extjs获得store数据

var json = new Array();
for (var i = 0; i < storeEditFee.getCount(); i++) {
json.push(storeEditFee.getAt(i).data);
}
json = Ext.util.JSON.encode(json);
$.ajax({
type: "post",
async: false,
cache: false,
data: { "ChkExpense": json },
url: "/Manager/_Business/CheckExpense",
success: function (data, s) {

},
error: function (XMLHttpRequest, textStatus, errorThrown) {
errStr = "What‘s  wrong？";
}
});