★[Summarize common C #. NET functions and method sets]★

● 1. datetime numeric type
System. datetime currenttime = new system. datetime ();
1.1 take the current year, month, day, hour, minute, second
Currenttime = system. datetime. now;
1.2 get current year
Int year = currenttime. Year;
1.3 take the current month

Int month = currenttime. month;
1.4 get the current day
Int day = currenttime. Day;
1.5 current time
Int = currenttime. hour;
1.6 get the current score
Int = currenttime. minute;
1.7 takes the current second
Int second = currenttime. Second;
1.8 takes the current millisecond
Int millisecond = currenttime. millisecond;
(The variable can be in Chinese)

1.9 display Chinese date -- year, month, and day
String stry = currenttime. tostring ("F"); // seconds not displayed

1.10 use Chinese date to display _ year and month
String strym = currenttime. tostring ("Y ");

1.11 retrieve Chinese Date display _ month/day
String strmd = currenttime. tostring ("M ");

1.12 Chinese year, month, and day
String strymd = currenttime. tostring ("D ");

1.13 get the current time, format: 14: 24
String strt = currenttime. tostring ("T ");

1.14 obtain the current time in the format of 2003-09-23t14: 46: 48
String strt = currenttime. tostring ("S ");

1.15 obtain the current time in the format of 2003-09-23 14: 48: 30z
String strt = currenttime. tostring ("U ");

1.16 The current time. format:
String strt = currenttime. tostring ("G ");

1.17 take the current time, format: Tue, 23 Sep 2003 14:52:40 GMT
String strt = currenttime. tostring ("R ");

1.18 obtain the date and time of the current time n days later
Datetime newday = datetime. Now. adddays (100 );

● 2. int32.parse (variable) int32.parse ("constant ")
Convert string to 32-digit font

● 3. Variable. tostring ()
Convert string to string
12345. tostring ("N"); // generate 12,345.00
12345. tostring ("C"); // generate $12,345.00
12345. tostring ("e"); // generate 1.234500e + 004
12345. tostring ("F4"); // generate 12345.0000
12345. tostring ("X"); // generate 3039 (hexadecimal)
12345. tostring ("p"); // generate 1,234,500.00%

● 4. Variable. Length numeric type
String Length:
For example, string STR = "China ";
Int Len = Str. length; // Len is a custom variable, and STR is the variable name of the string to be tested.

● 5. system. Text. encoding. Default. getbytes (variable)
Convert character code to bit code
For example, byte [] bytstr = system. Text. encoding. Default. getbytes (STR );
Then we can get the bit length:
Len = bytstr. length;

● 6. system. Text. stringbuilder ("")
String addition, (is the same as the + number ?)
For example, system. Text. stringbuilder sb = new system. Text. stringbuilder ("");
SB. append ("China ");
SB. append ("people ");
SB. append ("Republic ");

● 7. Variable. substring (parameter 1, parameter 2 );
Part of the string to be truncated. Parameter 1 is the start number of digits on the left, and parameter 2 is the number of digits to be truncated.
For example, string S1 = Str. substring );

● 8. String user_ip = request. servervariables ["remote_addr"]. tostring ();
Obtain the IP address of a remote user

● 9. Obtain the real IP address of the remote user through the proxy server:
If (request. servervariables ["http_via"]! = NULL ){
String user_ip = request. servervariables ["http_x_forwarded_for"]. tostring ();
} Else {
String user_ip = request. servervariables ["remote_addr"]. tostring ();
}

● 10. session ["variable"];
Access session value;
For example, assign a value: session ["username"] = "";

Value: Object objname = session ["username"];
String strname = objname. tostring ();
Clear: Session. removeall ();

● 11. String STR = request. querystring ["variable"];
Use hyperlinks to send variables.
For example, create a hyperlink on any page: <a href = edit. aspx? Fbid = 23> click </a>
On the edit. ASPX page, set the value to string STR = request. querystring ["fdid"];

● 12. Doc object. createelement ("new node name ");
Create a new node for the XML document

● 13. parent node. appendchild (child node );
Add the new child node to the XML document parent node.

● 14. parent node. removechild (node );
Delete a node

● 15. Response
Response. Write ("string ");
Response. Write (variable );
Output to the page.

Response. Redirect ("url address ");
Jump to the page specified by the URL