hideCols: function(evt, ui){
var grid = this, requireRefresh;
ui.diHide.forEach(function(di){
var col = grid.getColumn({dataIndx: di});
if(col.filter && col.filter.crules){
col.filter.crules.forEach(function(rule){
if (rule.value != undefined || rule.value2 != undefined) {
requireRefresh = true;
rule.value = rule.value2 = undefined; //clear the values while keep the filter conditions.
}
});
}
});
if( requireRefresh ) grid.filter();//refresh filter.
},