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Code Issues Releases Wiki Activity

Improved error handling and documentation

pull/10/head
David Hall 2018-01-22 18:23:01 -07:00
parent 8c030eb296
commit ce2db9f278
4 changed files with 195 additions and 99 deletions
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45
UnitTests/Shell/ShellItemTests.cs
View File

@ -66,10 +66,10 @@ namespace Vanara.Windows.Forms.Tests
}
[Test]
public void GetAttrTest()
{
Assert.That(() =>
{
public void GetAttrTest()
{
Assert.That(() =>
{
using (var i = new ShellItem(testDoc))
{
Assert.That(i.Attributes, Is.Not.Zero);
@ -84,7 +84,7 @@ namespace Vanara.Windows.Forms.Tests
Assert.That(i.ToolTipText, Is.Not.Null);
}
}, Throws.Nothing);
}
}
[Test]
public void GetDisplayNameTest()
@ -137,6 +137,16 @@ namespace Vanara.Windows.Forms.Tests
Assert.That(i.Properties[PROPERTYKEY.System.Author], Has.Member("TestAuthor"));
Assert.That(i.Properties[PROPERTYKEY.System.ItemTypeText], Does.StartWith("Microsoft Word"));
Assert.That(i.Properties[PROPERTYKEY.System.DateAccessed], Is.TypeOf<FILETIME>());
Assert.That(() => i.Properties[new PROPERTYKEY()], Throws.Exception);
Assert.That(() => i.Properties[new PROPERTYKEY(Guid.NewGuid(), 2)], Throws.Exception);
Assert.That(i.Properties["System.Author"], Has.Member("TestAuthor"));
Assert.That(i.Properties["DocAuthor"], Has.Member("TestAuthor"));
Assert.That(() => i.Properties[null], Throws.Exception);
Assert.That(() => i.Properties["Arthur"], Throws.Exception);
Assert.That(i.Properties.GetProperty<string>(PROPERTYKEY.System.Company), Is.InstanceOf<string>().And.StartWith("Microsoft"));
Assert.That(() => i.Properties.GetProperty<int>(PROPERTYKEY.System.Company), Throws.Exception);
}
}
@ -147,15 +157,14 @@ namespace Vanara.Windows.Forms.Tests
{
using (var i = new ShellItem(testDoc))
{
var pk = PROPERTYKEY.System.Category;
Assert.That(() => i.GetPropertyDescriptionList(ref pk), Throws.Exception);
pk = PROPERTYKEY.System.PropList.FullDetails;
using (var pdl = i.GetPropertyDescriptionList(ref pk))
Assert.That(() => i.GetPropertyDescriptionList(PROPERTYKEY.System.Category), Throws.Exception);
using (var pdl = i.GetPropertyDescriptionList(PROPERTYKEY.System.PropList.FullDetails))
{
Assert.That(pdl.Count, Is.GreaterThan(0));
foreach (var d in pdl)
{
Assert.That(d.TypeFlags, Is.Not.Zero);
Debug.WriteLine($"Property '{d.DisplayName}' is of type '{d.PropertyType}'");
}
}
}
@ -190,12 +199,12 @@ namespace Vanara.Windows.Forms.Tests
Assert.That(ps, Is.Not.Null.And.InstanceOf<PropSys.IPropertyStore>());
System.Runtime.InteropServices.Marshal.ReleaseComObject(ps);
Assert.That(() => i.GetHandler<IExtractIcon>(), Throws.TypeOf<ArgumentOutOfRangeException>());
}
}
}
}
[Test]
public void GetImageTest()
{
[Test]
public void GetImageTest()
{
using (var i = new ShellItem(testDoc))
{
var sz = new System.Drawing.Size(32, 32);
@ -207,8 +216,8 @@ namespace Vanara.Windows.Forms.Tests
{
var sz = new System.Drawing.Size(1024, 1024);
var bmp = i.GetImage(sz, ShellItemGetImageOptions.ThumbnailOnly | ShellItemGetImageOptions.ScaleUp);
Assert.That(bmp.Size, Is.EqualTo(sz));
}
}
}
Assert.That(bmp.Size, Is.EqualTo(sz));
}
}
}
}

151
Windows.Shell/PropertyDescription.cs
View File

@ -11,12 +11,17 @@ namespace Vanara.Windows.Shell
{
/// <summary>The IPropertyDescription object.</summary>
protected IPropertyDescription iDesc;
/// <summary>The IPropertyDescription2 object.</summary>
protected IPropertyDescription2 iDesc2;
/// <summary>Gets the type list.</summary>
protected PropertyTypeList typeList;
/// <summary>Initializes a new instance of the <see cref="PropertyDescription"/> class.</summary>
/// <param name="propertyDescription">The property description.</param>
internal PropertyDescription(IPropertyDescription propertyDescription)
