в 15:31, 26 мая 2010

2010-05-26T15:31:53Z

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2010-05-26T12:14:46Z

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==Use an interface constraint==

<source lang="csharp">using System;

class NotFoundException : ApplicationException { }

public interface IUserID {
string Number {
get;
set;
}

string Name {
get;
set;
}
}

class Engineer : IUserID {
string name;
string number;

public Engineer(string n, string num) {
name = n;
number = num;
}

// Implement IUserID
public string Number {
get { return number; }
set { number = value; }
}

public string Name {
get { return name; }
set { name = value; }
}
}

class Manager : IUserID {
string name;
string number;

public Manager(string n, string num) {
name = n;
number = num;
}

// Implement IUserID
public string Number {
get { return number; }
set { number = value; }
}

public string Name {
get { return name; }
set { name = value; }
}
}

class Guest {

}

class IDList<T> where T : IUserID {
T[] idList;
int end;

public IDList() {
idList = new T[10];
end = 0;
}

public bool add(T newEntry) {
if(end == 10)
return false;

idList[end] = newEntry;
end++;

return true;
}

public T findByName(string name) {

for(int i=0; i<end; i++) {
if(idList[i].Name == name)
return idList[i];
}
throw new NotFoundException();
}

public T findByNumber(string number) {
for(int i=0; i<end; i++) {
if(idList[i].Number == number)
return idList[i];
}
throw new NotFoundException();
}
}

class MainClass {
public static void Main() {
IDList<Engineer> plist = new IDList<Engineer>();
plist.add(new Engineer("T", "1"));
plist.add(new Engineer("G", "6"));
plist.add(new Engineer("M", "9"));

try {
Engineer frnd = plist.findByName("G");
Console.Write(frnd.Name + ": " + frnd.Number);
} catch(NotFoundException) {
Console.WriteLine("Not Found");
}

Console.WriteLine();

IDList<Manager> plist2 = new IDList<Manager>();
plist2.add(new Manager("H", "8"));
plist2.add(new Manager("C", "2"));
plist2.add(new Manager("N", "4"));

try {
Manager sp = plist2.findByNumber("4");
Console.WriteLine(sp.Name + ": " + sp.Number);
} catch(NotFoundException) {
Console.WriteLine("Not Found");
}

// The following declaration is invalid
// because Guest does NOT implement IUserID.
// IDList<Guest> plist3 = new IDList<Guest>(); // Error!
}
}</source>
<pre class=codeResult>G: 6
N: 4</pre>

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в 15:31, 26 мая 2010

Admin: 1 версия