/// <summary>
///
/// </summary>
/// <param name="device"></param>
/// <param name="propertyKey"></param>
/// <param name="propertyDataType"></param>
/// <param name="requiredSize"></param>
/// <returns></returns>
public static bool GetDeviceProperty(DeviceInfo device, DevicePropertyKey propertyKey,
out DevicePropertyType propertyDataType, out int requiredSize)
{
var deviceInfoList = device.InfoSet.InfoSet;
var deviceInfoData = device.InfoData;
var devicePropertyKey = propertyKey.PropertyKey;
var success = GetDeviceProperty(deviceInfoList, ref deviceInfoData, ref devicePropertyKey,
out propertyDataType, IntPtr.Zero, 0, out requiredSize, 0);
if (!success)
{
var lastError = ErrorHelpers.GetLastError();
return(lastError == ErrorCode.InsufficientBuffer);
}
return(true);
}
/// <summary>
///
/// </summary>
/// <param name="device"></param>
/// <param name="propertyKey"></param>
/// <param name="propertyDataType"></param>
/// <param name="propertyData"></param>
/// <returns></returns>
public static bool GetDeviceProperty(DeviceInfo device, DevicePropertyKey propertyKey,
out DevicePropertyType propertyDataType, out Api.Buffer propertyData)
{
var deviceInfoList = device.InfoSet.InfoSet;
var deviceInfoData = device.InfoData;
var devicePropertyKey = propertyKey.PropertyKey;
propertyData = new Api.Buffer();
int requiredSize;
// Keep trying until we've got success or an unrecoverable error.
while (true)
{
var success = GetDeviceProperty(deviceInfoList, ref deviceInfoData, ref devicePropertyKey,
out propertyDataType, propertyData.Data, propertyData.Length, out requiredSize, 0);
// If the data was read successfully, truncate the buffer to match the length read.
if (success)
{
propertyData.Truncate(requiredSize);
return(true);
}
// If the last error was for anything except the buffer being too small, cleanly get rid of the buffer
// before returning failure.
var lastError = ErrorHelpers.GetLastError();
if (lastError != ErrorCode.InsufficientBuffer)
{
propertyData.Dispose();
propertyData = null;
return(false);
}
// Resize the buffer to the required length before trying again.
propertyData.Resize(requiredSize);
}
}
/// <summary>
/// Gets the structure that represents a <see cref="DevicePropertyKey"/> at the API level.
/// </summary>
/// <param name="propertyKey">
/// The <see cref="DevicePropertyKey"/> being referenced in an API call.
/// </param>
/// <returns>A <see cref="DEVPROPKEY"/> structure.</returns>
public static DEVPROPKEY ToApiValue(this DevicePropertyKey propertyKey)
{
return(propertyKey.PropertyKey);
}
