Question

我正在为某些扩展程序（如XLS，XLSX，PDF等）提取系统默认图标（仅限16 * 16）并尝试在Image Control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，但我的ListBox中的图标看起来有些模糊。

任何想法可能会发生在这里？我从我读过的帖子中尝试了很多建议，但是无法解决问题

代码段：

Case1 - 我通过Win32 Pinvoke提取文件图标 - 结果 - ＆gt;模糊的图标

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 - ＆gt;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();

ListBox 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;
}

任何指针都将受到高度赞赏！

由于

Answer 1

我知道已经有一段时间这个问题已经解决但我已经看到了win32调用的一个很酷的快捷方式：

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();

我认为它可能比你所做的更好。

来源：Here

Answer 2

以下是您问题的解决方案：

Get Registered File Types and Their Associated Icons in C#

由Man Vuong制作。

Answer 3

分享对我遇到类似问题的人有帮助的事情。

在Image上设置此属性有助于消除模糊：

RenderOptions.BitmapScalingMode="NearestNeighbor"

在其他情况下，我们在20 * 20的网格单元格中显示图像，因此我们最终删除了以下设置的默认图像拉伸。这也造成了很多不同。

Stretch = Stretch.None

WPF C＃提取并显示默认文件图标

3 个答案: