【C#学习笔记】一、基础知识

1.1数据类型（P43）

类型	别名	允许的值
sbyte	System.SByte	-128~127
byte	System.Byte	0~255
short	System.Int16	-32768~32767
ushort	System.Uint16	0~65535
int	System.Int32	-2147483648~2147483647
uint	System.UInt32	0~4294967295
long	System.Int64	-9223372036854775808~9223372036854775807
ulong	System.UInt64	0~18446744073709551615
char	System.Char	一个Unicode字符,0~65535
bool	System.Boolean	true/false
sring	System.String	一组字符
float	System.Single	1.5*10^-45~3.4*10^38
double	System.Double	5.0*10^-324~1.7*10^308
decimal	System.Decimal	1.0*10^-28~7.9*10^28

1.2枚举类型（P97）

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

//【例子1】枚举的基本应用

//1)赋值是可以使用其枚举值赋值，如ct=emCardType.Temic;也可以直接用数值赋值，如ct = (emCardType)3;也可用将字符串经过转换//  赋值给枚举变量,如ct = (emCardType)Enum.Parse(typeof(emCardType), "M1")

//2)使用WritenLine时其实是调用其ToString()方法将其转换为字符串

//3)可以将没有枚举到的数值赋给枚举变量，但ToString()方法显示的字符串为其值

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

enum emCardType:byte

{

Temic,

Em=2,

ID,

M1

}

emCardType ct;

ct=emCardType.Temic ;

Console.WriteLine("ct is {0},value is {1}", ct,(byte)ct);             //显示"ct is Temic,value is 0"

ct++;

Console.WriteLine("ct is {0},value is {1}", ct,(byte)ct);             //显示"ct is 1,value is 1"

ct = (emCardType)Enum.Parse(typeof(emCardType), "M1");

Console.WriteLine("ct is {0},value is {1}", ct, (byte)ct);            //显示"ct is M1,value is 4"

ct = (emCardType)3;

Console.WriteLine("ct is {0},value is {1}", ct.ToString(), (byte)ct); //显示"ct is ID,value is 3"

Console.ReadKey();

1.3数组

1）一维数组定义

int[] myIntArray = { 5, 9, 10, 2, 99 };

int[] myIntArray = new int[5];

int[] myIntArray = new int[5] { 5, 9, 10, 2, 99 };

2）多维数组定义

double[,] hillHeight = new double[3, 4];

double[,] hillHeight = { { 1, 2, 3, 4 }, { 2, 3, 4, 5 }, { 3, 4, 5, 6 } };

3）数组的数组

int [][] myarray

myarray=new int[2][];

myarray[0]=new int[3];

myarray[1]=new int[4];

myarray=new int[3][](new int[]{1,2,3},new int[]{1},new int[]{1,2});

foreach (int[] subarray in myarray)

{

foreach(int nValue in subarray)

Console.WriteLine(nValue);

}

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

//【例子1】数组复制

//若直接使用=号则两个数组引用相同的值,要使用CopyTo方法进行复制

///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

int[] myInt = new int[5]{5,2,1,8,4};

foreach (int i in myInt)

Console.Write(i + ",");

Console.WriteLine("");

int[] myInt2=new int[5];

myInt.CopyTo(myInt2,0);

//myInt2 = myInt;

myInt[1] = 3;

foreach (int i in myInt2)

Console.Write(i + ",");

1.4委托（P137）

【例子1】

class Program

{

delegate double ProcessDelegate(double param1,double param2);

static double Multiply(double param1,double param2)

{

return param1*param2;

}

static double Divide(double param1,double param2)

{

return param1/param2;

}

static void Main(string[] args)

{

ProcessDelegate process;

if (input=="M")    //根据输入的不同将其实例化为不同的函数

process=new processDelegate(Multiply);

else

process=new processDelegate(Divide);

double fRet=process(f1,f2);

}

}

【例子2】

private delegate int mif_selecom(int nCom, int nBaud);

private void button1_Click(object sender, EventArgs e)

{

IntPtr pDll = LoadLibrary("LC32RFRW.dll");

IntPtr pAddressOfFunctionToCall = GetProcAddress(pDll, "mif_selecom");

mif_selecom DoSeleCom = (mif_selecom)Marshal.GetDelegateForFunctionPointer(pAddressOfFunctionToCall,

typeof(mif_selecom));

}