Question

我有这个问题，我有4个变量用GPS坐标初始化，一旦加载，我必须在另一个脚本。前两个是立即加载，另外两个是4秒后加载，如下所示：

take 6 xs
 = take 6 xs where xs=1:next xs                   -- next looks 1 element back
 = 1:take 5 xs1 where xs=1:xs1; xs1=next xs
 = 1:take 5 xs1 where xs1=2:10:next xs1                -- 2 elements back
 = 1:2:take 4 xs2 where xs1=2:xs2; xs2=10:next xs1
 = 1:2:10:take 3 xs3 where xs1=2:xs2; xs2=10:xs3; xs3=next xs1
 = 1:2:10:take 3 xs3 where xs2=10:xs3; xs3=3:20:next xs2       -- 3 elements 
 = 1:2:10:3:take 2 xs4 where xs2=10:xs3; xs3=3:xs4; xs4=20:next xs2
 = 1:2:10:3:20:take 1 xs5 where xs2=10:xs3; xs3=3:xs4; xs4=20:xs5; xs5=next xs2
 = 1:2:10:3:20:take 1 xs5 where xs3=3:xs4; xs4=20:xs5; xs5=11:100:next xs3     -- 4 
 ....

如果您知道如何创建条件＆＃39;如果＆＃39;这样做（例如：当所有坐标变量都初始化时，执行此操作）？因为GPS总是加载不同的时间而且速度很慢感谢。

某事，我试过

(function(){
        function onSuccess(position) {

         poslat = position.coords.latitude;                   
         poslon = position.coords.longitude;                  

        console.log('latitudine1 ' + poslat);
        console.log('longitudine1 ' + poslon);

        //after 4 second

        setTimeout(function(){

         poslt = position.coords.latitude;                    
         posln = position.coords.longitude;                    
         speed = position.coords.speed;
         alt = position.coords.altitudeAccuracy;
         precisione = position.coords.accuracy;
         document.getElementById("altitudine").innerHTML = alt;
         document.getElementById("precision").innerHTML = precisione;
         var speedfix = speed * 3.6;
         var speedfixed = speedfix.toFixed(3);
         document.getElementById("sped").innerHTML = speedfixed;

        console.log('latitudine2 ' + poslt);
        console.log('longitudine2 ' + posln);
        //alert("Passed 4 second");
         },4000);

Answer 1

此代码适用于wi-fi / 3g连接。

 if ((poslat != null) && (poslon != null) && (poslt != null) && (posln != null))
           {
             ready();
           }else{
           alert('GPS / Connessione debole.. ')

           }

但是当我尝试只使用GPS（没有信号）时不起作用。为什么？我认为当GPS加载时，变量没有值“null” 但是哪个??

＆＃39; IF＆＃39;只有在初始化时才启动变量的条件

1 个答案: