C#入门11.4——预定义异常类（1）

异常类 说明 

Exception 所有异常对象的基类

SystemException 运行时产生的所有错误的基类

IndexOutOfRangeException 当一个数组的下标超出范围时运行时引发

NullReferenceException 当一个空对象被引用时运行时引发 

ArgumentException 所有参数异常的基类

using System;
using System.Collections.Generic;

public class MyClass
{
  public static void RunSnippet()
  {
    int[] myint = { 1,2,3,4,5,6,7,8,9,0};
    try
    {
      for(int i=0;i<11;i++)
      Console.WriteLine(myint[i]);
    }
    catch(IndexOutOfRangeException exIOR)
    {
      Console.WriteLine(exIOR.Message.ToString());
    }
  }
  
}

索引超出了数组界限。

using System;
using System.Collections.Generic;
    
public class MyClass
{
  public static void RunSnippet()
  {
  <span style="white-space:pre">  </span>string mystr=null;
  <span style="white-space:pre">  </span>try
<span style="white-space:pre">  </span>  {

<span style="white-space:pre">  </span>    Console.WriteLine(mystr.ToString());

}
    catch (NullReferenceException ex)
    {
      Console.WriteLine(ex.Message.ToString());
    }
    
  }

}

using System;
using System.Collections.Generic;

public class MyClass
{
  static int DivideByTwo(int num)
  {
    if(num%2==1)throw new ArgumentException("此处必须为偶数","num");
      return num/2;
  }
  public static void RunSnippet()
  {
    try
    {
      Console.WriteLine(DivideByTwo(9));
    }
      catch(ArgumenException)
      {
        Console.WriteLine("9不能被2整除");
      }
    }
  }
  
}