代码改变世界

U盘加载,卸载,拔出,插入,WM_DEVICECHANGE,WndProc,DBT_DEVICEARRIVAL,DBT_DEVICEREMOVECOMPLETE

2008-08-22 14:42  Virus-BeautyCode  阅读(19496)  评论(5编辑  收藏  举报

最近在做一个和U盘有关的项目,有一个需求是要求显示插入的U盘的盘符,当然了,如果拔出U盘,也应该更新显示,就是显示U口上插入的全部移动设备的全部盘符。

其实就是重写
protected override void WndProc(ref Message m)

方法,根据得到的系统消息来处理,但是如果要实时更新的话,最好加上定时查询U口设备,将查询结果更新,时间的间隔可以自己定义,根据项目情况吧。
下面是完整的代码,如果大家有什么好的建议,欢迎大家一起交流。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.IO;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApp
{
    
public partial class ComboBoxForm2 : Form
    {
        
private IList<string> diskList = new List<string>();

        
delegate void SetTextCallback(string s);
        
delegate void ClearListBoxItem();

        
private Thread thread = null;
        
private BackgroundWorker backgroundworker;

        
public ComboBoxForm2()
        {
            InitializeComponent();
        }

        
protected override void WndProc(ref Message m)
        {
            
object ojb = new object();
            
try
            {
                
//WM_DEVICECHANGE,系统硬件改变发出的系统消息
                if (m.Msg == WndProMsgConst.WM_DEVICECHANGE)
                {
                    
switch (m.WParam.ToInt32())
                    {
                        
case WndProMsgConst.WM_DEVICECHANGE:
                            
break;
                        
//DBT_DEVICEARRIVAL,设备检测结束,并且可以使用
                        case WndProMsgConst.DBT_DEVICEARRIVAL:
                            scanUDisk();
                            listBox1.Items.Clear();
                           
foreach (string s in diskList)
            {
                listBox1.Items.Add(s);
            }
                            
break;
                        
//DBT_DEVICEREMOVECOMPLETE,设备卸载或者拔出
                        case WndProMsgConst.DBT_DEVICEREMOVECOMPLETE:
                            scanUDisk();
                            listBox1.Items.Clear();
                            
foreach (string s in diskList)
                            {
                                listBox1.Items.Add(s);
                            }
                            
break;
                       
                    }
                }
            }
            
catch (Exception ex)
            {
                MessageBox.Show(
"当前盘不能正确识别,请重新尝试!""提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
            
base.WndProc(ref m);
        }
        
private void button1_Click(object sender, EventArgs e)
        {
            IList
<string> diskList = new List<string>();
            diskList.Add(
"k001");
            diskList.Add(
"k002");
            diskList.Add(
"k003");
            diskList.Add(
"k004");
            comboBox1.DataSource 
= diskList;
        }
        
/// <summary>
        
/// 扫描U口设备
        
/// </summary>
        
/// <param name="obj"></param>
        private void scanUDisk()
        {
            diskList.Clear();
            DriveInfo[] drives 
= DriveInfo.GetDrives();

            
foreach (DriveInfo drive in drives)
            {
                
if ((drive.DriveType == DriveType.Removable) && !drive.Name.Substring(01).Equals("A"))
                {
                    
try
                    {
                        diskList.Add(drive.Name);
                    }
                    
catch
                    {
                        MessageBox.Show(
"当前盘不能正确识别,请重新尝试!""提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }

                }
            }
        }
        
private void ComboBoxForm2_Load(object sender, EventArgs e)
        {
            System.Timers.Timer timer 
= new System.Timers.Timer(1000);
            timer.Enabled 
= true;
            timer.Elapsed 
+= new System.Timers.ElapsedEventHandler(fi);
            timer.AutoReset 
= true;

            
        }
       
        
private void ThreadProcSafe()
        {

            scanUDisk();
            
//MessageBox.Show(diskList.Count.ToString());

            
foreach (string s in diskList)
            {
                SetText(s);
            }
        }
        
public void SetText(string text)
        {
            
if (this.listBox1.InvokeRequired)
            {
                
if (listBox1.Items.Contains(text))
                    
return;
                SetTextCallback d 
= new SetTextCallback(SetText);
                
this.Invoke(d, new object[] { text });
            }
            
else
            {
                
if (listBox1.Items.Contains(text))
                    
return;
                
this.listBox1.Items.Add(text);
            }
        }
        
void fi(object sender, System.Timers.ElapsedEventArgs e)
        {
            scanUDisk();
            
//listBox1.Items.Clear();
            foreach (string s in diskList)
            {
                SetText(s);
            }
        }
    }
    
/// <summary>
    
/// windows消息的常量
    
/// </summary>
    class WndProMsgConst
    {
        
#region WndProc常量
        
public const int WM_DEVICECHANGE = 0x219;
        
public const int DBT_DEVICEARRIVAL = 0x8000;
        
public const int DBT_CONFIGCHANGECANCELED = 0x0019;
        
public const int DBT_CONFIGCHANGED = 0x0018;
        
public const int DBT_CUSTOMEVENT = 0x8006;
        
public const int DBT_DEVICEQUERYREMOVE = 0x8001;
        
public const int DBT_DEVICEQUERYREMOVEFAILED = 0x8002;
        
public const int DBT_DEVICEREMOVECOMPLETE = 0x8004;
        
public const int DBT_DEVICEREMOVEPENDING = 0x8003;
        
public const int DBT_DEVICETYPESPECIFIC = 0x8005;
        
public const int DBT_DEVNODES_CHANGED = 0x0007;
        
public const int DBT_QUERYCHANGECONFIG = 0x0017;
        
public const int DBT_USERDEFINED = 0xFFFF;
        
