27 function sets that are frequently used in ASP. NET Programming

ASP. net is a new generation of Microsoft. on the Net Platform Architecture, the Common Language Runtime is used to provide users with a powerful programming framework for enterprise-level Web application services at the backend of the server. The following lists 27 common functions in ASP. NET:

1. datetime numeric type

CopyCode The Code is as follows: system. datetime currenttime = new system. datetime ();
1.1 take the current year, month, day, hour, minute, second currenttime = system. datetime. now;
1.2 take the current year int year = currenttime. Year;
1.3 The current month int month = currenttime. month;
1.4 Use the int day of the current day = currenttime. Day;
1.5 when the current int value is used: = currenttime. hour;
1.6 take the current minute Int = currenttime. minute;
1.7 take the current second int second = currenttime. Second;
1.8 take the current millisecond int millisecond = currenttime. millisecond;
(The variable can be in Chinese)

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

Convert string to 32-digit font

3. Variable. tostring ()Copy codeThe Code is as follows: Convert string type to string type
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

Copy code The Code is as follows: Get the 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)

Copy code The Code is as follows: Convert the code into a 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 ("")

Copy code The Code is as follows: String addition, (is the same with 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 );

Copy code The Code is as follows: Part of the string to be truncated. Parameter 1 is the left start digit, and parameter 2 is the number of truncated digits.
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:Copy codeThe Code is as follows: 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"];

Copy code The Code is as follows: access the 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"];

Copy code The Code is as follows: 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. 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

Copy code The Code is as follows: 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

Copy code The Code is as follows: 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 typeCopy codeThe Code is as follows: Check whether the character is a punctuation mark
For example: Response. Write (char. ispunctuation ('A'); // return: false

18. (INT) 'characters'

Copy code The Code is as follows: Convert the character into a number and check the Code Point. 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

Copy code The Code is as follows: Convert the number into a character and check the characters represented by the Code.
For example:
Response. Write (char) 22269); // return the word "country.

;

20. Trim ()

Clear leading and trailing Spaces

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

Copy code The Code is as follows: 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 A <SCRIPT> script ";
STR = Str. replace ("<", "<font> </font> "); // Replace the left angle brackets with <font> and </font> (or replace them with <, but it is estimated that after saving the XML, it will be restored again)
Response. Write (STR); // display as: "This is a <SCRIPT> script"
If not replaced, <SCRIPT> is not displayed. If it is a script, it runs. If it is replaced, the script does not run.
The value of this Code is that you can invalidate and display all HTML tags in a text file to protect your interactive websites.
Specific implementation: Add the following code to your form submission button script:
String strsubmit = label1.text; // label1 is the Control ID for you to submit data.
Strsubmit = strsubmit. Replace ("<", "<font> </font> ");
Then save or output strsubmit.
This method can also be used to easily implement the UBB code.
22. Math. Max (I, j)

Copy code The Code is as follows: Take the maximum value in I and j.
For example, int x = math. Max (5, 10); // X, the value is 10.

Add one.

23. String comparison is generally used: If (str1 = str2) {}, but there are other methods:

Copy code The Code is as follows: (1 ),
String str1; str2
// Syntax: str1.endswith (str2); _ check whether str1 ends with str2 and returns a Boolean value. For example:
If (str1.endswith (str2) {response. Write ("string str1 ends with" + str2 + ");}
(2 ),
// Syntax: str1.equals (str2); _ check whether str1 is equal to str2. Return a Boolean value, which is the same as the preceding syntax.
(3 ),
// Syntax equals (str1, str2); _ checks whether str1 is equal to str2 and returns a Boolean value.

24. indexof (), lastindexof ()

Copy code The Code is as follows: Find the position where the specified character or string appears for the first time (the last time) in the string and return the index value, for example:
Str1.indexof ("word"); // search for the index value (location) of the word in str1)
Str1.indexof ("string"); // search for the index value (location) of the first character of "string" in str1)
Str1.indexof ("string", 4th); // query the index value (location) of the first character of the "string" in str1 for 2 characters starting from str1 characters)
[Code]

25. insert ()

Insert the specified character into the specified index position in the string. For example:
Str1.insert (1, "word"); Insert "word" to the second character of str1. If str1 = "China", it is inserted as "Chinese country ";

26. padleft (), padright ()

[Code]
Add a space or a specified char character to the left (or right) of the string so that the string reaches the specified length, for example:
<%
String str1 = "Chinese ";
Str1 = str1.padleft (10, '1'); // No second parameter is added with Space
Response. Write (str1); // The result is "1111111 Chinese" and the string length is 10.
%>

27. Remove ()Copy codeThe Code is as follows: delete a specified number of characters from the specified position
String comparison is generally used: If (str1 = str2 ){}