我编写了以下代码,它获得了lbllat和lbllon的完美价值:
<asp:UpdatePanel ID="updatepanel_vehicleinfo" runat="server" OnLoad="updatepanel_vehicleinfo_Load">
<ContentTemplate>
<asp:Repeater ID="vehicle_info" runat="server">
<ItemTemplate>
<asp:Label ID="lbllat" runat="server" Text='<%#Eval("lat") %>'></asp:Label><br />
<asp:Label ID="lbllon" runat="server" Text='<%#Eval("lon") %>'></asp:Label><br />
</ItemTemplate>
</asp:Repeater>
<script type="text/javascript" src="http://maps.googleapis.com/maps/api/js?sensor=false"></script>
<script type="text/javascript">
function initialize() {
var lat = document.getElementById('<%=lbllat.ClientID %>').value;
var lon = document.getElementById('<%=lbllon.ClientID %>').value;
var myLatlng = new google.maps.LatLng(lat, lon)
var mapOptions = {
center: myLatlng,
zoom: 6,
mapTypeId: google.maps.MapTypeId.ROADMAP,
marker: true
};
var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
var marker = new google.maps.Marker({
position: myLatlng
});
marker.setMap(map);
}
</script>
</ContentTemplate>
</asp:UpdatePanel>
<br />
<div id="map_canvas" style="width: 500px; height: 500px">
</div>
现在当我从代码隐藏中调用javascript函数时,如下所示:
DataSet dsvehicle_info = new DataSet();
dsvehicle_info = cls.ReturnDataSet("RetriveData_Alias1",
new SqlParameter("@Field", "lat,lon"),
new SqlParameter("@TblNm", "current_gps_data left join device_master on device_master.id=current_gps_data.id"),
new SqlParameter("@WhereClause", "where current_gps_data .id=24"));
vehicle_info.DataSource = dsvehicle_info;
vehicle_info.DataBind();
ScriptManager.RegisterStartupScript(this, this.GetType(), "Javascript", "javascript:initialize();", true);
它提供了lat和lot的完美答案,并且它也在转发器中打印,但是当我调用javascript时,lat and lon
值设置为null
那么如何才能在javascript中获得正确的lat和lon值?
答案 0 :(得分:2)
</ContentTemplate>
Lat: <asp:Label ID="lat" runat="server"></asp:Label><br />
Lon: <asp:Label ID="lon" runat="server"></asp:Label><br />
</asp:UpdatePanel>
在
之前和之后放置此标签现在在你的cs文件中添加以下代码:
之后放下面的代码 vehicle_info.DataSource = dsvehicle_info;
vehicle_info.DataBind();
添加belo代码:
lat.Text = dsvehicle_info.Tables[0].Rows[0]["lat"].ToString();
lon.Text = dsvehicle_info.Tables[0].Rows[0]["lon"].ToString();
现在在javascript中更改以下两行代码:
var lat = document.getElementById('<%=lat.ClientID %>').innerHTML;
var lon = document.getElementById('<%=lon.ClientID %>').innerHTML;
现在已经完成.. !!享受!!
答案 1 :(得分:0)
您的转发器中似乎有重复的ID值。您是否尝试为每个标签指定一个类名,然后将其存储在HTML集合中?
标签控件的类似内容:
<asp:Label CssClass="lbllat" runat="server" Text='<%#Eval("lat") %>'></asp:Label><br /><asp:Label CssClass="lbllon" runat="server" Text='<%#Eval("lon") %>'></asp:Label><br />
然后在你的JS中:
var lblats = document.getElementsByClassName('lbllat');
var lbllons = document.getElementsByClassName('lbllat');
然后,lblats和lbllons HTML集合可供您通过其索引进行迭代或访问。