internal protected PropertyDescription(IPropertyDescription propertyDescription)
{
iDesc = propertyDescription;
iDesc = propertyDescription ?? throw new ArgumentNullException(nameof(propertyDescription));
}
/// <summary>Gets a value that describes how the property values are displayed when multiple items are selected in the UI.</summary>
@ -53,15 +58,9 @@ namespace Vanara.Windows.Shell
/// <summary>Gets a structure that acts as a property's unique identifier.</summary>
public PROPERTYKEY PropertyKey => iDesc.GetPropertyKey();
/// <summary>Gets the variant type of the property.</summary>
public Type PropertyType
{
get
{
throw new NotImplementedException();
//TODO: return iDesc.GetPropertyType().GetType();
}
}
/// <summary>Gets the variant type of the property. If the type cannot be determined, this property returns <c>null</c>.</summary>
public Type PropertyType => PROPVARIANT.GetType(iDesc.GetPropertyType());
/// <summary>Gets the relative description type for a property description.</summary>
public PROPDESC_RELATIVEDESCRIPTION_TYPE RelativeDescriptionType => iDesc.GetRelativeDescriptionType();
@ -71,6 +70,9 @@ namespace Vanara.Windows.Shell
/// <summary>Gets a set of flags that describe the uses and capabilities of the property.</summary>
public PROPDESC_TYPE_FLAGS TypeFlags => iDesc.GetTypeFlags(PROPDESC_TYPE_FLAGS.PDTF_MASK_ALL);
/// <summary>Gets an instance of an PropertyTypeList, which can be used to enumerate the possible values for a property.</summary>
public PropertyTypeList TypeList => typeList ?? (typeList = new PropertyTypeList(iDesc.GetEnumTypeList() as IPropertyEnumTypeList));
/// <summary>Gets the current set of flags governing the property's view.</summary>
/// <returns>When this method returns, contains a pointer to a value that includes one or more of the following flags. See PROPDESC_VIEW_FLAGS for valid values.</returns>
public PROPDESC_VIEW_FLAGS ViewFlags => iDesc.GetViewFlags();
@ -82,27 +84,39 @@ namespace Vanara.Windows.Shell
/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
public virtual void Dispose()
{
typeList?.Dispose();
if (iDesc2 != null)
{
Marshal.ReleaseComObject(iDesc2);
iDesc2 = null;
}
if (iDesc != null)
{
Marshal.ReleaseComObject(iDesc);
iDesc = null;
}
}
// /// <summary>Gets an instance of an IPropertyEnumTypeList, which can be used to enumerate the possible values for a property.</summary>
// public IPropertyEnumTypeList EnumTypeList => iDesc.GetEnumTypeList() as IPropertyEnumTypeList;
/// <summary>Gets a formatted string representation of a property value.</summary>
/// <param name="key">A reference to the requested property key, which identifies a property. See PROPERTYKEY.</param>
/// <param name="propvar">A PROPVARIANT that contains the type and value of the property.</param>
/// <param name="pdfFlags">One or more of the PROPDESC_FORMAT_FLAGS flags, which are either bitwise or multiple values, that indicate the property string format.</param>
/// <returns>The formatted value.</returns>
public string FormatForDisplay(ref PROPERTYKEY key, PROPVARIANT propvar, PROPDESC_FORMAT_FLAGS pdfFlags)
public string FormatForDisplay(PROPVARIANT propvar, PROPDESC_FORMAT_FLAGS pdfFlags = PROPDESC_FORMAT_FLAGS.PDFF_DEFAULT)
{
var sb = new System.Text.StringBuilder(0x8000);
var key = PropertyKey;
iDesc.FormatForDisplay(ref key, propvar, pdfFlags, sb, (uint)sb.Capacity);
return sb.ToString();
}
/// <summary>Gets the image location for a value.</summary>
/// <param name="propvar">The value.</param>
/// <returns>An IconLocation for the image associated with the property value.</returns>
public IconLocation GetImageLocationForValue(PROPVARIANT propvar)
{
if (iDesc2 == null) iDesc2 = iDesc as IPropertyDescription2;
return IconLocation.TryParse(iDesc2?.GetImageReferenceForValue(propvar), out var loc) ? loc : new IconLocation();
}
