用js閉包的方法實現(xiàn)多點標注冒泡示例
更新時間:2014年05月29日 15:29:13 作者:
這篇文章主要介紹了用js閉包的方法實現(xiàn)多點標注冒泡,需要的朋友可以參考下
這兩天在做地圖這塊,一點點js代碼,各種坑。第一次接觸js,各種難,下面就這幾天的研究做一些總結(jié),求坑
在事件監(jiān)聽器中使用閉包
在執(zhí)行事件監(jiān)聽器時,通常可取的做法是將私有數(shù)據(jù)和持久性數(shù)據(jù)附加到對象中。JavaScript 不支持“私有”實例數(shù)據(jù),但是支持允許內(nèi)部函數(shù)訪問外部變量的閉包。在事件監(jiān)聽器中,閉包非常適用于訪問通常不附加到發(fā)生事件的對象的變量。
以下示例在事件監(jiān)聽器中使用了函數(shù)閉包將加密訊息分配給一組標記。點擊每個標記將會看到加密訊息的一部分,該訊息并不包含在標記本身內(nèi)。
var map;
function initialize() {
var myLatlng = new google.maps.LatLng(-25.363882,131.044922);
var mapOptions = {
zoom: 4,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
// Add 5 markers to the map at random locations.
var southWest = new google.maps.LatLng(-31.203405,125.244141);
var northEast = new google.maps.LatLng(-25.363882,131.044922);
var bounds = new google.maps.LatLngBounds(southWest,northEast);
map.fitBounds(bounds);
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
for (var i = 0; i < 5; i++) {
var location = new google.maps.LatLng(southWest.lat() + latSpan * Math.random(),
southWest.lng() + lngSpan * Math.random());
var marker = new google.maps.Marker({
position: location,
map: map
});
var j = i + 1;
marker.setTitle(j.toString());
attachSecretMessage(marker, i);
}
}
// The five markers show a secret message when clicked
// but that message is not within the marker's instance data.
function attachSecretMessage(marker, number) {
var message = ["This","is","the","secret","message"];
var infowindow = new google.maps.InfoWindow(
{ content: message[number],
size: new google.maps.Size(50,50)
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map,marker);
});
}
這段代碼是從google官方里面復制下來的
接下來我要實現(xiàn)從數(shù)據(jù)庫中讀取經(jīng)緯度、地址信息,在google map上進行標注并單擊標注出現(xiàn)信息
要實現(xiàn)多點標注,以上代碼可以參考
<script type="text/javascript" >
var map;
window.onload =function load() {
var number='<%=number %>';//獲取后臺cs的pubilc的number的值
var address = new Array()
var weidu=new Array();
var jingdu=new Array();
var chepai = new Array();
<% for(int i=0;i<number;i++){ %>
weidu.push('<%=lan[i]%>');//從后臺cs獲取經(jīng)緯度的值
jingdu.push('<%=lon[i]%>');
address.push('<%=addr[i]%>');
chepai.push('<%=carnum[i] %>');
// var wei ;
// wei = chepai['<%=i%>'];
// alert(wei);
<% } %>
var Latlng = new google.maps.LatLng(weidu[0], jingdu[0]);
// var myLatlng = new google.maps.LatLng(25.273566, 110.290195);
var myOptions = {
zoom: 8,
center: Latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);////初始化一個地圖實例
for(var j=0;j<number;j++) //這里卡了好久,原因是js的類型只有var;把js和cs弄混了一直用到《% %>,其實單純的js不需要,跟C差不多就可以了
{
var lat = weidu[j];
var lng = jingdu[j];
var addre = address[j];
var chepaihao = chepai[j];
// alert(j);
// alert(lat);
// var image = 'Image/webcam.png';
//設(shè)置標志點
var myLatlng = new google.maps.LatLng(weidu[j ], jingdu[j ]);
var h = chepaihao;
var tit = h.toString();
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
// icon: "http://google-maps-icons.googlecode.com/files/yellow08.png",
// icon: image, //通過icon可以設(shè)定自己想顯示的圖標,不設(shè)置則顯示Google map默認的圖標
title: tit //title表示鼠標放到marker上要顯示的值。
