C # common code for obtaining remote access IP addresses

1. Obtain the current button:

Private void textbox1_keydown (Object sender, system. Windows. Forms. keyeventargs E)
{
If (E. keycode. tostring () = "enter ")
{

MessageBox. Show (E. keycode. tostring (), "The health you are pressing is :");
}
}

 

2. 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. Convert string type to 32-digit font

Int32.parse (variable) int32.parse ("constant ")

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. Obtain the IP address of a remote user.

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: Click
On the edit. ASPX page, set the value to string STR = request. querystring ["fdid"];

12. Create a new node for the XML document

Doc object. createelement ("new node name ");

13. parent node. appendchild (child node );

Add the new child node to the XML document parent node.

14. delete a node

Parent node. removechild (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

16. Char. iswhitespce (STRING variable, digits) -- Logical type

Check whether the specified position contains null characters;
For example:
String STR = "Chinese people ";
Response. Write (char. iswhitespace (STR, 2); // The result is true. The first character is 0, and the second is the third character.

17. Char. ispunctuation ('characters') -- Logical type

Check whether a character is a punctuation mark.
For example: Response. Write (char. ispunctuation ('A'); // return: false

18. (INT) 'characters'

Convert the character into a number and check the code. Note that it is a single quotation mark.
For example:
Response. Write (INT) 'in'); // The code with the result of a Chinese character: 20013

19. (char) Code

Convert the number into characters and check the characters represented by the Code.
For example:
Response. Write (char) 22269); // return the word "country.

20. Clear spaces before and after the string

Trim ()

21. string variable. Replace ("substring", "Replace ")

String replacement
For example:
String STR = "China ";
STR = Str. Replace ("country", "Central"); // Replace the Chinese character with the central character
Response. Write (STR); // The output result is "Central"

Another example is: (this is very practical)

String STR = "this is