c#高级编程11,c#经典教程,c#入门经典教程,c#实战教程,c#基础教程,c#高级编程第12
C#高级教程是指进阶的C#编程知识和技能，包括面向对象编程、泛型编程、多线程编程、反射编程、LINQ等方面。以下是一些相关例子：

1. 面向对象编程：使用类和对象实现封装、继承和多态性，例如定义一个图形类Shape，派生出矩形类Rectangle和圆形类Circle，并重载虚函数计算面积。

csharp
public abstract class Shape
{
public abstract double Area();
}

public class Rectangle : Shape
{
private double length;
private double width;

public Rectangle(double len, double wid)
{
length = len;
width = wid;
}

public override double Area()
{
return length * width;
}
}

public class Circle : Shape
{
private double radius;

public Circle(double r)
{
radius = r;
}

public override double Area()
{
return Math.PI * radius * radius;
}
}


2. 泛型编程：使用泛型类和方法提高代码的复用性和类型安全性，例如实现一个堆栈类Stack<T>，支持Push、Pop和Peek操作。

csharp
public class Stack<T>
{
private List<T> data = new List<T>();

public void Push(T item)
{
data.Add(item);
}

public T Pop()
{
if (data.Count == 0)
{
throw new InvalidOperationException("Stack is empty");
}
T item = data[data.Count - 1];
data.RemoveAt(data.Count - 1);
return item;
}

public T Peek()
{
if (data.Count == 0)
{
throw new InvalidOperationException("Stack is empty");
}
return data[data.Count - 1];
}
}


3. 多线程编程：使用线程和任务管理并发执行的代码，例如在主线程中创建后台任务，更新UI界面。

csharp
private async void button_Click(object sender, EventArgs e)
{
string url = textBoxUrl.Text;
Task<string> downloadTask = Task.Run(() => DownloadPageAsync(url));
labelStatus.Text = "Downloading...";
string html = await downloadTask;
webBrowser.DocumentText = html;
labelStatus.Text = "Done.";
}

private async Task<string> DownloadPageAsync(string url)
{
using (HttpClient client = new HttpClient())
{
HttpResponseMessage response = await client.GetAsync(url);
response.EnsureSuccessStatusCode();
string html = await response.Content.ReadAsStringAsync();
return html;
}
}


4. 反射编程：使用反射API获取类型信息、调用成员和生成实例，例如通过类名创建对象并访问属性和方法。

csharp
Type type = Type.GetType("System.Diagnostics.Process");
object process = Activator.CreateInstance(type);
type.GetProperty("StartInfo").SetValue(process, new ProcessStartInfo("notepad.exe"));
type.GetMethod("Start").Invoke(process, null);


5. LINQ：使用查询表达式或方法链查询数据集合，例如从学生列表中筛选成绩优秀的学生和计算平均分。

csharp
List<Student> students = GetStudents();
var query = from student in students
where student.Score >= 90
orderby student.Score descending
select student;
double average = students.Average(student => student.Score);