【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));
}
