C#获取文件(磁盘驱动器)的关联图标、获取目录文件和图标

我就是我 2022-06-01 02:19 466阅读 0赞

我们知道在VC++环境下利用Extended Combobox很容易实现下图的样子，但是在Vc\#条件下没有可扩展的Combobox控件，所以在实现起来比较麻烦。这里笔者向大家推荐两个类，第一个类用来获取本地的文件、文件夹、磁盘图标，第二类用来在Combobox中显示图标。

虽然这两个用法都比较简单，但是在实现起来还是破费周折的。

[![C\#获取文件(磁盘驱动器)的关联图标、获取目录文件和图标（原创）][C]][C_C]

一、获取文件、文件夹、本地磁盘的类GetIcon

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Runtime.InteropServices;
    using System.Drawing;
    
    namespace Gateway
    {
        public class GetIcon
        {
            [DllImport("Shell32.dll")]
            private static extern IntPtr SHGetFileInfo
            (
                string pszPath,
                uint dwFileAttributes,
                out   SHFILEINFO psfi,
                uint cbfileInfo,
                SHGFI uFlags
            );
      
    
            [StructLayout(LayoutKind.Sequential)]
            private struct SHFILEINFO
            {
                public SHFILEINFO(bool b)
                {
                    hIcon = IntPtr.Zero; iIcon = 0; dwAttributes = 0; szDisplayName = ""; szTypeName = "";
                }
                public IntPtr hIcon;
                public int iIcon;
                public uint dwAttributes;
                [MarshalAs(UnmanagedType.LPStr, SizeConst = 260)]
                public string szDisplayName;
                [MarshalAs(UnmanagedType.LPStr, SizeConst = 80)]
                public string szTypeName;
            };
    
         
    
            private enum SHGFI
            {
                SmallIcon = 0x00000001,
                LargeIcon = 0x00000000,
                Icon = 0x00000100,
                DisplayName = 0x00000200,
                Typename = 0x00000400,
                SysIconIndex = 0x00004000,
                UseFileAttributes = 0x00000010
            }
    
            /// <summary>
            /// 根据文件扩展名得到系统扩展名的图标
            /// </summary>
            /// <param name="fileName">文件名(如：win.rar;setup.exe;temp.txt)</param>
            /// <param name="largeIcon">图标的大小</param>
            /// <returns></returns>
            public static Icon GetFileIcon(string fileName, bool largeIcon)
            {
                SHFILEINFO info = new SHFILEINFO(true);
                int cbFileInfo = Marshal.SizeOf(info);
                SHGFI flags;
                if (largeIcon)
                    flags = SHGFI.Icon | SHGFI.LargeIcon | SHGFI.UseFileAttributes;
                else
                    flags = SHGFI.Icon | SHGFI.SmallIcon | SHGFI.UseFileAttributes;
                IntPtr IconIntPtr=SHGetFileInfo(fileName, 256, out info, (uint)cbFileInfo, flags);
                if (IconIntPtr.Equals(IntPtr.Zero))
                    return null;
                return Icon.FromHandle(info.hIcon);
            }
    
            /// <summary>  
            /// 获取文件夹图标
            /// </summary>  
            /// <returns>图标</returns>  
            public static Icon GetDirectoryIcon(bool largeIcon)
            {
                SHFILEINFO _SHFILEINFO = new SHFILEINFO();
                int cbFileInfo = Marshal.SizeOf(_SHFILEINFO);
                SHGFI flags;
                if (largeIcon)
                    flags = SHGFI.Icon | SHGFI.LargeIcon;
                else
                    flags = SHGFI.Icon | SHGFI.SmallIcon;
    
                IntPtr IconIntPtr = SHGetFileInfo(@"", 0, out _SHFILEINFO, (uint)cbFileInfo, flags);
                if (IconIntPtr.Equals(IntPtr.Zero))
                    return null;
                Icon _Icon = System.Drawing.Icon.FromHandle(_SHFILEINFO.hIcon);
                return _Icon;
            } 
    
        }
    }

二、扩展Combobox控件的类ComboBoxEx

using System;
    using System.Collections.Generic;
    using System.ComponentModel;
    using System.Data;
    using System.Drawing;
    using System.Linq;
    using System.Text;
    using System.Windows.Forms;
    
    namespace Gateway
    {
            class ComboBoxEx : ComboBox
            {
                private ImageList imageList;
                public ImageList ImageList
                {
                    get { return imageList; }
                    set { imageList = value; }
                }
    
                public ComboBoxEx()
                {
                    DrawMode = DrawMode.OwnerDrawFixed;
                }
    
                protected override void OnDrawItem(DrawItemEventArgs ea)
                {
                    ea.DrawBackground();
                    ea.DrawFocusRectangle();
    
                    ComboBoxExItem item;
                    Size imageSize = imageList.ImageSize;
                    Rectangle bounds = ea.Bounds;
    
                    try
                    {
                        item = (ComboBoxExItem)Items[ea.Index];
    
                        if (item.ImageIndex != -1)
                        {
                            imageList.Draw(ea.Graphics, bounds.Left, bounds.Top,
                            item.ImageIndex);
                            ea.Graphics.DrawString(item.Text, ea.Font, new
                            SolidBrush(ea.ForeColor), bounds.Left + imageSize.Width, bounds.Top);
                        }
                        else
                        {
                            ea.Graphics.DrawString(item.Text, ea.Font, new
                            SolidBrush(ea.ForeColor), bounds.Left, bounds.Top);
                        }
                    }
                    catch
                    {
                        if (ea.Index != -1)
                        {
                            ea.Graphics.DrawString(Items[ea.Index].ToString(), ea.Font, new
                            SolidBrush(ea.ForeColor), bounds.Left, bounds.Top);
                        }
                        else
                        {
                            ea.Graphics.DrawString(Text, ea.Font, new
                            SolidBrush(ea.ForeColor), bounds.Left, bounds.Top);
                        }
                    }
    
                    base.OnDrawItem(ea);
                }
            }
    
            class ComboBoxExItem
            {
                private string _text;
                public string Text
                {
                    get { return _text; }
                    set { _text = value; }
                }
    
                private int _imageIndex;
                public int ImageIndex
                {
                    get { return _imageIndex; }
                    set { _imageIndex = value; }
                }
    
                public ComboBoxExItem()
                    : this("")
                {
                }
    
                public ComboBoxExItem(string text)
                    : this(text, -1)
                {
                }
    
                public ComboBoxExItem(string text, int imageIndex)
                {
                    _text = text;
                    _imageIndex = imageIndex;
                }
    
                public override string ToString()
                {
                    return _text;
                }
            }
    }

[C]: http://s8.sinaimg.cn/bmiddle/63a9d0884b139bb151607&690
[C_C]: /images/20220601/7ae2356ed92c405ea27006ea70e0fd82.png