using System;
using System.IO;
using System.Net;
using System.Text;
using System.Reflection;
using System.Collections;
using System.Collections.Generic;
using System.Text.RegularExpressions;
namespace C_Notes
{
class Program
{
static void Main_String_Basix(string[] args)
{
//How to run C# in VS Code?
/*
step 0: create a null folder and open it in vscode
step 1: dotnet new console
step 2: dotnet restore
step 3: dotnet run
*/
Console.WriteLine("Hello World!");
////////////////////////////////////
//Common string is unchangable
string str = "hello//:www.world.edu.uk";
int result = str.CompareTo("hello");//return 0 when 2 strings are the same
result = string.Compare(str, "hello");//same as above
Console.WriteLine(result);//0
result = str.CompareTo("hallo");//return 1 when the first different letter-index in string is lager
result = string.Compare(str, "hallo");//same as above
Console.WriteLine(result);//1
result = str.CompareTo("hillo");//return -1 when the first different letter-index in string is smaller
result = string.Compare(str, "hillo");//same as above
Console.WriteLine(result);//-1
string newStr = str.Replace("ll", "ff");//replacement won't change original string
Console.WriteLine($"Original:{str}. New:{newStr}.");//original string is still the originale one
string targetString = "world";
int indexOfTargetString = str.IndexOf(targetString);//returns the index of the first letter in target string
Console.WriteLine($"index of {targetString} is {indexOfTargetString}");//12
indexOfTargetString = str.IndexOf(targetString + "X");//return -1 if no target string was found
Console.WriteLine($"index of {targetString + "X"} is {indexOfTargetString}");//-1
//Use them in comprohensive way such as below:
if (!str.IndexOf(targetString).Equals(-1))
{
string m_targetString = str.Substring(str.IndexOf(targetString), targetString.Length);
Console.WriteLine($"my target string from the sentence: {m_targetString}");
}
////////////////////////////////////
//Common string is unchangable and may cause wastes
//We use string builder to create strings which often changes
StringBuilder stringBuilder = new StringBuilder("Hello World!");
StringBuilder stringBuilder2 = new StringBuilder(100);//open string space size of 100, space will be extended if exceeds
StringBuilder stringBuilder3 = new StringBuilder("Hello World!", 100);//initialize and open 100 soze of string space, space will be extended if exceeds
Console.WriteLine(stringBuilder);
stringBuilder.Append("---By Alexander");//Effective
Console.WriteLine(stringBuilder);
stringBuilder.Insert(5, "*a lamp inserted*");
Console.WriteLine(stringBuilder);
stringBuilder.Replace("Hello", "Conia sayo");//This will affect the original string
Console.WriteLine(stringBuilder);//original string has been changed
stringBuilder.Clear();
Console.WriteLine(stringBuilder);
}
//////////////////////////////////////////////
static void Main_Regx_Basix(string[] args)
{
// if (IsInputMatchesNumber())
if (IsInputMatchesNumberByRegx())
{
Console.WriteLine("Input charectors are all numbers.");
}
else
{
Console.WriteLine("Input charectors are not pure numbers.");
}
}
//Common way to judge whether a string is pure numbers or not
static bool IsInputMatchesNumber()
{
Console.Write("Please input your password: ");
string str = Console.ReadLine();
bool isMatch = true;
for (int i = 0; i < str.Length; i++)
{
if (str[i] < '0' || str[i] > '9')
{
isMatch = false;
break;
}
}
return isMatch;
}
//Use regular expressions to judge, result is the same as above
static bool IsInputMatchesNumberByRegx()
{
Console.Write("Please input your password: ");
string str = Console.ReadLine();
//Regular expression always come with @
// @ means "do not convert in string"
// ^ means "start from"
// $ means "end at"
// * means "has any"
// d means "number"
string pattern = @"^d*$";
return Regex.IsMatch(str, pattern);
}
//////////////////////////////////////////////
static void Main_Delegate_Basix(string[] args)
{
int x = 100;
int y = 300;
