<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="12.0" DefaultTargets="Build"
  xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props"
    Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
  <PropertyGroup>
    <Configuration Condition=" '$(Configuration)' == ''     ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    {123334}
    ...
    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
  </PropertyGroup>
...
</Project>

文字列定数を定義する時に @マークを付けるとエスケープシーケンスが不要になる。

string str1 = "C:\\Windows\\Hoge.txt";

string str2 = @"C:\Windows\Hoge.txt";

if (String.Compare(str1, str2) == 0)
  System.Console.WriteLine("str1 = str2");

文字列定数を定義する時に @マークを付けると複数行に文字列を記述する時に便利
※ PHP等のヒアドキュメント的な使い方と同じで here stringと言う。

string str1 = "This is the first line of my string.\n" +
              "This is the second line of my string.\n" +
              "This is the third line of the string.\n";

string str2 = @"This is the first line of my string.
This is the second line of my string.
This is the third line of the string.";

String.Compare(str1, str2)
　str1 < str2 = -1
　str1 = str2 =  0
　str1 > str2 =  1

String.Compare("2014/01/01 00:00:00", "2014/01/01 00:00:00") = 0
String.Compare("2014/01/01 00:00:01", "2014/01/01 00:00:00") = 1
String.Compare("2014/01/01 00:00:00", "2014/01/01 00:00:01") = -1
String.Compare("2014/01/01 23:00:00", "2014/01/02 00:00:00") = -1
String.Compare("2014/01/01 00:00:00", "2014/01/02")          = -1
String.Compare("2014/01/01",          "2014/01/02 00:00:00") = -1
String.Compare(null,                  "")                    = -1
String.Compare(null,                  null)                  = 0
String.Compare("",                    null)                  = 1

DateTime dt = DateTime.Now;
dt.ToString(); → "2014/11/22 12:34:56"

dt += new TimeSpan(1, 2, 3); // 1時間 2分 3秒を足す
dt.ToString(); → "2014/11/22 13:36:59"