添加監聽

Question

當創建像這樣我的Google map markers,

我添加事件監聽器 -

var infowindow = new google.maps.InfoWindow({ 
    content: 'Hi there from Alabama!' 
}); 

google.maps.event.addListener(marker, 'mouseover', function() { 
    infowindow.open(map, marker); // this displays the infowindow on mouseover 
}); 

google.maps.event.addListener(marker, 'mouseout', function() { 
    infowindow.close(); // this close the infowindow on mouseout 
}); 

marker.addListener('click', function() { 
    google.maps.event.clearListeners(marker, 'mouseout'); 
    // this removes the mouseout listener when the marker is clicked so that it stays 
    // present after mouseout. 
}); 

上述作品一種享受，但是我也希望能夠重新 - 在信息窗口關閉後添加mouseout事件。

我試過新增這給我的功能 -

google.maps.event.addListener(infowindow, 'closeclick', function() { 
    google.maps.event.addListener(marker, 'mouseout'); 
    // when the info window is closed the mouseout event is reinstated 
    // I also previously added an alert here to make sure it was hit! 
}); 

這將創建標記好了，但是在行動上，我可以點擊標記>鼠標移出和信息窗口保持目前>關閉infowindow。所有需要的行爲。

但是再次懸停在標記信息窗口顯示（如預期），但在碰到mouseout事件，我得到 -

JavaScript runtime error: Unable to get property 'apply' of undefined or null reference 

該錯誤是居住在谷歌API的JS文件，所以它是非常很難確定問題的根源在哪裏。如何正確地恢復mouseout事件infowindow關閉？

Answer 1

目前，您必須在事件分配一個匿名函數：

google.maps.event.addListener(marker, 'mouseout', function() { 
    infowindow.close(); // this close the infowindow on mouseout 
}); 

如果你創建了一個名爲功能，您可以添加這樣的：

function mouseoutHandler() { 
    infowindow.close(); // this close the infowindow on mouseout   
} 
google.maps.event.addListener(marker, 'mouseout', mouseoutHandler); 

然後，您可以將其刪除...

marker.addListener('click', function() { 
    google.maps.event.clearListeners(marker, 'mouseout'); 
    // this removes the mouseout listener when the marker is clicked so that it stays 
    // present after mouseout. 
}); 

後來，您只需重新添加事件，因爲您第一次做 - 因爲你有一個不適用med函數，你不會失去聲明！

---

如果你還在擊中拆除原事件的錯誤，你might try being more specific：

var listenerHandle = google.maps.event.addListener(marker, 'mouseout', mouseoutHandler); 
// later... 
google.maps.event.removeListener(listenerHandle);