在easyUI的基础组件中combobox只有带radiobutton的效果，而且只支持单选。
但是我们可以在此控件的基础上，对combobox进行重写，就能够实现checkbox多选效果。
大致需要重写以下几个方法：
format : function(row){
var opts = $(this).combobox("options");
return "<input type=‘checkbox‘ class=‘combobox-checkbox‘>" + row[opts.textField];
}
onShowPanel : function(){
var opts = $(this).combobox("options");
target = this;
var values = $(target).combobox("getValues");
$.map(values, function(value){
var children = $(target).combobox("panel").children();
$.each(children, function(index, obj){
if(value == obj.getAttribute("value") && obj.children && obj.children.length > 0){
obj.children[0].checked = true;
} }); }); }
onLoadSuccess : function(){
var opts = $(this).combobox("options");
var target = this;
var values = $(target).combobox("getValues");
$.map(values, function(value){
var children = $(target).combobox("panel").children();
$.each(children, function(index, obj){
if(value == obj.getAttribute("value") && obj.children && obj.children.length > 0){
obj.children[0].checked = true;
} }); }); }
onSelect : function(row){
var opts = $(this).combobox("options");
var objCom = null;
var children = $(this).combobox("panel").children();
$.each(children, function(index, obj){
if(row[opts.valueField] == obj.getAttribute("value")){
objCom = obj;
}
});
if(objCom != null && objCom.children && objCom.children.length > 0){
objCom.children[0].checked = true;
}
}
onUnselect : function(row){
var opts = $(this).combobox("options");
var objCom = null;
var children = $(this).combobox("panel").children();
$.each(children, function(index, obj){
if(row[opts.valueField] == obj.getAttribute("value")){
objCom = obj;
}
});
if(objCom != null && objCom.children && objCom.children.length > 0){
objCom.children[0].checked = false;
}
}
关于easyUI中combobox多选并附加checkbox的实现
原文：http://my.oschina.net/u/2487836/blog/517845