c# - WPF C# 提取并显示默认文件图标

Question

我正在为某些扩展(例如 XLS、XLSX、PDF 等)提取系统默认图标(仅限 16 * 16)，并尝试在图像控制中显示该图标。我注意到，如果我将这些图标转储到磁盘上，它们看起来很清晰，但列表框中的图标看起来有些模糊。

你知道这里会发生什么吗？我从我读到的帖子中尝试了很多建议，但无法解决问题

代码片段:

案例1 - 我通过Win32 Pinvoke提取文件的图标 - 结果 -> 图标模糊

private const uint SHGFI_ICON = 0x100;
    private const uint SHGFI_LARGEICON = 0x0;
    private const uint SHGFI_SMALLICON = 0x1;
    private const int FILE_ATTRIBUTE_NORMAL = 0x80;
    private const uint SHGFI_USEFILEATTRIBUTES = 0x000000010;
    [StructLayout(LayoutKind.Sequential)]
    private struct SHFILEINFO
    {
        public IntPtr hIcon;
        public IntPtr iIcon;
        public uint dwAttributes;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
        public string szDisplayName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 80)]
        public string szTypeName;
    };
    [DllImport("shell32.dll")]
    private static extern IntPtr SHGetFileInfo(string pszPath, uint dwFileAttributes,   
   ref SHFILEINFO psfi, uint cbSizeFileInfo, uint uFlags);

private static Icon Extract(string fileName)
{
var shinfo = new SHFILEINFO();

IntPtr hIcon = SHGetFileInfo(fileName, 0, ref shinfo, (uint)Marshal.SizeOf(shinfo), SHGFI_ICON | SHGFI_SMALLICON);
//The icon is returned in the hIcon member of the shinfo struct
var icon = (Icon)Icon.FromHandle(shinfo.hIcon).Clone();
DestroyIcon(shinfo.hIcon);
return icon;
}
[DllImport("User32.dll")]
public static extern int DestroyIcon(IntPtr hIcon);

案例2 - 将上面创建的图标对象转储到磁盘并在资源管理器中查看它们 -> 图标质量非常好

string filePath = string.Format("C:\\temp\\Icons\\{0}.ico", iconName.Substring(1));
var stream = new FileStream(filePath, FileMode.OpenOrCreate);
iconObject.ExtensionSource.ToBitmap().Save(stream, ImageFormat.Bmp);
stream.Close();

列表框 xaml -

<Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <StackPanel Orientation="Horizontal"
                    Grid.Row="0"
                    Margin="10">
            <TextBox Text="{Binding ExtensionNames, Mode=TwoWay}"
                     ToolTip="Comma Separated List of Extensions, Tab out to persist changes.."
                     Margin="5"/>
            <Button Content="Dump All Icons" 
                    Click="Button_DumpAllIconsClick" 
                    Width="100"
                    ToolTip="Dump Path: C:\temp\Icons"
                    Margin="5"/>

        </StackPanel>
        <ListBox ItemsSource="{Binding Icons}"
                 Grid.Row="1"
                 Margin="2">
            <ListBox.ItemTemplate>
                <DataTemplate>
                    <StackPanel Orientation="Horizontal"
                                HorizontalAlignment="Stretch"
                                Margin="5">
                        <TextBlock Text="{Binding ExtensionName}"
                                       FontWeight="Bold"
                                       FontSize="20"/>
                        <Image Source="{Binding Path=ExtensionSource,
                                                Converter={ExtractIconWPF:IconToImageSourceConverter}}"
                               Margin="5"/>
                    </StackPanel>
                </DataTemplate>
            </ListBox.ItemTemplate>
            <ListBox.ItemContainerStyle>
                <Style TargetType="ListBoxItem">
                    <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
                </Style>
            </ListBox.ItemContainerStyle>
        </ListBox>
</Grid>

我如何将 Icon 转换为 ImageSource 对象:

var stream = GetIconStream(iconObject);
ImageSource source = GetBitMapImage(stream);

public static Stream GetIconStream(Icon icon)
{
var iconStream = new MemoryStream();

var bitmap = icon.ToBitmap();
bitmap.Save(iconStream, ImageFormat.Png);

return iconStream;
}

public static ImageSource GetBitMapImage(Stream iconStream)
{
var bi = new BitmapImage();

bi.BeginInit();
bi.StreamSource = iconStream;
bi.EndInit();

return bi;
}

任何指点都将受到高度赞赏!

谢谢

Answer 1

我知道这个问题已经有一段时间得到解决了，但我看到了一个很酷的 win32 调用快捷方式:

var sysicon = System.Drawing.Icon.ExtractAssociatedIcon(filePath);
var bmpSrc = System.Windows.Interop.Imaging.CreateBitmapSourceFromHIcon(
        sysicon.Handle,
        System.Windows.Int32Rect.Empty,
        System.Windows.Media.Imaging.BitmapSizeOptions.FromEmptyOptions());
sysicon.Dispose();

我认为这可能比你所做的一切更好。

来源:Here