GridPanel 设置交替行背景色
tr.x-grid-row.x-grid-row-over td{
background-color: yellow;
}
tr.x-grid-row-alt.x-grid-row-over td{
background-color: red;
}
tr.x-grid-row.x-grid-row-over td{
background-color: yellow;
}
tr.x-grid-row-alt.x-grid-row-over td{
background-color: red;
}