如何正确接收dbus消息？

Question

我编写了以下 golang 程序作为

main.go

来学习 Go 中的 dbus :

package main

import (
    "fmt"
    "github.com/godbus/dbus/v5"
    "time"
)

// Listener function to listen for D-Bus signals
func runListener() {
    // Create a new D-Bus connection for the listener
    conn, err := dbus.SessionBus()
    if err != nil {
        fmt.Println("Listener: Failed to connect to session bus:", err)
        return
    }
    defer conn.Close()

    // Request a unique name for the listener
    busName := "org.example.Listener"
    if _, reqErr := conn.RequestName(busName, dbus.NameFlagDoNotQueue); reqErr != nil {
        fmt.Println("Listener: Failed to request name:", reqErr)
        return
    }
    fmt.Println("Listener: Listening for messages on", busName)

    // Add a match rule for the specific signal
    err = conn.AddMatchSignal(
        dbus.WithMatchInterface("org.example.ListenerInterface"), // Match interface
        dbus.WithMatchMember("Message"),                          // Match signal member
    )
    if err != nil {
        fmt.Println("Listener: Failed to add match rule:", err)
        return
    }

    // Create a channel to receive signals
    c := make(chan *dbus.Signal, 10)
    conn.Signal(c)

    // Listen for messages
    fmt.Println("Listener: Waiting for D-Bus messages...")
    for signal := range c {
        fmt.Printf("Listener: Received message: %v\n", signal.Body)
    }
}

// Sender function to send a D-Bus signal
func runSender() {
    // Wait briefly to ensure the listener is ready
    time.Sleep(2 * time.Second)

    // Create a new D-Bus connection for the sender
    conn, err := dbus.SessionBus()
    if err != nil {
        fmt.Println("Sender: Failed to connect to session bus:", err)
        return
    }
    defer conn.Close()

    // Define the signal details
    objectPath := dbus.ObjectPath("/org/example/Listener") // Convert string to ObjectPath
    interfaceName := "org.example.ListenerInterface"
    signalName := interfaceName + ".Message"

    // Emit the signal
    fmt.Println("Sender: Sending message to listener...")
    err = conn.Emit(objectPath, signalName, "Hello from the sender!")
    if err != nil {
        fmt.Println("Sender: Failed to send message:", err)
        return
    }

    fmt.Println("Sender: Message sent successfully!")
}

func main() {
    // Run the listener and sender as separate goroutines
    go runListener()
    go runSender()

    // Prevent the program from exiting immediately
    select {}
}

我遇到的问题是程序成功输出：

Listener: Listening for messages on org.example.Listener Listener:
Waiting for D-Bus messages... Sender: Sending message to listener...
Sender: Message sent successfully!

但请注意，没有“Listener：已收到消息”输出...

我还尝试使用两个单独的项目目录（监听器、发送器）中的两个单独的

main.go

文件来执行此操作，但我无法正确配置 GoLand 以同时运行这两个

main.go

文件，因为我得到了来自 GoLand 的错误：

package dbus_messenger is not in std (/usr/lib/golang/src/dbus_messenger) 

。

Answer 1

只需更改您的代码即可使用ConnectSessionBus。

SessionBus使用共享连接，可能会干扰消息接收。

SessionBus 返回一个到会话总线的共享连接，连接 如果还没有完成的话。

通过此更改，您的代码可以正常工作。

go run main.go 
Listener: Listening for messages on org.example.Listener
Listener: Waiting for D-Bus messages...
Sender: Sending message to listener...
Sender: Message sent successfully!
Listener: Received message: [Hello from the sender!]

它也可以使用

dbus-send

dbus-send --session \
  --dest=org.example.Listener \
  --type=signal \
  /org/example/Listener \
  org.example.ListenerInterface.Message \
  string:"Hello from dbus-send!"