c#制作一个通讯录

利用c#制作一个通讯录，了解数据库的应用

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace WindowsFormsApplication4
{
    internal class Databaseref
    {
        private static Truelore.Common4.Database.IDatabase db = null;
        internal static Truelore.Common4.Database.IDatabase Database
        {
    
          get
             {
            if（db == null）

                 db = new Truelore.Common4.Database.AccessDatabase（“user.mdb“nullfalse）;
            return db;
             }
          }

    }
}

 属性            大小     日期    时间   名称
----------- ---------  ---------- -----  ----
     目录           0  2015-04-17 08:53  通讯录\
     目录           0  2015-04-17 08:54  通讯录\WindowsFormsApplication4\
     文件         962  2015-04-13 10:12  通讯录\WindowsFormsApplication4.sln
     文件       48640  2015-04-17 09:49  通讯录\WindowsFormsApplication4.v11.suo
     文件         524  2015-04-15 15:14  通讯录\WindowsFormsApplication4\App.config
     目录           0  2015-04-16 09:32  通讯录\WindowsFormsApplication4\bin\
     目录           0  2015-04-17 09:49  通讯录\WindowsFormsApplication4\bin\Debug\
     文件       67584  2015-04-16 09:09  通讯录\WindowsFormsApplication4\bin\Debug\Truelore.Common4.dll
     文件      446464  2015-04-17 08:55  通讯录\WindowsFormsApplication4\bin\Debug\user.mdb
     文件       15872  2015-04-17 08:56  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.exe
     文件         524  2015-04-15 15:14  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.exe.config
     文件       38400  2015-04-17 08:56  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.pdb
     文件       22984  2015-04-17 08:55  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.vshost.exe
     文件         524  2015-04-15 15:14  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.vshost.exe.config
     文件         490  2012-06-06 02:06  通讯录\WindowsFormsApplication4\bin\Debug\WindowsFormsApplication4.vshost.exe.manifest
     目录           0  2015-04-15 15:14  通讯录\WindowsFormsApplication4\bin\Release\
     文件         580  2015-04-16 11:16  通讯录\WindowsFormsApplication4\Databaseref.cs
     文件        5183  2015-04-16 17:24  通讯录\WindowsFormsApplication4\Form1.cs
     文件       11410  2015-04-16 17:24  通讯录\WindowsFormsApplication4\Form1.Designer.cs
     文件        7289  2015-04-16 17:24  通讯录\WindowsFormsApplication4\Form1.resx
     目录           0  2015-04-16 09:32  通讯录\WindowsFormsApplication4\obj\
     目录           0  2015-04-17 08:56  通讯录\WindowsFormsApplication4\obj\Debug\
     文件        1308  2015-04-15 17:23  通讯录\WindowsFormsApplication4\obj\Debug\DesignTimeResolveAssemblyReferences.cache
     文件        7266  2015-04-16 18:46  通讯录\WindowsFormsApplication4\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
     文件           0  2015-04-13 10:12  通讯录\WindowsFormsApplication4\obj\Debug\TemporaryGeneratedFile_036C0B5B-1481-4323-8D20-8F5ADCB23D92.cs
     文件           0  2015-04-13 10:12  通讯录\WindowsFormsApplication4\obj\Debug\TemporaryGeneratedFile_5937a670-0e60-4077-877b-f7221da3dda1.cs
     文件           0  2015-04-13 10:12  通讯录\WindowsFormsApplication4\obj\Debug\TemporaryGeneratedFile_E7A71F73-0F8D-4B9B-B56E-8E70B10BC5D3.cs
     目录           0  2015-04-16 09:32  通讯录\WindowsFormsApplication4\obj\Debug\TempPE\
     文件        9216  2015-04-15 15:14  通讯录\WindowsFormsApplication4\obj\Debug\TempPE\userDataSet.Designer.cs.dll
     文件        5745  2015-04-17 08:55  通讯录\WindowsFormsApplication4\obj\Debug\WindowsFormsApplication4.csproj.FileListAbsolute.txt
     文件         975  2015-04-16 17:24  通讯录\WindowsFormsApplication4\obj\Debug\WindowsFormsApplication4.csproj.GenerateResource.Cache
............此处省略14个文件信息