AJAX和Select出现问题

I m working with a project using an AJAX call and in my program I have a select list and I need to implement select2 but I can not do it. My code in my .js file is:

function selectAlumnos(){
   $.ajax({
        type : "GET",
        url : lang + '../../../api/select_alumnos',  //the list of data      
        dataType : "json",
        data : {
                cachehora : (new Date()).getTime()
        }
    }).done(function(response){

        var html = '';

        if(response.state == 'ok'){  //add html to the file view
           html = '<select class="select_1" name="select-allalumnos" id="select-allalumnos" onchange="getIconLocation()" >'; //class to include in select2
           html = html + '<option value="-1">...</option>';
            for(var i in response.alumnos){
                html = html + '<option value="' + response.alumnos[i].id + '" >' + response.alumnos[i].nombre + '</option>';
            } //get the list of the data
            html = html + '</select>'; // put the data in the list
        }
        $('#select-alumnos').html(html); //publish the info in the html file


    });

}

In my html page for the view I have the select-alumnos part like this:

<label for="select-alumnos" class="select">Alumno:</label>
<span id="select-alumnos"></span>  //here is the call in the AJAX

In this file (html for view) I have also put all the select2 paths to the required files, and I checked all the files are ok, also I have included the class (same class in my js file):

   $(document).ready(function() {
        $(".select_1").select2(); 
    });
</script>

What am I doing wrong because I can not get the select2 format in my list...?

you're calling select2() on .select_1 before its created. Do it after you've created the element (put it in the done function)

.done(function(response){

        var html = '';

        if(response.state == 'ok'){  //add html to the file view
           html = '<select class="select_1" name="select-allalumnos" id="select-allalumnos" onchange="getIconLocation()" >'; //class to include in select2
           html = html + '<option value="-1">...</option>';
            for(var i in response.alumnos){
                html = html + '<option value="' + response.alumnos[i].id + '" >' + response.alumnos[i].nombre + '</option>';
            } //get the list of the data
            html = html + '</select>'; // put the data in the list
        }
        $('#select-alumnos').html(html); //publish the info in the html file

        $(".select_1").select2(); 

    });