form1.cs

清华大学出版社出版的 移动应用开发宝典 张大威（2008）的附书源代码

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using CodeForChapter4cs_DLL;
using System.Diagnostics;
using System.IO;
using System.Collections;
using System.Reflection;

namespace CodeForChapter4cs
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
     // bool b;
      try
      {

      }
      catch (Exception)
      {
        //ex.StackTrace
        throw;
      }

      string s = "start";
      for (int i = 0; i < 30; i++)
      {
        s += "let's kill our perf";
      }

      this.ReturnSomething();
    }

    public int ReturnSomething()
    {
      return 5;
    }

    private void menuItem1_Click(object sender, EventArgs e)
    {
      //this.SomeMethod();
      this.AnotherMethod(new SomeClass());
    }

    private void SomeMethod()
    {
      // 1. let any exception bubble up
      this.MethodThatMayThrow();

      // 2. rethrow
      try
      {
        this.MethodThatMayThrow();
      }
      catch (Exception)
      {
        // do something with the exception object
        // or do something else as cleanup in this code block
        throw; //rethrows
      }

      // 3. Catch exception
      try
      {
        this.MethodThatMayThrow();
      }
      catch (Exception)
      {
        // FULLY deal with this exception
        //ex.st
      }
      
      // 4. Swallow
      try
      {
        this.MethodThatMayThrow();
      }
      catch (Exception)
      {
        // swallow, just so it doesn't go up to other methods
        // DO NOT do this!
      }
    }


    private void MethodThatMayThrow()
    {
      throw new Exception("The method or operation is not implemented.");
    }

    private void AnotherMethod(SomeClass obj)
    {
      try
      {
        ((ISomeInterface)obj).DoIt();
      }
      catch (InvalidCastException ex)
      {
        // log the exception to file
        Debug.WriteLine("The stacktrace: \r\n" + ex.StackTrace);
        // take some real recovery action!
      }
    }

    private void menuItem2_Click(object sender, EventArgs e)
    {
      SomeType obj = null;
      obj.SomeMethod();  // NullReferenceException
    }

    private void button1_Click(object sender, EventArgs e)
    {
      //this.DoSomethinginterestingWith(@"\testFile.txt");

      ArrayList ar=null;
      //ar.
      ar.Capacity = 1;
      this.WorkWithSomeList(ar);
    }

    private void DoSomethinginterestingWith(string path)
    {
      try
      {
        FileStream fs = File.Open(path, FileMode.Open); //FileNotFoundException
        // do something interesting with fs
      }
      catch (FileNotFoundException ex)
      {
        // TODO deal with the invalid input
      }
    }


    //private void DoSomethinginterestingWith(string path)
    //{
    //  if (File.Exists(path))
    //  {
    //    FileStream fs = File.Open(path, FileMode.Open); //FileNotFoundException
    //    // do something interesting with fs
    //  }
    //  else
    //  {
    //    // TODO deal with the invalid input
    //  }
    //}

    //private void AnotherMethod(SomeClass obj)
    //{
    //  ISomeInterface i = obj as ISomeInterface;
    //  if (i != null)
    //  {
    //    ((ISomeInterface)obj).DoIt();
    //  }
    //  else
    //  {
    //    // Do something else!
    //  }
    //}

    private void WorkWithSomeList(ArrayList ar)
    {
        ar.Add(new object());
      if (!(ar.IsFixedSize || ar.IsReadOnly))
      {        
      }
      else
      {
        // do some sensible alternative
      }

    }

    private void button2_Click(object sender, EventArgs e)
    {
      Type t = this.GetType();
      MethodInfo m = t.GetMethod("DoIt");
      m.Invoke(this, null);
    }

    public void DoIt()
    {
      throw new InvalidOperationException("my msg");
    }
  }

  public class SomeType
  {
    public void SomeMethod()
    {
    }
  }
}