[C # Study Notes] I. Basic knowledge,

[C # Study Notes] I. Basic knowledge,
1.1 data type (P43)

Type	Alias	Allowed value
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	A Unicode character, ranging from 0 ~ 65535
Bool	System. Boolean	True/false
Sring	System. String	A group of characters
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 Enumeration type (P97)

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

// [Example 1] basic application of enumeration

// 1) You can use its enumerated values to assign values, such as ct = emCardType. temic; you can also directly assign values using numeric values, such as ct = (emCardType) 3; you can also convert the string and assign it to the enumerated variable, such as ct = (emCardType) Enum. parse (typeof (emCardType), "M1 ")

// 2) When WritenLine is used, the ToString () method is called to convert it to a string.

// 3) the enumerated value can be assigned to the enumerated variable, but the string displayed by the ToString () method is its value.

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

Enum emCardType: byte

{

Temic,

Em = 2,

ID,

M1

}

EmCardType ct;

Ct = emCardType. Temic;

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

Ct ++;

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

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

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

Ct = (emCardType) 3;

Console. writeLine ("ct is {0}, value is {1}", ct. toString (), (byte) ct); // display "ct is ID, value is 3"

Console. ReadKey ();

Array 1.3

1) One-dimensional array Definition

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

Int [] myIntArray = new int [5];

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

2) multi-dimensional array Definition

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

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

3) array Array

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 );

}

 

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

// [Example 1] copying Arrays

// If the = sign is used directly, the two arrays reference the same value. You must use the CopyTo Method for copying.

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

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 Delegation)

[Example 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") // instantiate it as a different function based on the input.

Process = new processDelegate (Multiply );

Else

Process = new processDelegate (Divide );

Double fRet = process (f1, f2 );

}

}

 

[Example 2]]

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

Private void button#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 ));

}