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:
?12345678910111213 <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:
?12345678910 protected void Button1_Click(object sender, EventArgs e) { //单击按钮后批量改变li元素的内联文本值及样式 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:
?12345678910111213 <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:
?1234567891011121314 private int counter = 1; protected void Button1_Click(object sender, EventArgs e) { //单击按钮后批量改变li元素的内联文本值及样式 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:
?1234567891011121314 <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:
?12345678910111213 protected void Button1_Click(object sender, EventArgs e) { //单击按钮后批量改变li元素的内联文本值及样式 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。
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