er.value = number 这句有什么 用?以下为googl maps 的示例代码:
var map = new GMap2(document.getElementById("map_canvas"));
map.setCenter(new GLatLng(39.9493, 116.3975), 13);
// Creates a er at the given point
// The five ers show a secret message when clicked
// but that message is not within the er's instance data
function createMarker(point, number) {
var er = new GMarker(point);
var message = ["这","是","个","秘密","消息"];
er.value = number;
GEvent.addListener(er, "click", function() {
var myHtml = "<b>#" + number + "</b><br/>" + message[number -1];
map.openInfoWindowHtml(point, myHtml);
});
return er;
}
// Add 5 ers to the map at random locations
var bounds = map.getBounds();
var southWest = bounds.getSouthWest();
var northEast = bounds.getNorthEast();
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
for (var i = 0; i < 5; i++) {
var point = new GLatLng(southWest.lat() + latSpan * Math.random(),
southWest.lng() + lngSpan * Math.random());
map.addOverlay(createMarker(point, i + 1));
}
var map = new GMap2(document.getElementById("map_canvas"));
map.setCenter(new GLatLng(39.9493, 116.3975), 13);
// Creates a er at the given point
// The five ers show a secret message when clicked
// but that message is not within the er's instance data
function createMarker(point, number) {
var er = new GMarker(point);
var message = ["这","是","个","秘密","消息"];
er.value = number;
GEvent.addListener(er, "click", function() {
var myHtml = "<b>#" + number + "</b><br/>" + message[number -1];
map.openInfoWindowHtml(point, myHtml);
});
return er;
}
// Add 5 ers to the map at random locations
var bounds = map.getBounds();
var southWest = bounds.getSouthWest();
var northEast = bounds.getNorthEast();
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
for (var i = 0; i < 5; i++) {
var point = new GLatLng(southWest.lat() + latSpan * Math.random(),
southWest.lng() + lngSpan * Math.random());
map.addOverlay(createMarker(point, i + 1));
}
GEvent.addListener
的实现了.
GEvent.addListener(er, "click", function() {
var myHtml = " <b>#" + number + " </b> <br/>" + message[number -1];
map.openInfoWindowHtml(point, myHtml);
});
//以上两句,我看不出有什么联系来,请指教
能把里面的东东打出来或者可以解释.