在用 extjs editorgridpanel 进行输入编辑的时候, 默认情况下只支持使用 tab 键可以实现焦点切换, 如果想让editorgridpanel 在编辑时通过方向键来实现焦点跳转切换，只需加上以下代码：

//让grid支持方向键盘 by liongis@163.comExt.override(Ext.grid.CellSelectionModel, {    onEditorKey : function(field, e) {        var smodel = this;        var k = e.getKey(), newCell, g = smodel.grid, ed = g.activeEditor;        switch(k){            case e.TAB:                 e.stopEvent();                 ed.completeEdit();                 if (e.shiftKey) {                     newCell = g.walkCells(ed.row, ed.col-1, -1, smodel.acceptsNav, smodel);                 } else {                     newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);                 }                 if (ed.col == 1) {                     if (e.shiftKey) {                         newCell = g.walkCells(ed.row, ed.col+1, -1, smodel.acceptsNav, smodel);                     } else {                         newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);                     }                 }                break;            case e.UP:                 e.stopEvent();                 ed.completeEdit();                 newCell = g.walkCells(ed.row-1, ed.col, -1, smodel.acceptsNav, smodel);                break;            case e.DOWN:                 e.stopEvent();                 ed.completeEdit();                 newCell = g.walkCells(ed.row+1, ed.col, 1, smodel.acceptsNav, smodel);                break;            case e.LEFT:                 e.stopEvent();                 ed.completeEdit();                 newCell = g.walkCells(ed.row, ed.col-1, -1, smodel.acceptsNav, smodel);                 break;             case e.RIGHT:                 e.stopEvent();                 ed.completeEdit();                 newCell = g.walkCells(ed.row, ed.col+1, 1, smodel.acceptsNav, smodel);                   break;        }       if (newCell) {            g.startEditing(newCell[0], newCell[1]);       }     }});

注意：这里重写的是：CellSelectionModel ，而不是RowSelectionModel