/// <summary>Compares two property values in the manner specified by the property description. Returns two display strings that describe how the two properties compare.</summary>
/// <param name="propvar1">A reference to a PROPVARIANT structure that contains the type and value of the first property.</param>
/// <param name="propvar2">A reference to a PROPVARIANT structure that contains the type and value of the second property.</param>
@ -122,18 +136,30 @@ namespace Vanara.Windows.Shell
public bool IsValueCanonical(PROPVARIANT propvar) => iDesc.IsValueCanonical(propvar).Succeeded;
}
/// <summary>Exposes methods that extract information from a collection of property descriptions presented as a list.</summary>
/// <seealso cref="System.Collections.Generic.IReadOnlyList{Vanara.Windows.Shell.PropertyDescription}"/>
/// <seealso cref="System.IDisposable"/>
public class PropertyDescriptionList : IReadOnlyList<PropertyDescription>, IDisposable
{
/// <summary>The IPropertyDescriptionList instance.</summary>
protected IPropertyDescriptionList iList;
internal PropertyDescriptionList(IPropertyDescriptionList list)
/// <summary>Initializes a new instance of the <see cref="PropertyDescriptionList"/> class.</summary>
/// <param name="list">The COM interface pointer.</param>
internal protected PropertyDescriptionList(IPropertyDescriptionList list)
{
iList = list;
iList = list ?? throw new ArgumentNullException(nameof(list));
}
public int Count => (int)iList.GetCount();
/// <summary>Gets the number of elements in the collection.</summary>
/// <value>The number of elements in the collection.</value>
public virtual int Count => (int)iList.GetCount();
public PropertyDescription this[int index] => new PropertyDescription(iList.GetAt((uint)index, typeof(IPropertyDescription).GUID));
/// <summary>Gets the <see cref="PropertyDescription"/> at the specified index.</summary>
/// <value>The <see cref="PropertyDescription"/>.</value>
/// <param name="index">The index.</param>
/// <returns>The <see cref="PropertyDescription"/> at the specified index.</returns>
public virtual PropertyDescription this[int index] => new PropertyDescription(iList.GetAt((uint)index, typeof(IPropertyDescription).GUID));
/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
public virtual void Dispose()
@ -145,11 +171,17 @@ namespace Vanara.Windows.Shell
}
}
/// <summary>Returns an enumerator that iterates through the collection.</summary>
/// <returns>A <see cref="T:System.Collections.Generic.IEnumerator`1"/> that can be used to iterate through the collection.</returns>
public IEnumerator<PropertyDescription> GetEnumerator() => Enum().GetEnumerator();
/// <summary>Returns an enumerator that iterates through a collection.</summary>
/// <returns>An <see cref="T:System.Collections.IEnumerator"/> object that can be used to iterate through the collection.</returns>
IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
private IEnumerable<PropertyDescription> Enum()
/// <summary>Enumerates through the items in this instance.</summary>
/// <returns>An <see cref="IEnumerable{PropertyDescription}"/> for this list.</returns>
protected virtual IEnumerable<PropertyDescription> Enum()
{
for (var i = 0; i < Count; i++)
yield return this[i];
@ -157,30 +189,56 @@ namespace Vanara.Windows.Shell
}
}
/// <summary>Exposes methods that extract data from enumeration information.</summary>
/// <seealso cref="System.IDisposable"/>
public class PropertyType : IDisposable
{
/// <summary>The IPropertyEnumType instance.</summary>
protected IPropertyEnumType iType;
/// <summary>The IPropertyEnumType2 instance.</summary>
protected IPropertyEnumType2 iType2;
internal PropertyType(IPropertyEnumType type)
/// <summary>Initializes a new instance of the <see cref="PropertyType"/> class.</summary>
/// <param name="type">The IPropertyEnumType object.</param>
