ros talker listener主要基本api 介绍

1 ros::init

void ros::init	(	const M_string &	remappings,
		const std::string &	name,
		uint32_t	options = 0
	)

alternate ROS initialization function.

Parameters:

	remappings	A map<string, string> where each one constitutes a name remapping, or one of the special remappings like __name, __master, __ns, etc.
	name	Name of this node. The name must be a base name, ie. it cannot contain namespaces.
	options	[optional] Options to start the node with (a set of bit flags from ros::init_options)

Exceptions:

InvalidNodeNameException

If the name passed in is not a valid "base" name

Definition at line 386 of file init.cpp.

void ros::init	(	int &	argc,
		char **	argv,
		const std::string &	name,
		uint32_t	options = 0
	)

ROS initialization function.

This function will parse any ROS arguments (e.g., topic name remappings), and will consume them (i.e., argc and argv may be modified as a result of this call).

Use this version if you are using the NodeHandle API

Parameters:

	argc
	argv
	name	Name of this node. The name must be a base name, ie. it cannot contain namespaces.
	options	[optional] Options to start the node with (a set of bit flags from ros::init_options)

Exceptions:

InvalidNodeNameException

If the name passed in is not a valid "base" name

对name中部分做些解释

ROS中图资源命名包括四种格式: base/relative/global/private, 大概是这个样子:

• base
• relative/name
• /global/name
• ~private/name

也就是说直接名字开头的不以/开头的表示base names, 这种方式是最常用的, 因为可以方便的remapping到其他namespace.而以/开头的表示global names, 这种方式不推荐用, 因为这样写出来的代码不太方便移植.

2 ros::publisher

ros::Publisher::Publisher	(	const std::string &	topic,
		const std::string &	md5sum,
		const std::string &	datatype,
		const NodeHandle &	node_handle,
		const SubscriberCallbacksPtr &	callbacks
	)		[private]

Definition at line 59 of file publisher.cpp.

---

Member Function Documentation

其中有一个publish的成员比较常用

void ros::Publisher::publish

(

const M &

message

)

const [inline]

Publish a message on the topic associated with this Publisher.

Definition at line 95 of file publisher.h.

void ros::Publisher::publish	(	const boost::function< SerializedMessage(void)> &	serfunc,
		SerializedMessage &	m
	)		const [private]

Definition at line 78 of file publisher.cpp.

使用用法：

ros::Publisher chatter_pub = n.advertise<std_msgs::String>("chatter", 1000);chatter_pub.publish(msg);

3 ros::Subscriber 

Public Member Functions
uint32_t	getNumPublishers () const
	Returns the number of publishers this subscriber is connected to.
std::string	getTopic () const
	operator void * () const
bool	operator!= (const Subscriber &rhs) const
bool	operator< (const Subscriber &rhs) const
bool	operator== (const Subscriber &rhs) const
void	shutdown ()
	Unsubscribe the callback associated with this Subscriber.
	Subscriber ()
	Subscriber (const Subscriber &rhs)
	~Subscriber ()

Private Member Functions
	Subscriber (const std::string &topic, const NodeHandle &node_handle, const SubscriptionCallbackHelperPtr &helper)

ros::Subscriber::Subscriber	(	const std::string &	topic,
		const NodeHandle &	node_handle,
		const SubscriptionCallbackHelperPtr &	helper
	)

Detailed Description

Manages an subscription callback on a specific topic.

A Subscriber should always be created through a call to NodeHandle::subscribe(), or copied from one that was. Once all copies of a specific Subscriber go out of scope, the subscription callback associated with that handle will stop being called. Once all Subscriber for a given topic go out of scope the topic will be unsubscribed.

使用示例：ros::Subscriber sub = n.subscribe("chatter", 1000, chatterCallback);

4 ros::Rate

Public Member Functions
Duration	cycleTime ()
	Get the actual run time of a cycle from start to sleep.
Duration	expectedCycleTime ()
	Get the expected cycle time -- one over the frequency passed in to the constructor.
	Rate (double frequency)
	Constructor, creates a Rate.
void	reset ()
	Sets the start time for the rate to now.
bool	sleep ()
	Sleeps for any leftover time in a cycle. Calculated from the last time sleep, reset, or the constructor was called.

5 ROS_INFO 类似与格式化输出函数printf()

ros::spinOnce();开始整个node回调函数处理