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我使用 Google Places API 来显示各个地方。我想一次显示 20 个位置，当用户滚动表格视图并到达最后一个字段时，我想添加其余数据等等。我创建了一个函数，它返回视图并完美地排除一件事。当没有更多数据可用时，它会继续加载已加载的最后一个数据。这是我的代码。

Ti.include('Functions/get_lat_long.js');
var myTable = Ti.UI.createTableView();
var next_page;
var nxt_pge_tkn;
var tableData = [];
function json_parsing(url,firsttime,winloading)
{

var view1=Ti.UI.createView({
        //height : '100%',
        width : '100%',
        backgroundColor : '#EDDA74',
        top : '10%',
        borderColor : "black"
    });
//For storing url in case next_page_token variable is invalid

var curloc=Ti.App.Properties.getString("curlocation");
//calling method in order to retrive latitude and longitude of current location
get_latitude_longitude(curloc);
//setting the base url that have been initialized in global.js file
var baseurl=Ti.App.Properties.getString("preurl");
//storing lat and lng file that have been initialized in get_lat_lon.js file get_latitude_longitude function 
var lat=Ti.App.Properties.getString("curlat");
var lng=Ti.App.Properties.getString("curlng");
//Storing radius which have been initialized in global.js file
var radiusmts=Ti.App.Properties.getInt("curradius")*1000;
//setting location type from the value that have been selected in app.js file by user
var loc_type=Ti.App.Properties.getString("curcategory");
//fetching and storing key which have been initialized in global.js file
var key=Ti.App.Properties.getString("apikey");
if(firsttime==true)
{
    winloading.open();
    var completeurl=baseurl+lat+","+lng+"&radius=" + radiusmts+ "&types=" + loc_type+ "&sensor=false&key=" + key;
}
else
{
    winloading.show();
    var completeurl=url;
}


var client = Ti.Network.createHTTPClient();


Ti.API.info("complete url " +completeurl);
client.open('GET',completeurl);
client.onload = function(e) {
       //For getting next_page_token so that next page results could be displayed
      var json = JSON.parse(this.responseText);

      if(json.next_page_token)
      {
        Ti.API.info("Next page token found ");
        next_page=true;
        nxt_pge_tkn=json.next_page_token;
      }
      else
      {     
        Ti.API.info("Next page token not found ");
        next_page=false;
      }

      if(json.results.length==0)
      {
        var lblno_record=Titanium.UI.createLabel({
            text : "No Record Found",
            color : "black",
            font : {fontSize : "25%" }
        });
      view1.add(lblno_record);
      }
      else
      {
      for(var i=0; i <json.results.length;i++) 
            {
            //Ti.API.info("Place " + json.results[i].name+ " Lat " + json.results[i].geometry.location.lat + " Lng " + json.results[i].geometry.location.lng);
            var row = Ti.UI.createTableViewRow({
                className : "row"
                //height : "80%"
                });
            //For temporary storing name in name variable
            var name=json.results[i].name;
            //Logic for shortening string in order to avoid overlapping of string
            (name.length>35)?name=name.substr(0,34)+ "..." :name=name;
            //Create label for displaying the name of place
            var lblname=Ti.UI.createLabel({
                //text : json.results[i].name,
                text :  name,
                color : "black",
                font : {fontSize : "20%"},
                left : "22%",
                top : "5%"
                });
             Ti.API.info("Name :- " + name);
            row.add(lblname);

            var add= json.results[i].vicinity;
            (add.length>125) ? add=add.substr(0,123)+ ". ." : add=add;

            var lbladdress=Ti.UI.createLabel({
                text : add,
                color : "black",
                font : {fontSize : "15%"},
                left : "22%",
                top : "30%",
                width : "71%"
                });
            row.add(lbladdress);

            var imgico=Ti.UI.createImageView({
                image : json.results[i].icon,
                height : "90",
                width : "90",
                left : "1%",
                top : "3%"
                //bottom : "10%"
                });
            row.add(imgico);      
            tableData.push(row);
            }
            //setting data that have been set to mytable view
            myTable.setData(tableData);
            view1.add(myTable);

            }
    winloading.hide();
};
client.onerror=function(e){
    alert("Network Not Avaliable");
};

myTable.addEventListener('scroll',function(e){
            var first=e.firstVisibleItem;
            var visible=e.visibleItemCount;
            var total=e.totalItemCount;
            Ti.API.info("Value of next_page_token before loop " + next_page);
            if(next_page==true &&  first+visible==total )
            {
                Ti.API.info("Value of next_page_token in loop " + next_page);
                var newurl="https://maps.googleapis.com/maps/api/place/nearbysearch/json?pagetoken="+nxt_pge_tkn+"&sensor=false&key="+key;
                firsttime=false;
                winloading.show();
                //myTable.removeEventListener('scroll',function(e){});
                json_parsing(newurl,firsttime,winloading);
                //get_next_page(newurl);
            }
        });



client.send();
return view1;
client.clearCookies();
}
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1 回答 1

0

我正在查看您的代码，我想指出：

  • 块有一个重要问题：

    myTable.addEventListener('scroll',function(e){

...

});

    每次调用 json_parsing 函数时都会调用此块。因此，您将有几个附加到 myTable 滚动事件的函数。我敢肯定这不是你的本意。你应该把它放在 json_parsing 之外。

  • 关于您的具体问题，您可以尝试查看 client.onload 函数中的 json.next_page_token 值：

    client.onload = function(e) {
//For getting next_page_token so that next page results could be displayed
var json = JSON.parse(this.responseText);
Ti.API.info(JSON.stringify(this.responseText);
if(json.next_page_token)
{
...

    也许该值是一个空对象 {} 或将返回一个真实值的“假”字符串。不要忘记，在 javascript 中只有 6 个虚假值：false、undefined、null、0、'' 和 NaN。

  • 实际上这是一个小问题，但在文档中HTTPClient.onload和 HTTPClient.onerror 函数必须在调用 HTTPClient.open 函数之前设置

  • 顺便说一句，你的 json_parsing 函数末尾有无法访问的代码，但我想你已经知道了:-)

    client.send();
return view1;
client.clearCookies(); //Unreachable code
于 2013-11-26T11:09:07.290 回答