internal protected PropertyType(IPropertyEnumType type)
{
iType = type;
iType2 = type as IPropertyEnumType2;
iType = type ?? throw new ArgumentNullException(nameof(type));
}
/// <summary>Gets the display text.</summary>
/// <value>The display text.</value>
public string DisplayText => iType.GetDisplayText();
/// <summary>Gets an enumeration type.</summary>
/// <value>The enumeration type.</value>
public PROPENUMTYPE EnumType => iType.GetEnumType();
public IconLocation ImageReference { get { if (IconLocation.TryParse(iType2?.GetImageReference(), out var loc)) return loc; return new IconLocation(); } }
/// <summary>Gets the image reference.</summary>
/// <value>The image reference.</value>
public IconLocation ImageReference
{
get
{
if (iType2 == null) iType2 = iType as IPropertyEnumType2;
return IconLocation.TryParse(iType2?.GetImageReference(), out var loc) ? loc : new IconLocation();
}
}
/// <summary>Gets a minimum value.</summary>
/// <value>The minimum value.</value>
public PROPVARIANT RangeMinValue => iType.GetRangeMinValue();
/// <summary>Gets a set value.</summary>
/// <value>The set value.</value>
public PROPVARIANT RangeSetValue => iType.GetRangeSetValue();
/// <summary>Gets a value.</summary>
/// <value>The value.</value>
public PROPVARIANT Value => iType.GetValue();
/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public virtual void Dispose()
{
if (iType != null)
@ -196,20 +254,34 @@ namespace Vanara.Windows.Shell
}
}
/// <summary>Exposes methods that enumerate the possible values for a property.</summary>
/// <seealso cref="System.Collections.Generic.IReadOnlyList{Vanara.Windows.Shell.PropertyType}"/>
/// <seealso cref="System.IDisposable"/>
public class PropertyTypeList : IReadOnlyList<PropertyType>, IDisposable
{
/// <summary>The IPropertyEnumTypeList object.</summary>
protected IPropertyEnumTypeList iList;
internal PropertyTypeList(IPropertyEnumTypeList list)
/// <summary>Initializes a new instance of the <see cref="PropertyTypeList"/> class.</summary>
/// <param name="list">The IPropertyEnumTypeList object.</param>
internal protected PropertyTypeList(IPropertyEnumTypeList list)
{
iList = list;
iList = list ?? throw new ArgumentNullException(nameof(list));
}
public int Count => (int)iList.GetCount();
/// <summary>Gets the number of elements in the collection.</summary>
/// <value>The number of elements in the collection.</value>
public virtual int Count => (int)iList.GetCount();
public PropertyType this[int index] => new PropertyType(iList.GetAt((uint)index, typeof(IPropertyDescription).GUID));
/// <summary>Gets the <see cref="PropertyType"/> at the specified index.</summary>
/// <value>The <see cref="PropertyType"/>.</value>
/// <param name="index">The index.</param>
/// <returns>The <see cref="PropertyType"/> at the specified index.</returns>
public virtual PropertyType this[int index] => new PropertyType(iList.GetAt((uint)index, typeof(IPropertyDescription).GUID));
/// <summary>Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.</summary>
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public virtual void Dispose()
{
if (iList != null)
@ -219,13 +291,26 @@ namespace Vanara.Windows.Shell
}
}
public int FindMatchingIndex(PROPVARIANT pv) => (int)iList.FindMatchingIndex(pv);
/// <summary>Determines the index of a specific item in the list.</summary>
/// <param name="pv">The object to locate in the list.</param>
/// <returns>The index of item if found in the list; otherwise, -1.</returns>
public virtual int IndexOf(PROPVARIANT pv) => iList.FindMatchingIndex(pv, out var idx).Succeeded ? (int)idx : -1;
/// <summary>Returns an enumerator that iterates through the collection.</summary>
/// <returns>
/// A <see cref="T:System.Collections.Generic.IEnumerator`1" /> that can be used to iterate through the collection.
