c#基础知识——06

1. new关键字

(1). 创建对象

(2). 隐藏从父类那里继承过来的同名成员, 隐藏的后果就是子类调用不到父类的成员。

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


namespace _06new隐藏从父类那里继承过来的同名成员
{
    class Program
    {
        static void Main(string[] args)
        {
            Student s = new Student();
            s.SayHello();


            Console.ReadKey();
        }
    }


    public class Person
    {
        public void SayHello()
        {
            Console.WriteLine("我是Person类。");
        }
    }


    public class Student:Person
    {
        public new void SayHello()
        {
            Console.WriteLine("我是Student类。");
        }
    }
}

2. Hashtable

using System;
using System.Collections;




namespace _01TestHashtable
{
class MainClass
{
private const string jian = "大家好我是一个程序员";
private const string fan = "大家好我是壹個程序員";


public static void Main (string[] args)
{
Hashtable ht = new Hashtable ();
for(int i = 0; i < jian.Length; i++)
{
if(ht.ContainsKey(jian[i]))
{
continue;
}
ht.Add(jian[i], fan[i]);
}


Console.WriteLine ("请随便输入:");

string input = Console.ReadLine ();
for(int i = 0; i < input.Length; i++)
{
if(ht.ContainsKey(input[i]))
{
Console.Write(ht[input[i]]);
}
else
{
Console.Write(input[i]);
}
}
}
}
}

3. Path

using System;
using System.IO;


namespace _02TestPath
{
class MainClass
{
public static void Main (string[] args)
{
string str = "/Users/liyangwei/Documents/unity5.0.2f3/UnityDownloadAssistant-5.0.2p3.dmg";


string fileName = Path.GetFileName (str);
string fileNameWithoutExtension = Path.GetFileNameWithoutExtension (str);
string extension = Path.GetExtension (str);
string directoryName = Path.GetDirectoryName (str);
string fullPath = Path.GetFullPath (str);
string combine = Path.Combine ("/Users/liyangwei/Documents/unity5.0.2f3", "UnityDownloadAssistant-5.0.2p3.dmg");


Console.WriteLine ("fileName={0}", fileName);
Console.WriteLine ("fileNameWithoutExtension={0}", fileNameWithoutExtension);
Console.WriteLine ("extension={0}", extension);
Console.WriteLine ("directoryName={0}", directoryName);
Console.WriteLine ("fullPath={0}", fullPath);
Console.WriteLine ("combine={0}", combine);
}
}
}

4. File

using System;
using System.IO;
using System.Text;


namespace _03TestFile
{
class MainClass
{
public static void Main (string[] args)
{
FileAppendAllText ();
}


public static void FileAppendAllText()
{
File.AppendAllText ("/Users/liyangwei/Documents/1.txt", "append text to file", Encoding.Default);
Console.WriteLine ("append text to file success.");
}


public static void FileWriteAllText()
{
File.WriteAllText ("/Users/liyangwei/Documents/1.txt", "write to file string", Encoding.Default);
Console.WriteLine ("write string to file success.");
}


public static void FileReadAllText()
{
string str = File.ReadAllText ("/Users/liyangwei/Documents/1.txt", Encoding.Default);
Console.WriteLine (str);
}


public static void FileWriteAllLines()
{
string[] str = {"zhangsan", "lisi", "wangwu"};
File.WriteAllLines ("/Users/liyangwei/Documents/1.txt", str, Encoding.Default);
Console.WriteLine ("write string array to file success.");
}


public static void FileReadAllLines()
{
string[] str = File.ReadAllLines ("/Users/liyangwei/Documents/1.txt", Encoding.Default);
foreach(var item in str)
{
Console.WriteLine (item);
}
}


public static void FileWriteAllBytes()
{
string str = "抽象类特点";
byte[] b = Encoding.Default.GetBytes (str);
File.WriteAllBytes ("/Users/liyangwei/Documents/1.txt", b);
Console.WriteLine ("write string to file success.");
}


public static void FileReadAllBytes()
{
byte[] b = File.ReadAllBytes ("/Users/liyangwei/Documents/抽象类特点.txt");
string str = Encoding.Default.GetString (b);
Console.WriteLine (str);
}


public static void FileOperation()
{
File.Create ("/Users/liyangwei/Documents/new.txt");
Console.WriteLine ("create file success.\n");

File.Copy("/Users/liyangwei/Documents/new.txt", "/Users/liyangwei/Documents/q.txt");
Console.WriteLine ("copy file success.\n");

File.Delete ("/Users/liyangwei/Documents/q.txt");
Console.WriteLine ("delete file success.");
}


}
}