Google Map + ASP.NET Series 1

I have made a little web page with google map api. Here are issues I dealed with.
Some of them are of ASP.NET, some of them are of Google Map.

Here are a little features description of my application.
1. Move to one of the marker and zoom in.
2. Pop up info window with information.
3. Showing the mouse Lat. and Lng.
4. Draging marker.
5. Show/hide maker’s name label.
6. Show/hide markers by category.
7. Show information of each station with label.
1-4 are features that provide by Google api.
5-7 are features that needs to work on.


The first thing you need to deal with will be ‘s onload and onunload event.
Google’s simple guide is adding an initialize() to onload and adding GUnload() to onunload.
It is not a good idea if you have your on master page and
make it runat=”server”, putting javascript functions to it.

I get around like this. A div with Id=”GMap” and runat=”server”.
In code-behind:
Page.ClientScript.RegisterStartupScript(this.GetType(), "OnLoad", string.Format("AddOnLoadFunctionParam(initialize,\"{0}\");", GMap.ClientID), true);
Page.ClientScript.RegisterStartupScript(this.GetType(), "OnUnload", "GUnload();", true);

In Javascript:
function AddOnLoadFunctionParam(func, containerId) {
$addHandler(window, "load", function() { func(containerId) });
function AddOnUnloadFunction(func) {
$addHandler(window, "unload", func);
function initialize(id) {
var map = new google.maps.Map2(document.getElementById(id));
map.setCenter(new google.maps.LatLng(37.4419, -122.1419), 13);
//do what you need to do.

I pass the div’s Id to the javascript by using the registering it to the page. In that javascript function.
I am using ASP.NET AJAX Client Library function (although nothing AJAX here), to append it as an onload event handler.
This will preserve all other onload event handler. Do the same to onunload with GUnload().

Try it, and write to me if you get any question. Since I have done this quite a while ago.
And write this by memory, and I know my memory is not that good.


Abort Operation in IE under ASP.NET+JavaScript

My colleague develop a page using ASP.NET and some javascript. Specifically say, that is a google map API page.

It runs okay under his local development environment but throw a Abort Operation error from IE when I test his page in a real situation remote environment.

The cause is he add some controls dynamically in code-behind and then use GetElementByID() in his javascript. and he invokes his javascript too early.

If you encounter this problem, you can try to postpone your GetElementByID().