});
attachSecretMessage(marker, j,addre,lat,lng);
}
}
function attachSecretMessage(marker, number,addre1,lat1,lng1) {
// var message = ["This", "is", "the", "secret", "message"];
var infowindow = new google.maps.InfoWindow(
{ content: "<span style='font-size:15px'><b>地址: </b>" + addre1 + "<br>"+ "經(jīng)緯度:"+ lat1 + ","+ lng1 +"</span>",
size: new google.maps.Size(50, 50)
});
// infowindow.setContent("地址:"+ addre1 +"經(jīng)度:" +lat1 + "緯度:"+lng1);
//點擊彈出信息窗口
google.maps.event.addListener(marker, 'click', function () {
infowindow.open(map, marker);
});
}
</script>
cs后端代碼:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class Default2 : System.Web.UI.Page
{
public double[] la = new double[25];
public double[] ln = new double[25];
public int[] id = new int[25];
public string[] addr = new string[25];
public int number;
protected void Page_Load(object sender, EventArgs e)
{
string mycnnConnectionString1 = System.Configuration.ConfigurationManager.ConnectionStrings["testconect"].ConnectionString; //創(chuàng)建連接字符串
SqlConnection mycnn1 = new SqlConnection(mycnnConnectionString1);
mycnn1.Open();
SqlCommand cmd1 = new SqlCommand("select L_ID,L_Lantitude,L_Longitude,L_Address from LatestPosition ", mycnn1);
SqlDataReader dr1 = cmd1.ExecuteReader();
int k2 = 0;
int k3 = 0;
int k4 = 0;
int k1 = 0;
// string buf1 = "";
double buf2 = 0;
double buf3 = 0;
int buf4 = 0;
string buf1 = "0";
while (dr1.Read())
{
//lat
buf2 = (double)dr1["L_Lantitude"];
la[k2] = buf2;
k2++;
//lng
buf3 = (double)dr1["L_Longitude"];///數(shù)據(jù)庫讀取float型的數(shù)據(jù)要用double
ln[k3] = buf3;
k3++;
//id
buf4 = (int)dr1["L_ID"];
id[k4] = buf4;
k4++;
buf1 = dr1["L_Address"].ToString();
addr[k1] = buf1;
k1++;
}
number = k4;
dr1.Close();
mycnn1.Close();
}
}
在事件監(jiān)聽器中使用閉包
在執(zhí)行事件監(jiān)聽器時,通常可取的做法是將私有數(shù)據(jù)和持久性數(shù)據(jù)附加到對象中。JavaScript 不支持“私有”實例數(shù)據(jù),但是支持允許內(nèi)部函數(shù)訪問外部變量的閉包。在事件監(jiān)聽器中,閉包非常適用于訪問通常不附加到發(fā)生事件的對象的變量。
以下示例在事件監(jiān)聽器中使用了函數(shù)閉包將加密訊息分配給一組標記。點擊每個標記將會看到加密訊息的一部分,該訊息并不包含在標記本身內(nèi)。
復制代碼 代碼如下:
var map;
function initialize() {
var myLatlng = new google.maps.LatLng(-25.363882,131.044922);
var mapOptions = {
zoom: 4,
center: myLatlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
// Add 5 markers to the map at random locations.
var southWest = new google.maps.LatLng(-31.203405,125.244141);
var northEast = new google.maps.LatLng(-25.363882,131.044922);
var bounds = new google.maps.LatLngBounds(southWest,northEast);
map.fitBounds(bounds);
var lngSpan = northEast.lng() - southWest.lng();
var latSpan = northEast.lat() - southWest.lat();
for (var i = 0; i < 5; i++) {
var location = new google.maps.LatLng(southWest.lat() + latSpan * Math.random(),
southWest.lng() + lngSpan * Math.random());
var marker = new google.maps.Marker({
position: location,
map: map
});
var j = i + 1;
marker.setTitle(j.toString());
attachSecretMessage(marker, i);
}
}
// The five markers show a secret message when clicked
// but that message is not within the marker's instance data.
