autocomplete 绑定格式：

$( ".breakTag" ).autocomplete({
    source: init_breakTag(),
    select: function (event, ui) {
        event.preventDefault();
        $(this).val(ui.item.label);//选中文案
        breakTimeTagVal = parseInt(ui.item.value)//选中值
    },
    response: function(event,ui) {
        if((ui.content.length == 1) && (event.target.value === ui.content[0].label)){//输入完整自动补全
            ui.item = ui.content[0];
            $(this).data('ui-autocomplete')._trigger('select', 'autocompleteselect', ui);
        }
}

设置默认值：

$(input).data('ui-autocomplete')._trigger(
    'select’, 
    'autocompleteselect’, 
    {item:{value:this_value,label:this_label}}
);