/// </returns>
public IEnumerator<PropertyType> GetEnumerator() => Enum().GetEnumerator();
/// <summary>Returns an enumerator that iterates through a collection.</summary>
/// <returns>
/// An <see cref="T:System.Collections.IEnumerator" /> object that can be used to iterate through the collection.
/// </returns>
IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
private IEnumerable<PropertyType> Enum()
/// <summary>Enumerates through the items in this instance.</summary>
/// <returns>An <see cref="IEnumerable{PropertyType}"/> for this list.</returns>
protected virtual IEnumerable<PropertyType> Enum()
{
for (var i = 0; i < Count; i++)
yield return this[i];

29
Windows.Shell/PropertyStore.cs
View File

@ -4,6 +4,7 @@ using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Runtime.InteropServices;
using Vanara.PInvoke;
using static Vanara.PInvoke.Ole32;
using static Vanara.PInvoke.PropSys;
@ -97,7 +98,10 @@ namespace Vanara.Windows.Shell
/// <returns>The requested property key.</returns>
public static PROPERTYKEY GetPropertyKeyFromName(string name)
{
PSGetPropertyKeyFromName(name, out var pk).ThrowIfFailed();
if (name == null) throw new ArgumentNullException(nameof(name));
var hr = PSGetPropertyKeyFromName(name, out var pk);
if (hr == HRESULT.TYPE_E_ELEMENTNOTFOUND) throw new ArgumentOutOfRangeException(nameof(name));
hr.ThrowIfFailed();
return pk;
}
@ -187,8 +191,11 @@ namespace Vanara.Windows.Shell
{
var pv = new PROPVARIANT();
iprops.GetValue(ref key, pv);
value = pv.Value;
return true;
if (pv.VarType != VarEnum.VT_EMPTY)
{
value = pv.Value;
return true;
}
}
catch { }
}
@ -208,19 +215,9 @@ namespace Vanara.Windows.Shell
/// </returns>
public bool TryGetValue<TVal>(PROPERTYKEY key, out TVal value)
{
if (iprops != null)
{
try
{
var pv = new PROPVARIANT();
iprops.GetValue(ref key, pv);
value = (TVal)pv.Value;
return true;
}
catch { }
}
value = default(TVal);
return false;
var ret = TryGetValue(key, out var val);
value = ret ? (TVal)val : default(TVal);
return ret;
}
/// <summary>Adds an item to the <see cref="ICollection{T}"/>.</summary>

69
Windows.Shell/ShellItem.cs
View File

@ -353,8 +353,8 @@ namespace Vanara.Windows.Shell
internal IShellItem iShellItem;
internal IShellItem2 iShellItem2;
private static Dictionary<Type, BHID> bhidLookup;
private IQueryInfo qi;
private ShellItemPropertyStore values;
private IQueryInfo qi;
private ShellItemPropertyStore values;
/// <summary>Initializes a new instance of the <see cref="ShellItem"/> class.</summary>
/// <param name="path">The file system path of the item.</param>
@ -423,8 +423,8 @@ namespace Vanara.Windows.Shell
/// <value>The attributes of the Shell item.</value>
public ShellItemAttribute Attributes => (ShellItemAttribute)iShellItem.GetAttributes((SFGAO)0xFFFFFFFF);
/// <summary>Gets the <see cref="ShellFileInfo"/> corresponding to this instance.</summary>
public ShellFileInfo FileInfo => IsFileSystem ? new ShellFileInfo(PIDL) : throw new InvalidOperationException("Not file system objects do not have associated ShellFileInfo objects");
/// <summary>Gets the <see cref="ShellFileInfo"/> corresponding to this instance.</summary>
public ShellFileInfo FileInfo => IsFileSystem ? new ShellFileInfo(PIDL) : throw new InvalidOperationException("Not file system objects do not have associated ShellFileInfo objects");
/// <summary>Gets the file system path if this item is part of the file system.</summary>
/// <value>The file system path.</value>
@ -558,16 +558,16 @@ namespace Vanara.Windows.Shell
/// <returns>The requested interface.</returns>
public TInterface GetHandler<TInterface>(BHID handler = 0) where TInterface : class
{
if (handler == 0)
