日期:2011-04-25 浏览次数:20545 次
在C#中使用一个类时,分两个阶段。首先需要定义这个类,即告诉编译器这个类由什么字段和方法组成。然后(除非只使用静态方法)实例化类的一个对象。使用委托时,也需要经过这两个步骤。首先定义要使用的委托,对于委托,定义它就是告诉编译器这种类型代表了那种类型的方法,然后创建该委托的一个或多个实例。 using System; namespace Wrox.ProfCSharp.AdvancedCSharp class MainEntryPoint for (int i=0 ; i<employees.Length ; i++) class Employee // : object public Employee(string name, decimal salary) public override string ToString() public static bool RhsIsGreater(object lhs, object rhs) class BubbleSorter
定义委托是从delegate开始的然而它是如何运作的呢。也许弄个鼠标事件会容易理解一些,这里还是拿出书中的例子来。
{
delegate bool CompareOp(object lhs, object rhs);
{
static void Main()
{
Employee [] employees =
{
new Employee("Karli Watson", 20000),
new Employee("Bill Gates", 10000),
new Employee("Simon Robinson", 25000),
new Employee("Mortimer", (decimal)1000000.38),
new Employee("Arabel Jones", 23000),
new Employee("Avon from 'Blake's 7'", 50000)};
CompareOp employeeCompareOp = new CompareOp(Employee.RhsIsGreater);
BubbleSorter.Sort(employees, employeeCompareOp);
Console.WriteLine(employees[i].ToString());
Console.ReadLine();
}
}
{
private string name;
private decimal salary;
{
this.name = name;
this.salary = salary;
}
{
return string.Format(name + ", {0:C}", salary);
}
{
Employee empLhs = (Employee) lhs;
Employee empRhs = (Employee) rhs;
return (empRhs.salary > empLhs.salary) ? true : false;
}
}
{
static public void Sort(object [] sortArray, CompareOp gtMethod)
{
for (int i=0 ; i<sortArray.Length ; i++)
{
for (int j=i+1 ; j<sortArray.Length ; j++)
{
if (gtMethod(sortArray[j], sortArray[i]))
&nb