How to re-config resizer's widthIncrement for one component?

[happyoliver]

At the beginning, I created a component with resizer configuration

               var newPortlet = new Ext.create('Portals.view.portal.PortletContainer', {
//                  renderTo: me.body,
//                        floating:true,
                          id: portlet.id,
                          title: moduleCfg.title,
                          x: snapBox.x,
                          y: snapBox.y,
                          icon: moduleCfg.icon,
                          moduleClass: moduleClass,
                          minWidth:moduleSize[0],
                          minHeight: moduleSize[1],
                          maxWidth: grid.width,
                          maxHeight: grid.height,
                          width: moduleSize[0],
                          height: moduleSize[1],
                          resizable: {
                            handles: 's e se',
                            widthIncrement: grid.gridW,
                            heightIncrement: grid.gridH - 2,
                            transparent: true,
                            pinned: true
                          }
  }); 

After resize window, I try to reconfig resizer's widthIncrement and heightIncrement with new value,

I try the following approach:

             module.resizable.widthIncrement = newWidth;  // not work
             module.resizer.widthIncrement = newWidth ; // not work
             module.resizable.heightIncrement = newWidth; // not work
             module.resizer.resizeTracker.widthIncrement = newWidth ; // not work 

I tried to re-create resizer with new configuration, it doesn't work, it always try to use the old widthIncrement value.

        module.resizer.destroy();
                delete module.resizer;
        module.resizer.destory();
        module.resizer =  new Ext.create('Ext.resizer.Resizer', 
                    {
                                target: module.id,
                        handles: 's e se',
                        widthIncrement: newWidth,
                        heightIncrement: newHeight,
                        transparent: true,
                        pinned: true,
                        dynamic:true

                 }); 

Can you help me to re-config resizer's widthIncrement dynamically?

Thanks in advance.