handler = GetBHIDForInterface<TInterface>();
if (handler == 0)
throw new ArgumentOutOfRangeException(nameof(handler));
return iShellItem.BindToHandler(BindContext, handler.Guid(), typeof(TInterface).GUID) as TInterface;
if (handler == 0)
handler = GetBHIDForInterface<TInterface>();
if (handler == 0)
throw new ArgumentOutOfRangeException(nameof(handler));
return iShellItem.BindToHandler(BindContext, handler.Guid(), typeof(TInterface).GUID) as TInterface;
}
/// <summary>Returns a hash code for this instance.</summary>
/// <returns>A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.</returns>
public override int GetHashCode() => GetDisplayName(SIGDN.SIGDN_DESKTOPABSOLUTEPARSING).GetHashCode();
/// <summary>Returns a hash code for this instance.</summary>
/// <returns>A hash code for this instance, suitable for use in hashing algorithms and data structures like a hash table.</returns>
public override int GetHashCode() => GetDisplayName(SIGDN.SIGDN_DESKTOPABSOLUTEPARSING).GetHashCode();
/// <summary>
/// Gets an image that represents this item. The default behavior is to load a thumbnail. If there is no thumbnail for the current item, it retrieves the
@ -595,10 +595,14 @@ namespace Vanara.Windows.Shell
throw new InvalidOperationException("Unable to retrieve an image for this item.");
}
/// <summary>Gets a property description list object containing descriptions of all properties.</summary>
/// <returns>A complete <see cref="PropertyDescriptionList"/> instance.</returns>
public PropertyDescriptionList GetPropertyDescriptionList() => GetPropertyDescriptionList(PROPERTYKEY.System.PropList.FullDetails);
/// <summary>Gets a property description list object given a reference to a property key.</summary>
/// <param name="keyType">A reference to a PROPERTYKEY structure.</param>
/// <param name="keyType">A reference to a PROPERTYKEY structure. The values in <see cref="PROPERTYKEY.System.PropList"/> are all valid. <see cref="PROPERTYKEY.System.PropList.FullDetails"/> will return all properties.</param>
/// <returns>A <see cref="PropertyDescriptionList"/> instance for the supplied key.</returns>
public PropertyDescriptionList GetPropertyDescriptionList(ref PROPERTYKEY keyType)
public PropertyDescriptionList GetPropertyDescriptionList(PROPERTYKEY keyType)
{
ThrowIfNoShellItem2();
return new PropertyDescriptionList(iShellItem2.GetPropertyDescriptionList(ref keyType, typeof(IPropertyDescriptionList).GUID));
@ -627,6 +631,7 @@ namespace Vanara.Windows.Shell
/// <summary>Ensures that all cached information for this item is updated.</summary>
public void Update()
{
values?.Commit();
ThrowIfNoShellItem2();
iShellItem2.Update(BindContext);
}
@ -777,24 +782,24 @@ namespace Vanara.Windows.Shell
/// <param name="width">The width, in pixels, of the Bitmap.</param>
/// <returns>The resulting Bitmap, on success, or <c>null</c> on failure.</returns>
private Image GetThumbnail(int width = 32)
{
IThumbnailProvider provider = null;
try
{
provider = GetHandler<IThumbnailProvider>(BHID.BHID_ThumbnailHandler);
if (provider == null) return null;
provider.GetThumbnail((uint)width, out var hbmp, out var alpha);
return Image.FromHbitmap(hbmp);
}
catch
{
return null;
}
finally
{
if (provider != null) Marshal.ReleaseComObject(provider);
}
}
{
IThumbnailProvider provider = null;
try
{
provider = GetHandler<IThumbnailProvider>(BHID.BHID_ThumbnailHandler);
if (provider == null) return null;
provider.GetThumbnail((uint)width, out var hbmp, out var alpha);
return Image.FromHbitmap(hbmp);
}
catch
{
return null;
}
finally
{
if (provider != null) Marshal.ReleaseComObject(provider);
}
}
protected class ShellItemImpl : IDisposable, IShellItem
{