C # Indexer Method

Tag: Value person returns the declaration ace using a two-bit array generic class names

Use the index operation [] to access the individual subkeys contained in a standard array.

Definition: The method of accessing a subkey using the index operator [] is called an indexer method

1. Custom Indexer Method (this):

 Public classpeoplecollection:ienumerable{PrivateArrayList arpeople=NewArrayList (); //Custom Indexer for class        PublicPerson This[intIndex//similar to attribute declarations except for multiple this keywords      {             Get{return(person) arpeople[index];} Set{Arpeople.insert (index,value);}//using the ArrayList Insert () method      }}

2. The generic type directly supports the indexer method:

List<person> mypeople=NewList<person>(); Mypeople.add (Newperson {"Lisa","Simpson", +}); Mypeople.add (Newperson {"Lilei","Simpson", -});//To modify the first value using an indexermypeople[0]=Newperson {"Zhangsan","Simpson", -} ;...

3. Index objects using string values

If you use the generic dictionary<tkey,tvalue> type directly, you can get the indexer method function without having to build it yourself.

 Public classpeoplecollection:ienumerable{Privatedictionary<string,person> listpeople=Newdictionary<string,person>(); //returns a person based on a string index        PublicPerson This[stringName] {             Get{return(person) listpeople[name];} Set{listpeople[name]=value;} } ...}

4. Overloaded Indexer Method

An indexer method can be overloaded on a single class or struct.

// datatablecollection type, overloaded indexer  Public  This [string name] {get;}  Public  This [string name,string tablenamespace] {get;}  Public  This [int index] {get;}

5, Multidimensional Indexer: The typical representative is the DataTable in ADO

Private int New int [ten];  Public int  This [int row,int  colum]{/*  take value or assignment from two-bit array */}

6. Define indexers on the interface type

In an interface-defined indexer, its implementation class can provide a custom implementation

 Public Interface istringcontainer{     // This interface defines an indexer that returns a string based on a numeric index .      [int index] {get;  Set;}}

C # Indexer Method