方法一属性
<asp:CheckBoxList ID="CheckBoxList1" runat="server" RepeatDirection="Horizontal">
</asp:CheckBoxList>
//可选水平或竖直
方法二点击选择
点击CheckBox时,排列方式为水平
protected void CheckBox1_CheckedChanged(object sender, EventArgs e)
{
this.CheckBoxList1.RepeatDirection = RepeatDirection.Horizontal;
this.CheckBoxList1.RepeatColumns = 3; //每行的个数
}