BitmapMetadata::SetQuery Method

Provides access to a metadata query writer that can write metadata to a bitmap image file.

Namespace:  System.Windows.Media.Imaging
Assembly:  PresentationCore (in PresentationCore.dll)

public:
void SetQuery(
	String^ query, 
	Object^ value
)

Parameters

query
Type: System::String

Identifies the location of the metadata to be written.

value
Type: System::Object

The value of the metadata to be written.

Metadata that is associated with an image is data that describes the image but that is not necessary for display of the image. Each supported bitmap image format handles metadata differently, but the facility for reading and writing metadata is the same.

Windows Presentation Foundation (WPF) supports the following image metadata schemas: Exchangeable image file (Exif), tEXt (PNG Textual Data), image file directory (IFD), International Press Telecommunications Council (IPTC), and Extensible Metadata Platform (XMP).

The following code example demonstrates how to use the SetQuery method to write metadata to a Portable Network Graphics (PNG) file.

Stream^ pngStream = gcnew FileStream("smiley.png", FileMode::Open, FileAccess::ReadWrite, FileShare::ReadWrite);
PngBitmapDecoder^ pngDecoder = gcnew PngBitmapDecoder(pngStream, BitmapCreateOptions::PreservePixelFormat, BitmapCacheOption::Default);
BitmapFrame^ pngFrame = pngDecoder->Frames[0];
InPlaceBitmapMetadataWriter^ pngInplace = pngFrame->CreateInPlaceBitmapMetadataWriter();
if (pngInplace->TrySave() == true)
{
   pngInplace->SetQuery("/Text/Description", "Have a nice day.");
}
pngStream->Close();

After the metadata is written, the GetQuery method is used to read that data and emit it as a text string.


// Add the metadata of the bitmap image to the text block.
TextBlock^ myTextBlock = gcnew TextBlock();
myTextBlock->Text = "The Description metadata of this image is: " + pngInplace->GetQuery("/Text/Description")->ToString();

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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