//Get the pointer of the function "ToStirng" and apply it to the varible getAString
GetAString getAString = new GetAString(x.ToString);
GetAString getAString2 = x.ToString;//2nd Way to define: same as above
Console.WriteLine(getAString());//Usable while calling by varible "getAString"
Console.WriteLine(getAString2());//Usable while calling by varible "getAString2"
string str = getAString.Invoke();//2nd way to call
string str2 = getAString2.Invoke();//2nd way to call
Console.WriteLine(str);
Console.WriteLine(str2);
MethodHolder myMethod = new MethodHolder(y.ToString);
Console.WriteLine(AnotherMethod(myMethod));
}
//Signature of the delegate
delegate void VoidFuncWithOneParameter(int parameter);
delegate int IntFuncWithOneParameter(int parameter);
delegate int IntFuncWithTwoParameters(int parameterInt, string parameterStr);
delegate string GetAString();//This will be treated as a class
/*!IMPORTANT!*/
delegate string MethodHolder();
//delegate can be used to send a method as parameter to another method
static string AnotherMethod(MethodHolder method)
{
return method();//just like a callback-function in JS
}
//////////////////////////////////////////////
static void Main_Action_Basix(string[] args)
{
//Action is a delegate which points to a void method without parameters
Action voidMethod = Method;
voidMethod();
//Action<type of parameter> can points to a void method with parameters
Action<int> voidMethodWithParameters = MethodWithParameters;
voidMethodWithParameters(5);
}
static void Method()
{
Console.WriteLine("This is a method which returns nothing.");
}
static void MethodWithParameters(int parameter)
{
if (parameter > 0)
{
for (int i = 0; i < parameter; i++)
{
Console.WriteLine("This is a void method with a parameter.");
}
}
else
{
Console.WriteLine("Parameter should be greater than 0");
}
}
//////////////////////////////////////////////
static void Main_Func_Basix(string[] args)
{
//The last parameter in "Func" is the type of return-value the method
//while the former parameters are all the parameters' type of the target method
Func<string, int, bool, float> matureMethod = MatureMethod;
matureMethod("Hello world!", 6, true);
//The single parameter means the return-value of the method
Func<bool> simpleMethod = SimpleMethod;
Console.WriteLine(simpleMethod());
}
static float MatureMethod(string parameterStr, int parameterInt, bool parameterBool)
{
if (parameterBool && parameterInt > 0)
{
for (int i = 0; i < parameterInt; i++)
{
Console.WriteLine($"{i} : {parameterStr}");
}
return 0.618f;
}
else
{
Console.WriteLine("3rd parameter is set to false or the 2nd parameter is smaller than 0");
return 3.14f;
}
}
static bool SimpleMethod()
{
return true;
}
//////////////////////////////////////////////
//Little utils
//////////////////////////////////////////////
static void Main_TestUtils(string[] args)
{
Console.WriteLine(CheckPageUrl("www.baidu.com"));
Console.WriteLine(CheckPageUrl("http://www.baidu.com"));
Console.WriteLine(WriteLog.WriteMessage("hello!"));
}
/// <summary>
/// 判断网址是否可以访问
/// </summary>
/// <param name="Url"></param>
/// <returns></returns>
protected static bool CheckPageUrl(string url)
{
bool result = false;
try
{
if (url.IndexOf("http").Equals(-1))
{
url = "http://" + url;
// Console.WriteLine(url);
}
HttpWebRequest myHttpWebRequest = (HttpWebRequest)WebRequest.Create(url);
myHttpWebRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; Trident/7.0; rv:11.0) like Gecko";
myHttpWebRequest.Method = "GET";
HttpWebResponse myHttpWebResponse = (HttpWebResponse)myHttpWebRequest.GetResponse();
if (myHttpWebResponse.StatusCode == HttpStatusCode.OK)
{
result = true;
}
myHttpWebResponse.Close();
}
catch
{
result = false;
}
return result;
}
}
public class WriteLog
{
/// <summary>
/// 将错误写入文件中
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="exception">发生的异常</param>
public static void WriteErorrLog(string fileName, Exception exception)
{
if (exception == null) return; //ex = null 返回
DateTime dt = DateTime.Now; // 设置日志时间
string time = dt.ToString("yyyy-MM-dd HH:mm:ss"); //年-月-日 时：分：秒
