DEV_QUERY_FLAGS enumeration (devquerydef.h)

Specifies flags that alter device query behavior.

Syntax

typedef enum _DEV_QUERY_FLAGS {
  DevQueryFlagNone,
  DevQueryFlagUpdateResults,
  DevQueryFlagAllProperties,
  DevQueryFlagLocalize,
  DevQueryFlagAsyncClose
} DEV_QUERY_FLAGS, *PDEV_QUERY_FLAGS;

Constants

DevQueryFlagNone No flags specified.
DevQueryFlagUpdateResults By default, queries do not receive updates. However, when a query registers for updates and specifies the DevQueryFlagUpdateResults flag, its result-set will continue to be updated by callbacks as changes in the system occurs that add or remove objects or change objects so that they now match, or no longer match the filter expression.
DevQueryFlagAllProperties Return all properties in all languages that exist for the object. See DevQueryFlagLocalize because it can modify this behavior.
DevQueryFlagLocalize When specified, properties of type DEVPROP_TYPE_STRING_INDIRECT are resolved to the calling thread's UI language. Multi-language properties are retrieved in the preferred language of the calling application. If used in conjunction with DevQueryFlagAllProperties, values for all property keys for the object will be fetched in the preferred language of the calling application.
DevQueryFlagAsyncClose This flag modifies the behavior of the DevCloseObjectQuery function. When it is specified, DevCloseObjectQuery will return immediately, but the callback function will continue to be invoked until a DevQueryStateClosed state change is received. When DevQueryFlagAsyncClose is not specified, DevCloseObjectQuery will block until an outstanding callback returns, and no further callbacks will occur once the DevCloseObjectQuery returns. In either case, a reference is held on the DLL where the callback function is implemented to ensure that it won't be unloaded while callbacks can still be invoked.

Requirements

Requirement	Value
Header	devquerydef.h