在回发时保持页面内div的滚动位置

I have a div within an aspx page with overflow set to auto. The contents of the div are dynamically created and consists of a list of link buttons.

我在aspx页面中有一个div，溢出设置为auto。 div的内容是动态创建的，由一系列链接按钮组成。

<div id="div1" style="overflow: auto; height: 100%;">
.....
</div>

When I scoll down in the div and click on any of the link buttons, the page reload loses the scroll position inside the div and takes me to the top of the div. Is there any way to prevent that?

当我在div中按下并单击任何链接按钮时，页面重新加载会丢失div中的滚动位置并将我带到div的顶部。有什么方法可以预防吗？

Note that this is for a div inside the page. Page.MaintainScrollPositionOnPostBack() does not work.

请注意，这是针对页面内的div。 Page.MaintainScrollPositionOnPostBack（）不起作用。

5 个解决方案

#1

As Jeff S mentioned one way to handle this situation is using javascript to track the scroll position of the div and each time the page loads reset the scroll position to its previous value.

正如Jeff S所提到的，处理这种情况的一种方法是使用javascript来跟踪div的滚动位置，每次页面加载时将滚动位置重置为其先前的值。

Here's some sample code:

这是一些示例代码：

<html>
<body onload="javascript:document.getElementById('div1').scrollTop = document.getElementById('scroll').value;">
    <form id="form1" runat="server">
    <input type="hidden" id="scroll" runat="server" />
    <div id="div1" style="overflow: auto; height: 100px;" onscroll="javascript:document.getElementById('scroll').value = this.scrollTop">
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        ...........<br />
        <asp:LinkButton ID="LinkButton1" runat="server" Text="test2"></asp:LinkButton>
    </div>
    <asp:LinkButton ID="LinkButton2" runat="server" Text="test1"></asp:LinkButton>
    </form>
</body>
</html>

In practice I wouldn't put the javascript directly in the elements but its just an example. You could also store the scroll position in a cookie instead.

在实践中，我不会将javascript直接放在元素中，但它只是一个例子。您也可以将滚动位置存储在cookie中。

#2

The easiest way is to wrap the control in an UpdatePanel.

最简单的方法是将控件包装在UpdatePanel中。

#3

using System;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls;

[ParseChildren(true, "Content")]
public class ScrollSaverPanel: WebControl
{
    [TemplateInstance(TemplateInstance.Single)]
    [PersistenceMode(PersistenceMode.InnerProperty)]
    [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
    public ITemplate Content { get; set; }

    private HiddenField HiddenField { get; set; }

    protected override HtmlTextWriterTag TagKey
    {
        get
        {
            return HtmlTextWriterTag.Div;
        }
    }

    protected override void OnInit(EventArgs e)
    {
        HiddenField = new HiddenField();

        var metaContainer = new WebControl(HtmlTextWriterTag.Div);
        metaContainer.Controls.Add(HiddenField);
        metaContainer.Style.Add(HtmlTextWriterStyle.Display, "none");

        Controls.Add(metaContainer);

        var contentContainer = new WebControl(HtmlTextWriterTag.Div);
        Controls.Add(contentContainer);

        Content.InstantiateIn(contentContainer);

        this.Style.Add(HtmlTextWriterStyle.Overflow, "auto");
        this.Attributes.Add("onscroll", string.Format("javascript:document.getElementById('{0}').value = this.scrollTop;", HiddenField.ClientID));

        base.OnInit(e);
    }

    protected override void OnPreRender(EventArgs e)
    {
        ScriptManager.RegisterStartupScript(this, this.GetType(), "setscroll", string.Format("javascript:document.getElementById('{0}').scrollTop = '{1}';", this.ClientID, HiddenField.Value), true);
        base.OnPreRender(e);
    }
}

Usage:

用法：

<general:ScrollSaverPanel runat="server">
    <Content>
        <stwrw:Group runat="server" ID="rootGroup"/>
    </Content>
</general:ScrollSaverPanel>

Since some people don't want to use an Updatepanel for the sole purpose of saving scroll position... :)

因为有些人不想使用Updatepanel只是为了保存滚动位置...... :)

#4

One way to do it is to capture, in the onscroll event of the div, the values from the scrollLeft and scrollTop properties. Save those values in a hidden text box(es). On post back, use the values from the text boxes to reset the properties.

一种方法是在div的onscroll事件中捕获scrollLeft和scrollTop属性中的值。将这些值保存在隐藏文本框中。在回发后，使用文本框中的值重置属性。

#5

What happens when the link buttons are pressed? What processing occurs during the postback?

按下链接按钮会发生什么？回发期间会发生什么处理？

Depending on the answers to those questions, you may want to investigate getting rid of the postback altogether and performing the necessary operations purely client-side.

根据这些问题的答案，您可能需要调查完全摆脱回发并完全在客户端执行必要的操作。

(I am currently performing this kind of conversion for a client.)

（我目前正在为客户端执行此类转换。）

#1