Introduction
In this small example I used Directory.GetLogicalDrives() method to retieve the names of all logical drives.
Than I used GetDriveType(string driveLetter) method from kernel32.dll to get types of those drives (CDROM,FLOPPY,Local Disc etc.) so I knew what
icon should be displayed next to the drive name.
The Drive names (Volume Labels) I got using GetVolumeInformation method from the same DLL as before.
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Runtime.InteropServices;
using System.IO;
using System.Text;
struct DriveInfo
{
private string letter;
private int type;
private string name;
public int Type
{
get
{
return type;
}
}
public int Icon
{
get
{
if(name=="My Computer")return 0;
if(type==5)return 3;
if(type==3)return 2;
if(type==2)return 1;
if(type==4)return 4;
if(type==6)return 5;
return 6;
}
}
public string Letter
{
get
{
if(letter!="")return " ("+letter+")";
else return "";
}
}
public string Name
{
get
{
if(name!="")return name;
else{
switch (this.Type)
{
case 3:
if(letter==System.IO.Directory.GetDirectoryRoot(
System.Environment.SystemDirectory))
return "System";
else
return "Local Disc";
case 5:return "CD Rom";
case 6:return "RAM Disc";
case 4:return "Network Drive";
case 2:
if(letter=="A:\\")return "3.5 Floppy";
else return "Removable Disc";
default:return "";
}
}
}
}
//TYPE:
//5-A CD-ROM drive.
//3-A hard drive.
//6-A RAM disk.
//4-A network drive or a drive located on a network server.
//2-A floppy drive or some other removable-disk drive.
public DriveInfo(string strLetter,int intType,string strName)
{
letter=strLetter;
name=strName;
type=intType;
}
}
namespace ComboBox2
{
/// <summary>
/// Summary description for Form1.
/// </summary>
public class Form1 : System.Windows.Forms.Form
{
private System.Windows.Forms.ComboBox comboBox1;
private System.ComponentModel.IContainer components;
private System.Windows.Forms.ImageList imageList1;
private System.Windows.Forms.Label label1;
private ArrayList availableDrives = new ArrayList();
[DllImport("kernel32.dll")]
public static extern long GetDriveType(string driveLetter);
[DllImport("kernel32.dll")]
public static extern long GetVolumeInformation(string strPathName,
StringBuilder strVolumeNameBuffer,
long lngVolumeNameSize,
long lngVolumeSerialNumber,
long lngMaximumComponentLength,
long lngFileSystemFlags,
StringBuilder strFileSystemNameBuffer,
long lngFileSystemNameSize);
public Form1()
{
//
// Required for Windows Form Designer support
//
InitializeComponent();
//
// TODO: Add any constructor code after InitializeComponent call
//
findLogicalDrives();
initDriveCombo();
}
/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
}
base.Dispose( disposing );
}
#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.components = new System.ComponentModel.Container();
System.Resources.ResourceManager resources
= new System.Resources.ResourceManager(typeof(Form1));
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.imageList1 = new System.Windows.Forms.ImageList(this.components);
this.label1 = new System.Windows.Forms.Label();
this.SuspendLayout();
//
// comboBox1
//
this.comboBox1.BackColor = System.Drawing.SystemColors.Window;
this.comboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed;
this.comboBox1.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
this.comboBox1.DropDownWidth = 200;
this.comboBox1.ForeColor = System.Drawing.SystemColors.WindowText;
this.comboBox1.ItemHeight = 16;
this.comboBox1.Location = new System.Drawing.Point(48, 40);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(200, 22);
this.comboBox1.TabIndex = 0;
this.comboBox1.DrawItem +=
new System.Windows.Forms.DrawItemEventHandler(this.OnComboDrawItem);
