var sayHi = function(name){
    alert('Hi, ' + name);
}

// executes immediately:
sayHi('Fred');

// executes after 2 seconds:
Ext.defer(sayHi, 2000, this, ['Fred']);

// this syntax is sometimes useful for deferring
// execution of an anonymous function:
Ext.defer(function(){
    alert('Anonymous');
}, 100);
//下面是Ext中定时运行任务
 //每隔5分钟定时任务
        var updateMsg = function(){
           alert('每隔五分钟我就要出现!');
        }
        var task = {
            run: updateMsg,
            interval: 300000 //300 second
        }
        var runner = new Ext.util.TaskRunner();
        runner.start(task);

------解决方案--------------------
Ext.util.DelayedTask 可以用这两个

  Ext.util.DelayedTask类从名字上就可以看出它是推迟任务管理

参考这个地方