Some summary and collected materials in the process of learning C # Hope to be useful to beginners

Dotnet_csharpOfSparonSummary

 

It is best for beginners to use the single-step failover method (F11) To runProgramThis helps to understand the internal operating system of the program.

 

 

Logical expression Operators...2

Normalization of positive table...2

Nested class Operator...3

Construction...3

Proxy (Commission)...4

Establish a database connection...4

 

Logical expression Operators

Operands1	Operands2	Operator	Result	Rules
True	True	&& And Logic and	True	One isFalseThat isFalse
True	False		False
False	True		False
False	False		False
True	True	| Or Logic or	True	At least one operand isTrue
True	False		True
False	True		True
False	False		False
True	True	^ XOR Logic exclusive or	False	The two operands are the sameFalse
True	False		True
False	True		True
False	False		False

 

 

Normalization of positive table

Regular form single character type

Type	Generic form	Description
\ D	[0-9]	Any number
\ D	[^ 0-9]	Any non-numeric word
\ WS	[A-Za-z0-9 _]'	Any word character
\ W	'[^ A-Za-z0-9 _]'	Any non-single-word characters
\ S	[\ F \ n \ r \ t \ v]	Any blank characters
\ SW	[^ \ F \ n \ r \ t \ v]	Any non-blank characters

 

Character and set character

Format	Description
.	Any character except the limit line
\ P {UC}	UnicodeCharacter TypeUCAny character in
[Abcxyz]	Any delimiter in the Set
\ P {UC}	AnyUnicodeCharacter TypeUCCharacter
[^ Abcxyz]	Any character other than this delimiter

 

Characters

Format	Description
*	0Or more characters
+	1Or more characters
?	0Or1Characters
{N}	ExactlyNCharacters
{N ,}	At leastNCharacters
{N, m}	At leastNBut not many charactersMCharacters

 

Location (atomic zero degree) Statement

Format	Description
^	Start of a string or start of a new line
\ Z	The end of the string, including the delimiter.
$	The character string before or after the line.
\ G	Starting from where the last matching ended
\	Start of a string
\ B	Matching of Characters in the character field (alphanumeric and non-alphanumeric)
\ Z	End of the string before the delimiter
\ B	It is not a single-byte character.

 

 

Nested class Operator

marker	permission restriction
Public	unrestricted use of classes
protected	only this inclusion class ( containing Class ) this nested type can be used only for derived classes
private	This inclusion type has the right to allow unauthorized access to nested classes
internal	This nested type can be used only for the proxies in the same Assembly
protected internal	All agents in the same program and from this external Assembly that contains classes are this nested type can be used

 

Construction

 

 

Proxy (Commission)

Establish unicast proxy (Commission) step by step

1.Protected internalDelegateMydelegate(StringName );//Declare a proxy and specify the incoming numeric type

2.Public VoidProcessname (MydelegateMydelegateprocessname)
{
If(Name! = NULL)
// Calling the delegate:
Mydelegateprocessname (name );
}

3.Processname (New Mydelegate(Mydelegateprocessname));

4.Static Void Mydelegateprocessname (StringName)//When creating a method for processing the agent, the parameter number must be consistent with the specified type when the agent is specified.
{
Console. Writeline ("The process name is {0 }", Name );
}

 

 

 

 

 

Establish a database connection

Procedure for establishing a database connection

1.StringConnectionstring ="Integrated Security = sspi; Data Source = IP; initial catalog = databasename ;";//You can also setIntegrated Security = sspi;ChangeUid = username; Pwd = password;

2.SqlconnectionConnection =New sqlconnection(Connectionstring );//Input a database connection string to construct a database connection object

3.String sqlstr = "select * from products ";//DefinitionSQLDatabase query string

4.SqlcommandSelectcommand =New sqlcommand(Sqlstr, connection );//Construct a database connection object

5.SqldataadapterDataadapter =New sqldataadapter(Selectcommand );//Construct a database Adapter

6.Connection. Open();//Open Database

7.DatasetProductsds =New Dataset();//Define a data set

8.Dataadapter. Fill(Productsds );//UseDataadapterFill data set

9.Connection. Close();//Because data sets are used, they can be viewed offline.

 

 

Establish remote host connection

1.Private SocketSocket_c2s =New Socket(Addressfamily. InterNetwork,Sockettype. Stream,Protocoltype. TCP );//Declare a connection object

2.IPaddressMyip =IPaddress. parse("172.16. 18.1 " );//UseIPAddress StructureIPaddressObject

3.IpendpointIPE =New Ipendpoint(Myip,Convert. toint32(" 80 " ));//Passing the connection port number into the object

4.Socket_c2s.Connect(IPE );//Try to connect

5./*Accept connection, read data, send data referenceMyqqserverProgram*/