第十五篇: Ajax Control Toolkit 控件包--4.AlwaysVisibleControlExtender


div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Panel ID="Panel1" runat="server" Width="161" Height="127" 
                    BorderColor="#C2C2C2" BorderStyle="Dashed" BorderWidth="1px">
<br />
<br />
                学习AJAX<br/>
                就去playaspx.com</asp:Panel>
<cc1:AlwaysVisibleControlExtender ID="AlwaysVisibleControlExtender1" 
                    runat="server" TargetControlID="Panel1" VerticalSide="Middle">
</cc1:AlwaysVisibleControlExtender>

<asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" 
                    onselectedindexchanged="DropDownList1_SelectedIndexChanged">
<asp:ListItem Value="None">默认</asp:ListItem>
<asp:ListItem Value="00">左上</asp:ListItem>
<asp:ListItem Value="01">左中</asp:ListItem>
<asp:ListItem Value="02">左下</asp:ListItem>
<asp:ListItem Value="10">中上</asp:ListItem>
<asp:ListItem Value="11">中中</asp:ListItem>
<asp:ListItem Value="12">中下</asp:ListItem>
<asp:ListItem Value="20">右上</asp:ListItem>
<asp:ListItem Value="21">右中</asp:ListItem>
<asp:ListItem Value="22">右下</asp:ListItem>
</asp:DropDownList>
</ContentTemplate>
</asp:UpdatePanel>


 protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
    {
switch (DropDownList1.SelectedValue[0].ToString())
        { 
case "0":
                AlwaysVisibleControlExtender1.HorizontalSide = HorizontalSide.Left;
break;
case "1":
                AlwaysVisibleControlExtender1.HorizontalSide = HorizontalSide.Center;
break;
case "2":
                AlwaysVisibleControlExtender1.HorizontalSide = HorizontalSide.Right;
break;
default:
                AlwaysVisibleControlExtender1.HorizontalSide = HorizontalSide.Center;
break;
        }
switch (DropDownList1.SelectedValue[1].ToString())
        { 
case "0":
                AlwaysVisibleControlExtender1.VerticalSide = VerticalSide.Top;
break;
case "1":
                AlwaysVisibleControlExtender1.VerticalSide = VerticalSide.Middle;
break;
case "2":
                AlwaysVisibleControlExtender1.VerticalSide = VerticalSide.Bottom;
break;
default:
                AlwaysVisibleControlExtender1.VerticalSide = VerticalSide.Middle;
break;
        }
    }

常用属性:

1、TargetControlID: 需要保持’悬浮’状态的控件ID.

2、HorizontalSide: 被控制控件的水平位置,可以为Left, Center,Right,默认值是Left.

3、HorizontalOffset: 结合上面的horizontalSide来使用,如果horizontalSide为Left,那么把HorizontalOffset设置为10px,表示距离浏览器左边10px。

4、VerticalSide: 被控制控件的垂直位置,可以为Top,Middle,Bottom。默认值是Top.

5、VertivcalOffset: 和上面的VerticalSide结合控制控件距离VerticalSide多少像素。如果VerticalSide设置为Top, VerticalOffset设置为20px,那么表示控件距离Top的距离是20px.

6、ScrollEffectDuration: 滚动效果周期设置,我不大清楚有什么用处。

CS代码，引入命名空间 using AjaxControlToolkit;