function attachSecretMessage(marker, number) {
var message = ["This","is","the","secret","message"];
var infowindow = new google.maps.InfoWindow(
{ content: message[number],
size: new google.maps.Size(50,50)
});
google.maps.event.addListener(marker, 'click', function() {
infowindow.open(map,marker);
});
}
這段代碼是從google官方里面復制下來的
接下來我要實現(xiàn)從數(shù)據(jù)庫中讀取經(jīng)緯度、地址信息,在google map上進行標注并單擊標注出現(xiàn)信息
要實現(xiàn)多點標注,以上代碼可以參考
復制代碼 代碼如下:
<script type="text/javascript" >
var map;
window.onload =function load() {
var number='<%=number %>';//獲取后臺cs的pubilc的number的值
var address = new Array()
var weidu=new Array();
var jingdu=new Array();
var chepai = new Array();
<% for(int i=0;i<number;i++){ %>
weidu.push('<%=lan[i]%>');//從后臺cs獲取經(jīng)緯度的值
jingdu.push('<%=lon[i]%>');
address.push('<%=addr[i]%>');
chepai.push('<%=carnum[i] %>');
// var wei ;
// wei = chepai['<%=i%>'];
// alert(wei);
<% } %>
var Latlng = new google.maps.LatLng(weidu[0], jingdu[0]);
// var myLatlng = new google.maps.LatLng(25.273566, 110.290195);
var myOptions = {
zoom: 8,
center: Latlng,
mapTypeId: google.maps.MapTypeId.ROADMAP
};
map = new google.maps.Map(document.getElementById("map_canvas"), myOptions);////初始化一個地圖實例
for(var j=0;j<number;j++) //這里卡了好久,原因是js的類型只有var;把js和cs弄混了一直用到《% %>,其實單純的js不需要,跟C差不多就可以了
{
var lat = weidu[j];
var lng = jingdu[j];
var addre = address[j];
var chepaihao = chepai[j];
// alert(j);
// alert(lat);
// var image = 'Image/webcam.png';
//設(shè)置標志點
var myLatlng = new google.maps.LatLng(weidu[j ], jingdu[j ]);
var h = chepaihao;
var tit = h.toString();
var marker = new google.maps.Marker({
position: myLatlng,
map: map,
// icon: "http://google-maps-icons.googlecode.com/files/yellow08.png",
// icon: image, //通過icon可以設(shè)定自己想顯示的圖標,不設(shè)置則顯示Google map默認的圖標
title: tit //title表示鼠標放到marker上要顯示的值。
});
attachSecretMessage(marker, j,addre,lat,lng);
}
}
function attachSecretMessage(marker, number,addre1,lat1,lng1) {
// var message = ["This", "is", "the", "secret", "message"];
var infowindow = new google.maps.InfoWindow(
{ content: "<span style='font-size:15px'><b>地址: </b>" + addre1 + "<br>"+ "經(jīng)緯度:"+ lat1 + ","+ lng1 +"</span>",
size: new google.maps.Size(50, 50)
});
// infowindow.setContent("地址:"+ addre1 +"經(jīng)度:" +lat1 + "緯度:"+lng1);
//點擊彈出信息窗口
google.maps.event.addListener(marker, 'click', function () {
infowindow.open(map, marker);
});
}
</script>
cs后端代碼:
復制代碼 代碼如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
public partial class Default2 : System.Web.UI.Page
{
public double[] la = new double[25];
public double[] ln = new double[25];
public int[] id = new int[25];
public string[] addr = new string[25];
public int number;
protected void Page_Load(object sender, EventArgs e)
{
string mycnnConnectionString1 = System.Configuration.ConfigurationManager.ConnectionStrings["testconect"].ConnectionString; //創(chuàng)建連接字符串
SqlConnection mycnn1 = new SqlConnection(mycnnConnectionString1);
mycnn1.Open();
SqlCommand cmd1 = new SqlCommand("select L_ID,L_Lantitude,L_Longitude,L_Address from LatestPosition ", mycnn1);
SqlDataReader dr1 = cmd1.ExecuteReader();
int k2 = 0;
int k3 = 0;
int k4 = 0;
int k1 = 0;
// string buf1 = "";
double buf2 = 0;
double buf3 = 0;
int buf4 = 0;
string buf1 = "0";
while (dr1.Read())
{
//lat
buf2 = (double)dr1["L_Lantitude"];
la[k2] = buf2;
k2++;
//lng
buf3 = (double)dr1["L_Longitude"];///數(shù)據(jù)庫讀取float型的數(shù)據(jù)要用double
ln[k3] = buf3;
k3++;
//id
buf4 = (int)dr1["L_ID"];
id[k4] = buf4;
k4++;
buf1 = dr1["L_Address"].ToString();
addr[k1] = buf1;
k1++;
}
number = k4;
dr1.Close();
mycnn1.Close();
}
}
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