Summary of Enum in C #

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1. Definition of EnumEnum Fabric

{Cotton = 1, silk = 2, wool = 4, rayon = 8, other = 128}

2. Conversion between symbol names and constant values Fabric Fab = fabric. cotton; int fabnum = (INT) Fab; // convert to a constant value. Mandatory conversion is required. Fabric fabstring = (fabric) 1; // convert a constant value to a symbolic name. If tostring () is used (Fabric) 1). tostring (), note that there must be brackets. String fabtype = Fab. tostring (); // display the symbol name string fabval = Fab. tostring (" D "); // Display a constant value 3. Obtain all symbolic names (For details, refer to the enum class) Public Enum myfamily {yangzhiping = 1, guanguiqin = 2, yanghaoran = 4, Liwei = 8, guanguizhi = 16, lisiwen = 32,
Lisihua = 64,} foreach (string s in Enum. getnames (Typeof (Myfamily) {console. writeline (s );} 4. Process enumeration as a bit flag

According to the two examples below, on the one hand, setting the flag [flags] or [flagsattribute] indicates that the symbol name must be listed. On the other hand, you can use force conversion to list the symbol names, convert a number Symbol name. Inaccurate. Let's take a look at the example below. Note:

Example 1: Fabric Fab = fabric. cotton | fabric. rayon | fabric. silk; console. writeline ("myfabric = {0}", FAB); // output: fabric. cotton | fabric. rayon | fabric. silk;

Example 2: Class flagsattributedemo {// define an Enum without flagsattribute. Enum singlehue: Short {black = 0, Red = 1, Green = 2, Blue = 4 };
// Define an Enum with flagsattribute. [flagsattribute]
Enum multihue: Short {black = 0, Red = 1, Green = 2, Blue = 4 };
Static void main () {console. writeline ("this example of the flagsattribute attribute \ n" + "generates the following output. "); console. writeline ("\ Nall possible combinations of values of an \ n" + "Enum without flagsattriations: \ n"); // display all possible combinations of values. For (INT val = 0; Val <= 8; Val ++) Console. writeline ("{0, 3}-{1}", Val, (singlehue) Val). tostring ()); Console. writeline ("\ Nall possible combinations of values of an \ n" + "Enum with flagsattriations: \ n"); // display all possible combinations of values. // also display an invalid value. For (INT val = 0; Val <= 8; Val ++) Console. writeline ("{0, 3}-{1}", Val, (multihue) Val). tostring ()); }}
/* This example of the flagsattribute attribute generates the following output.
All possible combinations of values of an Enum without flagsattribute:
0-black 1-Red 2-green 3-3 4-Blue 5-5 6-6 7-7 8-8
All possible combinations of values of an Enum with flagsattriations:
0-black 1-Red 2-green 3-red, green 4-Blue 5-red, blue 6-green, blue 7-red, green, blue 8-8 */

5. enumeration is used as a function parameter. It is often used in combination with a switch. The following example

Public static double getprice (fabric FAB)

{Switch (FAB)

{Case fabric. Cotton: Return (3.55 );

Case fabric. Silk: Return (5.65 );

Case fabric. wool: Return (4.05 );

Case fabric. Rayon: Return (3.20 );

Case fabric. Other: Return (2.50 );

Default: Return (0.0 );}}

6. The above 3.1 complete examples

// 1. Definition of Enum public Enum fabric: short

{Cotton = 1, silk = 2, wool = 3, rayon = 8, other = 128}

// Pass enumeration as a parameter public static double getprice (fabric FAB)

{Switch (FAB)

{

Case fabric. Cotton: Return (3.55 );

Case fabric. Silk: Return (5.65 );

Case fabric. wool: Return (4.05 );

Case fabric. Rayon: Return (3.20 );

Case fabric. Other: Return (2.50 );

Default: Return (0.0 );}}

Public static void main ()

{Fabric Fab = fabric. cotton;

Int fabnum = (INT) Fab;

String fabtype = Fab. tostring ();

String fabval = Fab. tostring ("D ");

Double cost = getprice (FAB );

Console. writeline ("fabnum = {0} \ nfabtype = {1} \ nfabval = {2} \ n", fabnum, fabtype, fabval );

Console. writeline ("cost = {0}", cost );
}

7. Use of Enum class

Enum. isdefinde and enum. parse are often used together to determine whether a value or symbol is an enumeration member and then create an instance. Enum. getname prints the value of a member. enum. getnames prints the value of all members. Note:Typeof. This is important.

Public Enum myfamily

{Yangzhiping = 1, guanguiqin = 2, yanghaoran = 4, Liwei = 8, guanguizhi = 16, lisiwen = 32,
Lisihua = 64 ,}

String S = "yanghaoran ";

If (enum.Isdefined ( Typeof (Myfamily), S) {myfamily F = (Myfamily) Enum. Parse (Typeof (myfamily), S); getmyfamily (f); console. writeline ("the name is:" + enum. Getname ( Typeof (Myfamily), 2); string [] SA = enum. Getnames (Typeof (myfamily ));
Foreach (string SS in SA) {console. writeline (SS );}}