Asp. 27 sets of functions that are often used in net programming

Asp.net| Programming | function | network

1, DateTime Digital type

System.DateTime currenttime=new System.DateTime ();
1.1 to take the current month and day time currenttime=system.datetime.now seconds;
1.2 Take the current year int year =currenttime.year;
1.3 Take the current month int month =currenttime.month;
1.4 Take the current day int day =currenttime.day;
1.5 =currenttime.hour when the current time int is taken;
1.6 Take the current minute int cent =currenttime.minute;
1.7 takes the current second int second =currenttime.second;
1.8 Take the current millisecond int Ms =currenttime.millisecond;
(Variables available in Chinese)

2, int32.parse (variable) int32.parse ("constant")
Conversion of character to 32-digit number

3, variable. ToString ()
Character conversion 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 (16 binary)
12345.ToString ("P"); Generate 1,234,500.00%

4, variable. Length Number Type
Length of string:
such as: string str= "China";
int Len = str. Length; Len is a custom variable, and STR is the variable name for the measured string.

5, System.Text.Encoding.Default.GetBytes (variable)
codewords conversion to bit code
such as: byte[] bytstr = System.Text.Encoding.Default.GetBytes (str);
Then you can get the bit length:
len = bytstr.length;

6, System.Text.StringBuilder ("")
string addition, (+ is not the same?) ）
such as: System.Text.StringBuilder SB = new System.Text.StringBuilder ("");
Sb. Append ("China");
Sb. Append ("people");
Sb. Append ("Republic");

7, variable. Substring (parameter 1, parameter 2);
Intercepts a portion of the string, parameter 1 is the left starting bit, and the parameter 2 is the Intercept number.
such as: string S1 = str. Substring (0,2);

8, String user_ip=request.servervariables["REMOTE_ADDR"]. ToString ();
Take remote User IP address

9, through the proxy server to take remote user real IP address:
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, assignment: session["username"]= "little Bush";

Take value: Object objname=session["username"];
String strname=objname.tostring ();
Empty: Session.removeall ();

11, String str=request.querystring["variable"];
Transfer variables by using hyperlinks.
If a hyperlink is built on any page: <a href=edit.aspx?fbid=23> Click </a>
Value in edit.aspx page: String str=request.querystring["Fdid"];

12, Doc object. createelement ("new section named");
Create a new node for an XML document

13, the parent node. AppendChild (child nodes);
Add a new child node under the XML Document parent node

14, the parent node. RemoveChild (node);
Delete a node

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

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

16, Char. ISWHITESPCE (string variable, number of digits)--Logical type
Check whether the specified position is empty character;
Such as:
String str= "Chinese people";
Response.Write (Char. Iswhitespace (str,2)); The result is: True, the first character is 0 digits, and 2 is the third character.

17, Char. Ispunctuation (' character ')--logical type
Whether Chag is a punctuation mark
such as: Response.Write (char. Ispunctuation (' A ')); return: False

18, (int) ' character '
Turn the characters into numbers, check the code points, and note the single quotes.
Such as:
Response.Write ((int) ' in '); The result is the code in the word: 20013

19, (char) code
Turn the numbers into characters and look up the characters represented by the code.
Such as:
Response.Write ((char) 22269); Return to the word "state".

20, Trim ()
Clear a space before and after a string

21, string variables. Replace ("substring", "Replace with")
String substitution
Such as:
String str= "China";
Str=str. Replace ("Country", "central"); Change the country word to the word
Response.Write (str); The output is "central"

Another example: (This very practical)

String Str= "This is <script> script";
Str=str. Replace ("<", "<font><</font>"); Replace the left angle bracket with <font> < and </font> (or change to, but it will be restored after the XML has been saved)
Response.Write (str); Display as: "This is <script> script"

If you do not replace the,<script> will not appear, if it is a script, will run, and after the replacement, the script will not run.
The value of this code is that you can disable all HTML tags in one text, display them all, and protect your interactive site.
Concrete implementation: Add your Form submit button script with the following code:
String Strsubmit=label1. Text; Label1 is the ID of the control you want the user to submit data to.
Strsubmit=strsubmit.replace ("<", "<font><</font>");
Then save or output strsubmit.
You can also use this method to easily implement UBB code.

22, Math.max (I,J)
Take the maximum value in I and J
such as int x=math.max (5,10); X will take a value of 10

Add a bit of it. 23. String contrast ...
Add a little.

23, string contrast is generally used: if (STR1==STR2) {}, but there are other ways:

(1),
String str1; str2
Syntax: STR1. EndsWith (STR2); __ The string str1 whether to end with a string str2 returns a Boolean value. For example:
if (str1. EndsWith (STR2)) {Response.Write ("string str1 is terminated" by "+str2+");}

(2),
Syntax: STR1. Equals (STR2); __ Detect string str1 is equal to String str2, return boolean value, usage ibid.

(3),
Syntax Equals (STR1,STR2); __ Detect string str1 is equal to String str2, return boolean value, usage ibid.

24, IndexOf (), LastIndexOf ()
Finds the location of the first (last) occurrence of a specified character or string in a string, returning the index value, such as:
Str1. IndexOf ("word");//Find the index value (position) of the word in str1
Str1. IndexOf ("string");//Find the index value (position) of the first character of the string in str1
Str1. IndexOf ("string", 3,2), and/or from the str1 4th character, look for 2 characters, find the index value of the first character of "string" in str1 (position)

25, Insert ()
Inserts a specified character in a string that specifies the index bit. Such as:
Str1. Insert (1, "word"); in str1 the second word entered prompt inserted "word", if str1= "China", inserted after "Chinese word state";

26, PadLeft (), PadRight ()
Adds a space or char character to the left (or right) of the string so that the string reaches the specified length, such as:
<%
String str1= "Chinese";
Str1=str1. PadLeft (10, ' 1 '); No second parameter is plus space
Response.Write (STR1); The result is "1111111 Chinese" with a string length of 10.
%>

27. Remove ()
Deletes the specified number of characters starting at the specified location
String comparisons are generally used: if (STR1==STR2) {}, but there are other ways: