RadioButtonList和Label不在同一行

The new line is not due to the label control. By default the RadioButtonList is rendered as a HTML table and this forces the Radiobuttonlist to be rendered on a separate line. There are two ways to solve your problem

1. Change the RepeatLayout of your Radiobuttonlist by setting RepeatLayout="Flow" as given below

 

<asp:RadioButtonList repeatdirection="Horizontal" ID="RadioButtonList1" runat="server" RepeatLayout="flow" >
  

2. If you prefer the Table layout, then the workaround is to enclose your label and Radiobuttonlist within a single <tr> tag like given below. This will force the label and radionbuttonlist to be on the same line

 

<table>
<tr>
<td>
    <asp:Label ID="PaymentLabel" Text="Payment Option:" runat="server" ></asp:Label>
</td>
<td>
    <asp:RadioButtonList repeatdirection="Horizontal" ID="RadioButtonList1" runat="server">
    <asp:ListItem Selected="True">Cash</asp:ListItem>
    <asp:ListItem>Credit Card</asp:ListItem>
    </asp:RadioButtonList>
</td>
</tr>
</table>