可以查看添加监听器的对象

例如，您可以在控制台中登录已创建的标记，并通过marker.__e3_.click深入了解其事件侦听器对象。
下面是一个示例代码，它显示了一个标记的对象，如果它有一个事件监听器或没有：

// instantiate the marker
    marker = new Marker({
        map,
        draggable: true,
        position: {lat: -34.397, lng: 150.644},
    })
    
    // This adds a click event listener to your marker 
    let markerListenerEvent = event.addListener(marker, "click", function() {
        alert("you have clicked the marker!")
    });
    
    // this will show in the console that 
    // the marker now have a click event listener.
    console.log("clickable marker: ");
    console.log(marker.__e3_.click[64].So);
    // this will return "true"
    
    
  // clicking on the map will then remove the listener you put
    // on the marker
    let mapListenerEvent = event.addListener(map, "click", function() {
        alert("You have now removed the marker event listener!")
        // This is the the method that removes the listener for marker above
        event.removeListener(markerListenerEvent);
        
        // this will show in the console that 
        // the marker now don't have a click event listener
        // since the "click" object will now be empty.
        console.log("not clickable marker: ");
        console.log(marker.__e3_.click);
        // this will return an empty object because the listener has been removed
    })

如果你没有使用Google Maps React Library，而只是使用ReactJS，这应该可以正常工作。
下面是一个概念验证片段，您可以使用它（请使用您自己的API KEY）：https://jsbin.com/jovajor/1/edit?html,js,output

• 注意：我使用了外部Playground，以便您可以检查控制台。*

希望这有帮助！