#endregion
    }
}


设备的实时性还是差一点,还有啊,像这样的窗体有很多,我不能每个窗体都copy一遍这些代码吧,如何封装起来呢,控件的线程安全也是问题,还需要改进啊,谁有好的意见可以提出来。

msn:jorden008@hotmail.com
mail:jorden008@163.com


简单封装了一下,封装类如下:

using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Threading;
using System.IO;

namespace WindowsApp
{
    
class Class1
    {
        
private IList<string> diskList = new List<string>();

        
delegate void SetTextCallback(string s);
        
delegate void ClearListBoxItem();
        
private ListBox _listbox;
        
private Form _form;
        
private Thread thread = null;
        
//private BackgroundWorker backgroundworker;

        
public Class1()
        {

            System.Timers.Timer timer 
= new System.Timers.Timer(1000);
            timer.Enabled 
= true;
            timer.Elapsed 
+= new System.Timers.ElapsedEventHandler(fi);
            timer.AutoReset 
= true;
        }
        
public void filldata(Form form, Message m,ListBox listbox)
        {
            _listbox 
= listbox;
            _form 
= form;
            
try
            {
                
//WM_DEVICECHANGE,系统硬件改变发出的系统消息
                if (m.Msg == WndProMsgConst.WM_DEVICECHANGE)
                {
                    
switch (m.WParam.ToInt32())
                    {
                        
case WndProMsgConst.WM_DEVICECHANGE:
                            
break;
                        
//DBT_DEVICEARRIVAL,设备检测结束,并且可以使用
                        case WndProMsgConst.DBT_DEVICEARRIVAL:
                            scanUDisk();
                            _listbox.Items.Clear();
                            
foreach (string s in diskList)
                            {
                                _listbox.Items.Add(s);
                            }
                            
break;
                        
//DBT_DEVICEREMOVECOMPLETE,设备卸载或者拔出
                        case WndProMsgConst.DBT_DEVICEREMOVECOMPLETE:
                            scanUDisk();
                            _listbox.Items.Clear();
                            
foreach (string s in diskList)
                            {
                                _listbox.Items.Add(s);
                            }
                            
break;

                    }
                }
            }
            
catch (Exception ex)
            {
                MessageBox.Show(
"当前盘不能正确识别,请重新尝试!""提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }
        }
        
public void SetText(string text)
        {
            
if (this._listbox.InvokeRequired)
            {
                
if (_listbox.Items.Contains(text))
                    
return;
                SetTextCallback d 
= new SetTextCallback(SetText);
                _form.Invoke(d, 
new object[] { text });
            }
            
else
            {
                
if (_listbox.Items.Contains(text))
                    
return;
                
this._listbox.Items.Add(text);
            }
        }
        
void fi(object sender, System.Timers.ElapsedEventArgs e)
        {
            scanUDisk();
            
//listBox1.Items.Clear();
            foreach (string s in diskList)
            {
                SetText(s);
            }
        }
/// <summary>
        
/// 扫描U口设备
        
/// </summary>
        
/// <param name="obj"></param>
        private void scanUDisk()
        {
            diskList.Clear();
            DriveInfo[] drives 
= DriveInfo.GetDrives();

            
foreach (DriveInfo drive in drives)
            {
                
if ((drive.DriveType == DriveType.Removable) && !drive.Name.Substring(01).Equals("A"))
                {
                    
try
                    {
                        diskList.Add(drive.Name);
                    }
                    
catch
                    {
                        MessageBox.Show(
"当前盘不能正确识别,请重新尝试!""提示", MessageBoxButtons.OK, MessageBoxIcon.Information);
                    }

                }
            }
        }
    } 
/// <summary>
    
/// windows消息的常量
    
/// </summary>
    class WndProMsgConst
    {
        
#region WndProc常量
        
public const int WM_DEVICECHANGE = 0x219;
        
public const int DBT_DEVICEARRIVAL = 0x8000;
        
public const int DBT_CONFIGCHANGECANCELED = 0x0019;
        
public const int DBT_CONFIGCHANGED = 0x0018;
        
public const int DBT_CUSTOMEVENT = 0x8006;
        
public const int DBT_DEVICEQUERYREMOVE = 0x8001;
        
public const int DBT_DEVICEQUERYREMOVEFAILED = 0x8002;
        
public const int DBT_DEVICEREMOVECOMPLETE = 0x8004;
        
public const int DBT_DEVICEREMOVEPENDING = 0x8003;
        
public const int DBT_DEVICETYPESPECIFIC = 0x8005;
        
public const int DBT_DEVNODES_CHANGED = 0x0007;
        
public const int DBT_QUERYCHANGECONFIG = 0x0017;
        
public const int DBT_USERDEFINED = 0xFFFF;
        
#endregion
    }
}


使用方法如下:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.IO;
using System.Windows.Forms;
using System.Threading;

namespace WindowsApp
{
    
public partial class ComboBoxForm2 : Form
    {
        
public ComboBoxForm2()
        {
            InitializeComponent();
        }

        
protected override void WndProc(ref Message m)
        {
            Class1 c
=new Class1();
            c.filldata(
this,m, listBox1);
            
            
base.WndProc(ref m);
        }
       
    }
   
}