Asp.Net function summary

1、DateTime 数字型 

System.DateTime currentTime=new System.DateTime();
1.1 Get the current year, month, day, hour, minute and second
currentTime=System.DateTime.Now;
1.2 Get the current year
int year= currentTime.Year;
1.3 Get the current month
int month=currentTime.Month;
1.4 Get the current day
int day=currentTime.Day;
1.5 Get the current time
int hour =currentTime.Hour;
1.6 Get the current minute
int minute=currentTime.Minute;
1.7 Get the current second
int second=currentTime.Second;
1.8 Get the current millisecond
int Milliseconds = currentTime.Millisecond;
(variable is available in Chinese)

2. Int32.Parse(variable) Int32.Parse("constant")
Character type conversion to 32-bit numeric type

3. Variable.ToString()
Character type 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 (hexadecimal)
12345.ToString("p"); //Generate 1,234,500.00%

4. Variable.Length numeric type
Get the length of the string:
For example: string str="China";
int Len = str.Length; //Len is a self-defined variable, str is the string to be tested Variable name
5. System.Text.Encoding.Default.GetBytes (variable)
Convert character code to bit code
For example: byte[] bytStr = System.Text.Encoding.Default.GetBytes(str);
Then you can get the bit length:
len = bytStr.Length;

6, System. Text.StringBuilder("")
Adding strings, (is the same with the + sign? )
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);
Intercept part of the string, parameter 1 is the starting digit from the left, parameter 2 is Cut out a few.
For example: string s1 = str.Substring(0,2);

8. String user_IP=Request.ServerVariables["REMOTE_ADDR"].ToString();
Get the remote user IP address

9. Get 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 to Session value;
For example, assignment: Session["username"]="Bush";

Value:
Object objName= Session["username"]; String strName=objName.ToString();
Clear: Session.RemoveAll();

11. String str=Request.QueryString["variable"];
Use
hyperlinks to transfer variables. To create a hyperlink in any page:Click
Get the value in the Edit.aspx page: String str=Request.QueryString[ "fdid"];

12. DOC
Object.CreateElement("New node name"); Create
XMLDocument new node
13. Parent node.AppendChild(child node);
Add the newly created child node to the XML document parent node

14. Parent node.RemoveChild(node);
Delete 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, number of digits) - logical type
Check whether the specified position is a null character;
For example:
string str="Chinese People";
Response.Write(char.IsWhiteSpace(str,2)); //The result is: True, No. One character is bit 0, 2 is the third character.

17. char.IsPunctuation('Character') --logical type
Check whether the character is a punctuation mark
For example: Response.Write(char.IsPunctuation('A')); // Return: False

18, (int)'Character'
Convert characters to numbers, check code points, pay attention to single quotes.
For example:
Response.Write((int)'中'); //The result is the Chinese character code: 20013

19, (char) code
Convert numbers to characters, Check the characters represented by the code.
For example:
Response.Write((char)22269); //Return the character "国".

20. Trim()
Clear the spaces before and after the string

21. String variable.Replace("substring", "replace with")
String replacement
For example:
string str="China";
str=str.Replace(" "国","central"); //Replace the character "国" with the character "central"
Response.Write(str); //The output result is "central"

Another example: (This is very practical)

string str="This is