IPropertySystem::FormatForDisplay method (propsys.h)

Article
07/27/2022

Gets a formatted, Unicode string representation of a property value.

Syntax

HRESULT FormatForDisplay(
  [in]  REFPROPERTYKEY        key,
  [in]  REFPROPVARIANT        propvar,
  [in]  PROPDESC_FORMAT_FLAGS pdff,
  [out] LPWSTR                pszText,
  [in]  DWORD                 cchText
);

Parameters

[in] key

Type: REFPROPERTYKEY

A reference to the requested property key.

[in] propvar

Type: REFPROPVARIANT

A reference to a PROPVARIANT structure containing the type and value of the property.

[in] pdff

Type: PROPDESC_FORMAT_FLAGS

The format of the property string. See PROPDESC_FORMAT_FLAGS for possible values.

[out] pszText

Type: LPWSTR

Receives the formatted value as a null-terminated, Unicode string. The calling application must allocate memory for the buffer.

[in] cchText

Type: DWORD

The length of the buffer at pszText in WCHARs, including the terminating NULL. The maximum size is 0x8000 (32K).

Return value

Type: HRESULT

Returns one of the following values.

Return code	Description
S_OK	Formatted string is created.
S_FALSE	Formatted string is not created. S_FALSE indicates that the empty string resulted from a VT_EMPTY.
E_OUTOFMEMORY	Memory allocation failed.

Remarks

You must initialize Component Object Model (COM) with CoInitialize or OleInitialize before calling IPropertySystem::FormatForDisplay.

When it succeeds, this method gets a formatted Unicode string representation of a property value for a specified PROPERTYKEY, and one or more PROPDESC_FORMAT_FLAGS. If the PROPERTYKEY is not recognized by the schema subsystem, IPropertySystem::FormatForDisplay attempts to format the value according to its VARTYPE.

The purpose of this method is to convert data into a string suitable for display to the user. The value is formatted according to the current locale, the language of the user, the PROPDESC_FORMAT_FLAGS, and the property description specified by the property key. For information about how the property description schema influences the formatting of the value, see displayInfo, stringFormat, booleanFormat, numberFormat, NMDATETIMEFORMAT, and enumeratedList. Typically, the PROPDESC_FORMAT_FLAGS are used to modify the format prescribed by the property description.

The output string may contain Unicode directional characters. These nonspacing characters influence the Unicode bidirectional algorithm so that the values appear correctly when a left-to-right (LTR) language is drawn on a right-to-left (RTL) window, and vice versa. These characters include the following: "\x200e", "\x200f", "\x202a", "\x202b", "\x202c", "\x202d", "\x202e".

The properties in the following table use special formats and are unaffected by the PROPDESC_FORMAT_FLAGS (examples cited are for strings with a current locale set to English; typically, output is localized except where noted).

Property	Format
System.FileAttributes	The following file attributes are converted to letters and appended to create a string (for example, a value of 0x1801 (FILE_ATTRIBUTE_READONLY \| FILE_ATTRIBUTE_COMPRESSED \| FILE_ATTRIBUTE_OFFLINE) is converted to "RCO"): FILE_ATTRIBUTE_READONLY (0x00000001) - 'R' FILE_ATTRIBUTE_SYSTEM (0x00000004) - 'S' FILE_ATTRIBUTE_ARCHIVE (0x00000020) -'A' FILE_ATTRIBUTE_COMPRESSED (0x00000800) - 'C' FILE_ATTRIBUTE_ENCRYPTED (0x00004000) - 'E' FILE_ATTRIBUTE_OFFLINE (0x00001000) - 'O' FILE_ATTRIBUTE_NOT_CONTENT_INDEXED (0x00002000) - 'I'
System.Photo.ISOSpeed	For example, "ISO-400".
System.Photo.ShutterSpeed	The APEX value is converted to an exposure time using this formula: `Exposure_time = 2^(-APEX_value)` For example, "2 sec."or "1/125 sec.".
System.Photo.ExposureTime	For example, "2 sec."or "1/125 sec."
System.Photo.Aperture	The APEX value is converted to an F number using this formula: `F_Number = 2^(APEX_Value / 2)` For example, "f/5.6".
System.Photo.FNumber	For example, "f/5.6".
System.Photo.SubjectDistance	For example, "15 m"or "250 mm".
System.Photo.FocalLength	For example, "50 mm".
System.Photo.FlashEnergy	For example, "500 bpcs".
System.Photo.ExposureBias	For example, "-2 step", " 0 step", or "+3 step".
System.Computer.DecoratedFreeSpace	For example, "105 MB free of 13.2 GB".
System.ItemType	For example, "Application" or "JPEG Image".
System.ControlPanel.Category	For example, "Appearance and Personalization".
System.ComputerName	For example, "LITWARE05 (this computer)" or "testbox07".

If the property key does not correspond to a property description in any of the registered property schemas, this method chooses a format based on the type of the value, as described in the following table.

Type of the value	Format
VT_BOOLEAN	Not supported.
VT_FILETIME	Date/time string as specified by PROPDESC_FORMAT_FLAGS and the current locale. PDFF_SHORTTIME and PDFF_SHORTDATE are the default. For example, "11/13/2006 3:22 PM".
Numeric VARTYPE	Decimal string in the current locale. For example, "42".
VT_LPWSTR or other	String. Sequences of "\r", "\t", or "\n" are replaced with a single space.
VT_VECTOR \| anything	Semicolon separated values—a semicolon is used regardless of locale.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Target Platform	Windows
Header	propsys.h
Redistributable	Windows Desktop Search (WDS) 3.0

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