DeviceThumbnail Class

Reference

Definition

Namespace:: Windows.Devices.Enumeration

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Edit

Represents the thumbnail image for a device.

public ref class DeviceThumbnail sealed : IClosable, IRandomAccessStreamWithContentType

/// [Windows.Foundation.Metadata.ContractVersion(Windows.Foundation.UniversalApiContract, 65536)]
/// [Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
class DeviceThumbnail final : IClosable, IRandomAccessStreamWithContentType

[Windows.Foundation.Metadata.ContractVersion(typeof(Windows.Foundation.UniversalApiContract), 65536)]
[Windows.Foundation.Metadata.MarshalingBehavior(Windows.Foundation.Metadata.MarshalingType.Agile)]
public sealed class DeviceThumbnail : System.IDisposable, IRandomAccessStreamWithContentType

Public NotInheritable Class DeviceThumbnail
Implements IDisposable, IRandomAccessStreamWithContentType

Inheritance: Object Platform::Object IInspectable DeviceThumbnail

Attributes: ContractVersionAttribute MarshalingBehaviorAttribute

Implements: IClosable IDisposable IContentTypeProvider IInputStream IOutputStream IRandomAccessStream IRandomAccessStreamWithContentType

Windows requirements

Device family	Windows 10 (introduced in 10.0.10240.0)
API contract	Windows.Foundation.UniversalApiContract (introduced in v1.0)

Examples

// Takes a parameter of type DeviceInformation
// and retrieves a DeviceThumbnail to pass to displayImage().
function getImage (device) {   

    var thumbnail = null;
    if (device){
        device.getThumbnailAsync().then(
            function (thumbnail) {
                if (thumbnail){      
                    if (thumbnail.size > 0) {
                        displayImage(thumbnail);
                    }                                                                      
                 }     
             });
    }                                                                                     
}

function displayImage(imageFile) {

    try {
        // Setting 2nd parameter to 'false' cleans up 
        // the URL after first use.
        // We set this because we only need to load the URL
        // into the image tag once.
        document.getElementById("deviceImage").src = 
            window.URL.createObjectURL(imageFile, false);
    } catch (e) {
        document.getElementById("statusMessage").innerHTML = 
            "Could not display image, error: " + e.message;
    }

}

Remarks

Call DeviceInformation.GetThumbnailAsync and handle the completion event as shown in the example.

Properties

CanRead	Gets a value that indicates whether the stream can be read from.
CanWrite	Gets a value that indicates whether the stream can be written to.
ContentType	Returns the content type of the thumbnail image.
Position	Gets the byte offset of the stream.
Size	Gets or sets the size of the device thumbnail image.

Methods

CloneStream()	Creates a new instance of a IRandomAccessStream over the same resource as the current stream.
Close()	Closes the current stream and releases system resources.
Dispose()	Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
FlushAsync()	Flushes data asynchronously in a sequential stream.
GetInputStreamAt(UInt64)	Returns a pointer to an input stream starting at the specified location.
GetOutputStreamAt(UInt64)	Returns a pointer to an output stream starting at the specified location.
ReadAsync(IBuffer, UInt32, InputStreamOptions)	Returns an asynchronous byte reader object.
Seek(UInt64)	Sets the position of the stream to the specified value.
WriteAsync(IBuffer)	Writes data asynchronously in a sequential stream.

Applies to

Udostępnij za pośrednictwem