说明：本例将目录中的文件显示在窗体的ListView控件中，并定义了多种视图浏览。通过调用Win32库函数实现图标数据的提取。
主程序：
大图标：
列表：
详细信息：
Form1.cs：
public partial class Form1 : Form
{
FileInfoList fileList;
public Form1()
{
InitializeComponent();
}
private void 加载文件ToolStripMenuItem_Click(object sender, EventArgs e)
{
FolderBrowserDialog dlg = new FolderBrowserDialog();
if (dlg.ShowDialog() == DialogResult.OK)
{
string[] filespath = Directory.GetFiles(dlg.SelectedPath);
fileList = new FileInfoList(filespath);
InitListView();
}
}
private void InitListView()
{
listView1.Items.Clear();
this.listView1.BeginUpdate();
foreach (FileInfoWithIcon file in fileList.list)
{
ListViewItem item = new ListViewItem();
item.Text = file.fileInfo.Name.Split('.')[0];
item.ImageIndex = file.iconIndex;
item.SubItems.Add(file.fileInfo.LastWriteTime.ToString());
item.SubItems.Add(file.fileInfo.Extension.Replace(".",""));
item.SubItems.Add(string.Format(("{0:N0}"), file.fileInfo.Length));
listView1.Items.Add(item);
}
listView1.LargeImageList = fileList.imageListLargeIcon;
listView1.SmallImageList = fileList.imageListSmallIcon;
listView1.Show();
this.listView1.EndUpdate();
}
private void 大图标ToolStripMenuItem_Click(object sender, EventArgs e)
{
listView1.View = View.LargeIcon;
}
private void 小图标ToolStripMenuItem_Click(object sender, EventArgs e)
{
listView1.View = View.SmallIcon;
}
private void 平铺ToolStripMenuItem_Click(object sender, EventArgs e)
{
listView1.View = View.Tile;
}
private void 列表ToolStripMenuItem_Click(object sender, EventArgs e)
{
listView1.View = View.List;
}
private void 详细信息ToolStripMenuItem_Click(object sender, EventArgs e)
{
listView1.View = View.Details;
}
}
FileInfoList.cs：
说明：主要用于后台数据的存储
class FileInfoList
{
public List<FileInfoWithIcon> list;
public ImageList imageListLargeIcon;
public ImageList imageListSmallIcon;
/// <summary>
/// 根据文件路径获取生成文件信息，并提取文件的图标
/// </summary>
/// <param name="filespath"></param>
public FileInfoList(string[] filespath)
{
list = new List<FileInfoWithIcon>();
imageListLargeIcon = new ImageList();
imageListLargeIcon.ImageSize = new Size(32, 32);
imageListSmallIcon = new ImageList();
imageListSmallIcon.ImageSize = new Size(16, 16);
foreach (string path in filespath)
{
FileInfoWithIcon file = new FileInfoWithIcon(path);
imageListLargeIcon.Images.Add(file.largeIcon);
imageListSmallIcon.Images.Add(file.smallIcon);
file.iconIndex = imageListLargeIcon.Images.Count - 1;
list.Add(file);
}
}
}
class FileInfoWithIcon
{
public FileInfo fileInfo;
public Icon largeIcon;
public Icon smallIcon;
public int iconIndex;
public FileInfoWithIcon(string path)
{
fileInfo = new FileInfo(path);
largeIcon = GetSystemIcon.GetIconByFileName(path, true);
if (largeIcon == null)
largeIcon = GetSystemIcon.GetIconByFileType(Path.GetExtension(path), true);
smallIcon = GetSystemIcon.GetIconByFileName(path, false);
if (smallIcon == null)
smallIcon = GetSystemIcon.GetIconByFileType(Path.GetExtension(path), false);
}
}
GetSystemIcon：
说明：定义两种图标获取方式，从文件提取和从文件关联的系统资源中提取。
public static class GetSystemIcon
{
/// <summary>
/// 依据文件名读取图标，若指定文件不存在，则返回空值。
/// </summary>
/// <param name="fileName">文件路径</param>
/// <param name="isLarge">是否返回大图标</param>
/// <returns></returns>
public static Icon GetIconByFileName(string fileName, bool isLarge = true)
{
int[] phiconLarge = new int[1];
int[] phiconSmall = new int[1];
//文件名 图标索引
Win32.ExtractIconEx(fileName, 0, phiconLarge, phiconSmall, 1);
IntPtr IconHnd = new IntPtr(isLarge ? phiconLarge[0] : phiconSmall[0]);
if (IconHnd.ToString() == "0")
return null;
return Icon.FromHandle(IconHnd);
}
/// <summary>
/// 根据文件扩展名（如:.*），返回与之关联的图标。
/// 若不以"."开头则返回文件夹的图标。
/// </summary>
/// <param name="fileType">文件扩展名</param>
/// <param name="isLarge">是否返回大图标</param>
/// <returns></returns>
public static Icon GetIconByFileType(string fileType, bool isLarge)
{
if (fileType == null || fileType.Equals(string.Empty)) return null;
RegistryKey regVersion = null;
string regFileType = null;
string regIconString = null;
string systemDirectory = Environment.SystemDirectory + "\\";
if (fileType[0] == '.')
{
//读系统注册表中文件类型信息
regVersion = Registry.ClassesRoot.OpenSubKey(fileType, false);
if (regVersion != null)
{
regFileType = regVersion.GetValue("") as string;
regVersion.Close();
regVersion = Registry.ClassesRoot.OpenSubKey(regFileType + @"\DefaultIcon", false);
if (regVersion != null)
{
regIconString = regVersion.GetValue("") as string;
regVersion.Close();
}
}
if (regIconString == null)
{
//没有读取到文件类型注册信息，指定为未知文件类型的图标
regIconString = systemDirectory + "shell32.dll,0";
}
}
else
{
//直接指定为文件夹图标
regIconString = systemDirectory + "shell32.dll,3";
}
string[] fileIcon = regIconString.Split(new char[] { ',' });
if (fileIcon.Length != 2)
{
//系统注册表中注册的标图不能直接提取，则返回可执行文件的通用图标
fileIcon = new string[] { systemDirectory + "shell32.dll", "2" };
}
Icon resultIcon = null;
try
{
//调用API方法读取图标
int[] phiconLarge = new int[1];
int[] phiconSmall = new int[1];
uint count = Win32.ExtractIconEx(fileIcon[0], Int32.Parse(fileIcon[1]), phiconLarge, phiconSmall, 1);
IntPtr IconHnd = new IntPtr(isLarge ? phiconLarge[0] : phiconSmall[0]);
resultIcon = Icon.FromHandle(IconHnd);
}
catch { }
return resultIcon;
}
}
/// <summary>
/// 定义调用的API方法
/// </summary>
class Win32
{
[DllImport("shell32.dll")]
public static extern uint ExtractIconEx(string lpszFile, int nIconIndex, int[] phiconLarge, int[] phiconSmall, uint nIcons);
}
纸上得来终觉浅,绝知此事要躬行。
