以看下JavaScript权威指南这本书,里面对于这个方 ...
- css3 felx布局
一.Flex布局是什么? Flex是Flexible Box的缩写,意为"弹性布局",用来为盒状模型提供最大的灵活性. 任何一个容器都可以指定为Flex布局. [css] .box ...
- css3---线性渐变
.example1 { width: 150px; height: 80px; background: -moz-linear-gradient( top,#ccc,#000); background ...
- (练习题)利用构造器函数实现三个小实例——不使用String()与Array()构造器和Math对象,不使用内建的方法的方法和属性。
1)在String()构造器不存在的情况下自定义一个myString()构造器函数.由于String()不存在,因此您在写构造器函数时不能使用任何属于内建String对象的方法和属性.并让你所创建的对 ...
- 通过 bootloader 向其传输启动参数
作者:Younger Liu, 本作品采用知识共享署名-非商业性使用-相同方式共享 3.0 未本地化版本许可协议进行许可. Linux提供了一种通过bootloader向其传输启动参数的功能,内核开发 ...
- 使用Java POI来选择提取Word文档中的表格信息
通过使用Java POI来提取Word(1992)文档中的表格信息,其中POI支持不同的ms文档类型,在具体操作中需要注意.本文主要是通过POI来提取微软2003文档中的表格信息,具体code如下(事 ...
- TOMCAT的框架结构
Tomcat 服务器是一个免费的开放源代码的Web 应用服务器,属于轻量级应用服务器,在中小型系统和并发访问用户不是很多的场合下被普遍使用,是开发和调试JSP 程序的首选.对于一个初学者来说,可以这样 ...
- 我拖拖拖--H5拖放API基础篇
不要搞错,本文不是讲如何拖地的.看过<javascript精粹>朋友应该知道,他实现拖放的过程比较复杂,现在时代不同了,我们用H5的新的拖放API就能非常方便的实现拖放效果了.最近在园子见 ...
- HDU 2080 夹角有多大II (数学) atan(y/x)分类求角度
夹角有多大II Problem Description 这次xhd面临的问题是这样的:在一个平面内有两个点,求两个点分别和原点的连线的夹角的大小.注:夹角的范围[0,180],两个点不会在圆心出现. ...