//
// imageList1
//
this.imageList1.ColorDepth = System.Windows.Forms.ColorDepth.Depth32Bit;
this.imageList1.ImageSize = new System.Drawing.Size(16, 16);
this.imageList1.ImageStream = ((System.Windows.Forms.ImageListStreamer)
(resources.GetObject("imageList1.ImageStream")));
this.imageList1.TransparentColor = System.Drawing.Color.Transparent;
//
// label1
//
this.label1.Font = new System.Drawing.Font("Microsoft Sans Serif",
9.75F,
System.Drawing.FontStyle.Regular,
System.Drawing.GraphicsUnit.Point,
((System.Byte)(0)));
this.label1.Location = new System.Drawing.Point(8, 40);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(40, 16);
this.label1.TabIndex = 1;
this.label1.Text = "Drive:";
//
// Form1
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.label1,
this.comboBox1});
this.Icon = ((System.Drawing.Icon)(resources.GetObject("$this.Icon")));
this.Name = "Form1";
this.Text = "DriveComboBox";
this.ResumeLayout(false);
}
#endregion
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static void Main()
{
Application.Run(new Form1());
}
private void OnComboDrawItem(object sender, System.Windows.Forms.DrawItemEventArgs e)
{
Bitmap tempBitmap = new Bitmap(e.Bounds.Width,e.Bounds.Height,e.Graphics);
Graphics tempGraphics = Graphics.FromImage(tempBitmap);
//all items with offset, but MyComputer
int offset=0;if(e.Index == 0)offset = 0;else offset = 20;
//item in comboBoxEdit no space in front
if((e.State & DrawItemState.ComboBoxEdit)!=0)offset=0;
if(e.Index == -1)return;// ???????????
string tempLetter=((DriveInfo)availableDrives[e.Index]).Letter;
string tempName=((DriveInfo)availableDrives[e.Index]).Name;
string tempString = tempName+tempLetter;
int tempIcon = ((DriveInfo)availableDrives[e.Index]).Icon;
tempGraphics.FillRectangle(new SolidBrush(e.BackColor),
new Rectangle(0,0,tempBitmap.Width,tempBitmap.Height));
tempGraphics.DrawString(tempString,e.Font ,new SolidBrush(e.ForeColor),
new Point(28+offset,(tempBitmap.Height-e.Font.Height)/2));
tempGraphics.DrawImage(imageList1.Images[tempIcon],
new Rectangle(new Point(6+offset,0),new Size(16,16)));
e.Graphics.DrawImage(tempBitmap,e.Bounds.X,e.Bounds.Y);
}
public void findLogicalDrives()
{
string[] tempString = Directory.GetLogicalDrives();
DriveInfo tempInfo = new DriveInfo("",0,"My Computer");
availableDrives.Add(tempInfo);
foreach(string tempDrive in tempString)
{
int tempType = getDriveType(tempDrive);
string tempName = GetDriveName(tempDrive);
tempInfo = new DriveInfo(tempDrive,tempType,tempName);
availableDrives.Add(tempInfo);
}
}
public int getDriveType(string drive)
{
if((GetDriveType(drive) & 5)==5)return 5;//cd
if((GetDriveType(drive) & 3)==3)return 3;//fixed
if((GetDriveType(drive) & 2)==2)return 2;//removable
if((GetDriveType(drive) & 4)==4)return 4;//remote disk
if((GetDriveType(drive) & 6)==6)return 6;//ram disk
return 0;
}
public string GetDriveName(string drive)
{
//receives volume name of drive
StringBuilder volname = new StringBuilder(256);
//receives serial number of drive,not in case of network drive(win95/98)
long sn= new long();
long maxcomplen = new long();//receives maximum component length
long sysflags = new long();//receives file system flags
StringBuilder sysname = new StringBuilder(256);//receives the file system name
long retval= new long();//return value
retval = GetVolumeInformation(drive, volname, 256, sn, maxcomplen,
sysflags, sysname,256);
if(retval!=0)return volname.ToString();
else return "";
}
public void initDriveCombo()
{
foreach(DriveInfo tempDrvInfo in availableDrives)
{
comboBox1.Items.Add(tempDrvInfo.Letter);
}
comboBox1.SelectedIndex=0;
}
}
}
Comments, questions? odah@hotmail.com
