在网页开发中,经常要用到无序列表。事实上在符合W3C标准的div+css布局中,无序列表被大量使用,ASP.NET虽然内置了BulletedList控件,用于创建和操作无序列表,但感觉不太好用。本篇介绍服务器端ASP.NET批量操作基于原生html标签的无序列表的三种方法。
方法一,将li元素做成html控件,加上id,用FindControl方法。
aspx代码:
[html] view plaincopy
class="dp-xml" start="1">
- <form id="form1" runat="server">
- <ul>
- <li id="li1" runat="server">初始值1</li>
- <li id="li2" runat="server">初始值2</li>
- <li id="li3" runat="server">初始值3</li>
- <li id="li4" runat="server">初始值4</li>
- <li id="li5" runat="server">初始值5</li>
- <li id="li6" runat="server">初始值6</li>
- <li id="li7" runat="server">初始值7</li>
- <li id="li8" runat="server">初始值8</li>
- </ul>
- <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
- </form>
aspx.cs代码:
[csharp] view plaincopy
- protected void Button1_Click(object sender, EventArgs e)
- {
-
- for (int i = 1; i <= 8; i++)
- {
- HtmlGenericControl li = this.FindControl("li" + i) as HtmlGenericControl;
- li.InnerHtml = "新值" + i.ToString();
- li.Attributes.CssStyle.Value = "color:red";
- }
- }
方法二,将ul、li元素做成html控件,用ul控件的Controls集合遍历。
aspx代码:
[html] view plaincopy
- <form id="form1" runat="server">
- <ul id="ul1" runat="server">
- <li runat="server">初始值1</li>
- <li runat="server">初始值2</li>
- <li runat="server">初始值3</li>
- <li runat="server">初始值4</li>
- <li runat="server">初始值5</li>
- <li runat="server">初始值6</li>
- <li runat="server">初始值7</li>
- <li runat="server">初始值8</li>
- </ul>
- <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
- </form>
aspx.cs代码:
[csharp] view plaincopy
- private int counter = 1;
- protected void Button1_Click(object sender, EventArgs e)
- {
-
- foreach (Control control in ul1.Controls)
- {
- if (control is HtmlGenericControl)
- {
- HtmlGenericControl li = control as HtmlGenericControl;
- li.InnerHtml = "新值" + (counter++).ToString();
- li.Attributes.CssStyle.Value = "color:red";
- }
- }
- }
方法三,利用HtmlAgilityPack,对元素以Dom方式操作。
aspx代码:
[html] view plaincopy
- <form id="form1" runat="server">
- <ul id="ul1" runat="server">
- <li>初始值1</li>
- <li>初始值2</li>
- <li>初始值3</li>
- <li>初始值4</li>
- <li>初始值5</li>
- <li>初始值6</li>
- <li>初始值7</li>
- <li>初始值8</li>
- </ul>
- <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
- <asp:Button ID="Button2" runat="server" Text="测试空回发" />
- </form>
aspx.cs代码:
[csharp] view plaincopy
- protected void Button1_Click(object sender, EventArgs e)
- {
-
- HtmlDocument htmlDoc = new HtmlDocument();
- htmlDoc.LoadHtml(ul1.InnerHtml);
- HtmlNodeCollection lis = htmlDoc.DocumentNode.SelectNodes("li");
- for (int i = 0; i < lis.Count; i++)
- {
- lis[i].InnerHtml = "新值" + (i + 1).ToString();
- lis[i].Attributes.Add("style", "color:red");
- }
- ul1.InnerHtml = htmlDoc.DocumentNode.InnerHtml;
- }
以上三种方法各有优缺点,可根据实际情况选用。