get_message_objT_get_message_objGetMessageObjGetMessageObjget_message_obj (算子)

名称

get_message_objT_get_message_objGetMessageObjGetMessageObjget_message_obj — 从消息中检索与键关联的对象。

签名

get_message_obj( : ObjectData : MessageHandle, Key : )

描述

get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObjget_message_obj retrieves an object associated with the KeyKeyKeyKeykeykey from the message denoted by the MessageHandleMessageHandleMessageHandleMessageHandlemessageHandlemessage_handle. The object has to be previously stored to the message using set_message_objset_message_objSetMessageObjSetMessageObjSetMessageObjset_message_obj。

The operator returns the data in the parameter ObjectDataObjectDataObjectDataObjectDataobjectDataobject_data. The iconic object is copied by the operation. Therefore, clearing or reusing the message object afterwards will not have any side-effect on the returned iconic object, afterwards.

If the given KeyKeyKeyKeykeykey is not present in the message or if the data associated with the key is not an object, get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObjget_message_obj fails. Presence of keys and information about the data associated with the key can be verified using get_message_paramget_message_paramGetMessageParamGetMessageParamGetMessageParamget_message_param。

执行信息

多线程类型：可重入（与非独占算子并行运行）。
多线程作用域：全局（可从任何线程调用）。
未采用并行化处理。

参数

ObjectDataObjectDataObjectDataObjectDataobjectDataobject_data (输出对象) object(-array) → object

Tuple value retrieved from the message.

MessageHandleMessageHandleMessageHandleMessageHandlemessageHandlemessage_handle (输入控制) message → (handle)

Message handle.

元素数量： MessageHandle == 1

限制： MessageHandle != 0

KeyKeyKeyKeykeykey (输入控制) string → (string / integer)

Key string or integer.

元素数量： Key == 1

示例（HDevelop）

* ...
get_message_param (Message,'key_exists',['simple_string','foo','my_image'],\
                   KeysPresence)
get_message_param (Message,'key_data_type',['simple_string','my_image'],\
                   KeysType)
get_message_obj (Image, Message, 'my_image')

结果

If the operation succeeds, get_message_objget_message_objGetMessageObjGetMessageObjGetMessageObjget_message_obj 返回 2 ( H_MSG_TRUE )。否则将抛出异常。 Possible error conditions include invalid parameters (handle or key), the required key not found in the message or other than object data associated with given key.

可能的前趋

dequeue_messagedequeue_messageDequeueMessageDequeueMessageDequeueMessagedequeue_message

替代

get_message_tupleget_message_tupleGetMessageTupleGetMessageTupleGetMessageTupleget_message_tuple

另见

create_messagecreate_messageCreateMessageCreateMessageCreateMessagecreate_message, clear_messageclear_messageClearMessageClearMessageClearMessageclear_message, set_message_tupleset_message_tupleSetMessageTupleSetMessageTupleSetMessageTupleset_message_tuple, get_message_tupleget_message_tupleGetMessageTupleGetMessageTupleGetMessageTupleget_message_tuple, set_message_objset_message_objSetMessageObjSetMessageObjSetMessageObjset_message_obj, set_message_paramset_message_paramSetMessageParamSetMessageParamSetMessageParamset_message_param, get_message_paramget_message_paramGetMessageParamGetMessageParamGetMessageParamget_message_param, enqueue_messageenqueue_messageEnqueueMessageEnqueueMessageEnqueueMessageenqueue_message, dequeue_messagedequeue_messageDequeueMessageDequeueMessageDequeueMessagedequeue_message

模块

基础

算子