个人实现翻页及store加载完事件

    var limit = 2;
    if (grid_alert.getStore().getAt(0).data != null) {
     var record = grid_alert.getStore().getAt(0);
     grid_alert.getBottomToolbar().add([{
      text : '上一页',
      handler : function() {
       if (grid_alert.getStore()) {
        record = grid_alert.getStore().getAt(0);
        var page = (record.data.page - 1) < 1
          ? 1
          : (record.data.page - 1);
        // 重新加载数据。不过其中的页码变了
        grid_alert.store.load({
         params : {
          json : Ext.encode({
             Action : {
              Code : 30311
             },
             page : page,
             limit : limit,
             DBID : (Ext
               .getCmp('chooseDB')
               .getValue() == null || Ext
               .getCmp('chooseDB')
               .getValue() == "")
               ? 0
               : Ext
                 .getCmp('chooseDB')
                 .getValue()
            })
         }
        });
        grid_alert.getBottomToolbar().items.items[2]
          .setDisabled(false);
        grid_alert.getBottomToolbar().items
          .last()
          .setText((page)
            + "/"
            + (Math
              .floor((record.data.Total + 1)
                / limit)));
       }
       if (record.data.page == 2) {
        grid_alert.getBottomToolbar().items.items[1]
          .setDisabled(true);
       }
       grid_alert.doLayout();
      }
     }, {
      text : '下一页',
      handler : function() {
       if (grid_alert.getStore()) {
        record = grid_alert.getStore().getAt(0);
        var page = (record.data.page + 1) > (Math
          .floor(record.data.total / limit) + 1)
          ? (Math.floor(record.data.Total / limit
            + 1))
          : record.data.page + 1;
        // 重新加载数据。不过其中的页码变了
        grid_alert.store.load({
         params : {
          json : Ext.encode({
             Action : {
              Code : 30311
             },
             page : page,
             limit : limit,
             DBID : (Ext
               .getCmp('chooseDB')
               .getValue() == null || Ext
               .getCmp('chooseDB')
               .getValue() == "")
               ? 0
               : Ext
                 .getCmp('chooseDB')
                 .getValue()
            })
         }
        });
        grid_alert.getBottomToolbar().items.items[1]
          .setDisabled(false);
        grid_alert.getBottomToolbar().items
          .last()
          .setText((page)
            + "/"
            + (Math
              .floor((record.data.Total + 1)
                / limit)));
       }
       if (record.data.Total % 2 == 0) {
        if (record.data.page == (Math
          .floor((record.data.Total) / limit) - 1)) {
         grid_alert.getBottomToolbar().items.items[2]
           .setDisabled(true);
        }
       } else {
        if (record.data.page == (Math
          .floor((record.data.Total + 1) / limit) - 1)) {
         grid_alert.getBottomToolbar().items.items[2]
           .setDisabled(true);
        }
       }
       grid_alert.doLayout();
      }
     }, {
      xtype : 'label',
      html : 1 + "/"
        + (Math.floor((record.data.Total + 1) / limit))
     }]);
     grid_alert.doLayout();
    }
    // }