string logName = dt.ToString("yyyy-MM-dd"); //日志名称
string logPath = Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, Path.Combine("log", fileName)); //日志存放路径
string log = Path.Combine(logPath, string.Format("{0}.log", logName)); //路径 + 名称
try
{
FileInfo info = new FileInfo(log);
if (info.Directory != null && !info.Directory.Exists)
{
info.Directory.Create();
}
using (StreamWriter write = new StreamWriter(log, true, Encoding.GetEncoding("utf-8")))
{
write.WriteLine(time);
write.WriteLine(exception.Message);
write.WriteLine("异常信息：" + exception);
write.WriteLine("异常堆栈：" + exception.StackTrace);
write.WriteLine("异常简述：" + exception.Message);
write.WriteLine("
----------------------------------
");
write.Flush();
write.Close();
write.Dispose();
}
}
catch { }
}
/// <summary>
/// 将终端内容打印到文件中
/// </summary>
/// <param name="fileName">文件名</param>
/// <param name="message">所要写入的内容</param>
public static bool WriteMessage(string fileName, string message)
{
//ex = null 返回
DateTime dt = DateTime.Now; // 设置日志时间
string time = dt.ToString("yyyy-MM-dd HH:mm:ss"); //年-月-日 时：分：秒
string logName = dt.ToString("yyyy-MM-dd"); //日志名称
string logPath = Path.Combine(System.AppDomain.CurrentDomain.BaseDirectory, Path.Combine("log", fileName)); //日志存放路径
string log = Path.Combine(logPath, string.Format("{0}.log", logName)); //路径 + 名称
try
{
FileInfo info = new FileInfo(log);
if (info.Directory != null && !info.Directory.Exists)
{
info.Directory.Create();
}
using (StreamWriter write = new StreamWriter(log, true, Encoding.GetEncoding("utf-8")))
{
write.WriteLine(time);
write.WriteLine("信息：" + message);
write.WriteLine("
----------------------------------
");
write.Flush();
write.Close();
write.Dispose();
}
return true;
}
catch (Exception e)
{
WriteErorrLog("WriteMessageException", e);
return false;
}
}
/// <summary>
/// 将错误写入文件中
/// </summary>
/// <param name="exception">发生的错误</param>
/// <param name="message">需要写入的消息</param>
public static bool WriteErorrLog(Exception exception, string message)
{
if (exception == null) return false; //ex = null 返回
DateTime dt = DateTime.Now; // 设置日志时间
string time = dt.ToString("yyyy-MM-dd HH:mm:ss"); //年-月-日 时：分：秒
string logName = dt.ToString("yyyy-MM-dd"); //日志名称
string logPath = System.AppDomain.CurrentDomain.BaseDirectory; //日志存放路径
string log = Path.Combine(Path.Combine(logPath, "log"), string.Format("{0}.log", logName)); //路径 + 名称
try
{
FileInfo info = new FileInfo(log);
if (info.Directory != null && !info.Directory.Exists)
{
info.Directory.Create();
}
using (StreamWriter write = new StreamWriter(log, true, Encoding.GetEncoding("utf-8")))
{
write.WriteLine(time);
write.WriteLine(exception.Message);
write.WriteLine("异常信息：" + exception);
write.WriteLine("异常堆栈：" + exception.StackTrace);
write.WriteLine("异常简述：" + message);
write.WriteLine("
----------------------------------
");
write.Flush();
write.Close();
write.Dispose();
}
return true;
}
catch (Exception e)
{
WriteMessage("ErrorLogException", e.ToString());
return false;
}
}
/// <summary>
/// 将消息写入文件
/// </summary>
/// <param name="message">需要写入的内容</param>
public static bool WriteMessage(string message)
{
//ex = null 返回
DateTime dt = DateTime.Now; // 设置日志时间
string time = dt.ToString("yyyy-MM-dd HH:mm:ss"); //年-月-日 时：分：秒
string logName = dt.ToString("yyyy-MM-dd"); //日志名称
string logPath = System.AppDomain.CurrentDomain.BaseDirectory; //日志存放路径
// System.Console.WriteLine(logPath);
string log = Path.Combine(Path.Combine(logPath, "log"), string.Format("{0}.log", logName)); //路径 + 名称
try
{
FileInfo info = new FileInfo(log);
if (info.Directory != null && !info.Directory.Exists)
{
info.Directory.Create();
}
using (StreamWriter write = new StreamWriter(log, true, Encoding.GetEncoding("utf-8")))
{
write.WriteLine(time);
write.WriteLine("信息：" + message);
write.WriteLine("
----------------------------------
");
write.Flush();
write.Close();
write.Dispose();
}
return true;
}
catch (Exception e)
{
WriteErorrLog("WriteMessageException", e);
return false;
}
}
}
}