多选框实现单选，取消全选，取消选中

<el-table  ref="tables" 
	:data="tableData.slice((currentPage-1)*pageSize,currentPage*pageSize)" border size="mini"
	:header-cell-style="{'text-align':'center'}" :height="tableHeight"
	:header-cell-class-name="cellnames"
	@row-click="showRows">
	
	<el-table-column fixed align="center" 
	type="selection" width=