如何回复D-Bus消息 [英] How to reply a D-Bus message
问题描述
我得到了D-Bus server.c和client.c代码,并进行了一些修改. 我想要从client.c输入例如"hi"的结果 服务器将打印"receive message hi",并回复"reply_content !!!!!!"到client.c
I got the D-Bus server.c and client.c code, and made some modification. I want the result that when type for example "hi" from client.c server will print "receive message hi", and reply "reply_content!!!!!!" to client.c
但是现在看来client.c无法获得回复消息. 有人知道吗?
But it seems that now client.c cannot get the reply message. Anyone have the idea?
谢谢.
"server.c"
/* server.c */
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
DBusMessage *reply;
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message: %s\n", word);
handled = true;
reply = dbus_message_new_method_return(message);
char * reply_content = "reply_content!!!!!!";
dbus_message_append_args(reply, DBUS_TYPE_STRING, &reply_content, DBUS_TYPE_INVALID);
dbus_connection_send(connection, reply, NULL);
dbus_connection_flush(connection);
dbus_message_unref(reply);
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
dbus_bus_add_match(dbconn, "type='signal',interface='client.signal.Type'", &dberr);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
/* loop */
}
return 0;
}
这里是client.c
Here is client.c
#include <dbus/dbus.h>
#include <stdbool.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
static DBusHandlerResult
filter_func(DBusConnection *connection, DBusMessage *message, void *usr_data)
{
dbus_bool_t handled = false;
char *word = NULL;
DBusError dberr;
dbus_error_init(&dberr);
dbus_message_get_args(message, &dberr, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID);
printf("receive message %s\n", word);
handled = true;
return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}
int db_send(DBusConnection *dbconn)
{
DBusMessage *dbmsg;
char *word = (char *)malloc(sizeof(char));
int i;
dbmsg = dbus_message_new_signal("/client/signal/Object", "client.signal.Type", "Test");
scanf("%s", word);
if (!dbus_message_append_args(dbmsg, DBUS_TYPE_STRING, &word, DBUS_TYPE_INVALID)) {
return -1;
}
if (!dbus_connection_send(dbconn, dbmsg, NULL)) {
return -1;
}
dbus_connection_flush(dbconn);
printf("send message %s\n", word);
dbus_message_unref(dbmsg);
return 0;
}
int main(int argc, char *argv[])
{
DBusError dberr;
DBusConnection *dbconn;
dbus_error_init(&dberr);
dbconn = dbus_bus_get(DBUS_BUS_SESSION, &dberr);
if (!dbus_connection_add_filter(dbconn, filter_func, NULL, NULL)) {
return -1;
}
db_send(dbconn);
while(dbus_connection_read_write_dispatch(dbconn, -1)) {
db_send(dbconn);
}
dbus_connection_unref(dbconn);
return 0;
}
推荐答案
您目前仅与没有返回值的信号进行通信.
You're communicating only with signals at the moment, which don't have a return value.
在client.c中,使用dbus_message_new_method_call
代替dbus_message_new_signal
,在server.c中,您可能必须将type='signal'
更改为type='method_call'
.
In client.c, use dbus_message_new_method_call
instead of dbus_message_new_signal
, and in server.c you probably have to change type='signal'
to type='method_call'
.
这篇关于如何回复D-Bus消息的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!