How to put the option to check all the Checkboxes in the JQGrid

I was able to do this quite simply using multiselect: true,

var grid = $("#jqGrid").jqGrid({
        url: '/Expedicao/Minuta/CarregaTransportadorNotas',
        datatype: 'json',
        mtype: 'GET',  
        postData: {
                    transportador: function () { return jQuery("#transportador").val(); }
        }, 
        colModel: [          
                    { label: 'Codigo', name:'doc', width:50 },         
                    { label: 'Série', name:'serie', width:50 },                     
                 ],

                loadonce: true,
                viewrecords: true,
                width: 780,
                height: 200,
                rowNum: 20,
                rowList : [20,30,50],
                rownumbers: true, 
                rownumWidth: 25, 
                multiselect: true,
                pager: "#jqGridPager"

    });



$("#jqGrid").jqGrid('navGrid', 'jqGridPager', { edit: false, add: false, del: false })

Create a <input type="checkbox" id="selAll"> Selecionar tudo off the table (you can put it above the table. You can format it any way you want):

<input type="checkbox" id="selAll"> Selecionar tudo
<br>
<table id="jqGrid"></table>
<div id="jqGridPager"></div>

It will look something like this:

Andentertwoeventsinthescripttogettheclicksonthe%softhe%sthatwillcontrol,capturingthe%softhetablebythecheckboxclass,whichistheclassgeneratedbytheplugin:

$(":checkbox", "table.ui-jqgrid-htable").click(function(){

   if(!$(this).is(":checked")) $("#selAll").prop("checked", false);

   var cbs = $(":checkbox", "table.ui-jqgrid-htable");
   var allchkd = true;

   for(var x=0; x<cbs.length; x++){
      if(!$(cbs[x]).is(":checked")){
         allchkd = false;
         break;
      }
   }

   if(allchkd) $("#selAll").prop("checked", true );

});

$("#selAll").click(function(){
   var boxes = $(":checkbox", "table.ui-jqgrid-htable"); // pega os checkboxes da tabela
   boxes.prop("checked", $(this).is(":checked"));
});