提交页面的定位--scrollIntoView的用法

提交页面定位问题一直骚扰我，比如我们在DataGrid外面加了来使DataGrid在一定区域内呈现，这样如果把滚动条拉到底部的时候点击修改（或者修改后点击更新，取消）页面重新加载的时候都会把滚动条拉到页面最上面部分 ，特此我将下面知识共享一下:

object.scrollIntoView( [bAlignToTop])

Parameters

bAlignToTop

Optional. Booleanthat specifies one of the following values: true Default. Scrolls the object so that top of the object is visible at the top of the window. false Scrolls the object so that the bottom of the object is visible at the bottom of the window.

Return Value

No return value.

Remarks

The scrollIntoView method is useful for immediately showing the user the result of some action without requiring the user to manually scroll through the document to find the result.

Depending on the size of the given object and the current window, this method might not be able to put the item at the very top or very bottom, but will position the object as close to the requested position as possible.

Example

This example uses the scrollIntoView method to underline the content of the document's fifth paragraph and scroll it into view at the top of the window.

HideExample

   var coll = document.all.tags("P");
if (coll.length >= 5)
{
coll(4).style.textDecoration = "underline";
coll(4).scrollIntoView(true);
}

Standards Information

There is no public standard that applies to this method.

Applies To

INPUT type=ra... Platform Version Win16: 4.0 Win32: 4.0 WindowsCE: 4.0 Unix: 4.0 Mac: 4.0 Version data is listed when the mouse hovers over a link, or the link has focus.

A, ADDRESS, APPLET, AREA, B, BIG, BLOCKQUOTE, BR, BUTTON, CAPTION, CENTER, CITE, CODE, COL, COLGROUP, COMMENT, controlRange, CUSTOM, DD, DFN, DIR, DIV, DL, DT, EM, EMBED, FIELDSET, FONT, FORM, hn, HR, I, IFRAME, IMG, INPUT type=button, INPUT type=checkbox, INPUT type=file, INPUT type=image, INPUT type=password, INPUT type=radio, INPUT type=reset, INPUT type=submit, INPUT type=text, KBD, LABEL, LEGEND, LI, LISTING, MAP, MARQUEE, MENU, NOBR, OBJECT, OL, P, PLAINTEXT, PRE, S, SAMP, SELECT, SMALL, SPAN, STRIKE, STRONG, SUB, SUP, TABLE, TBODY, TD, TEXTAREA, TextRange, TFOOT, TH, THEAD, TR, TT, U, UL, VAR, WBR, XMP

Move the mouse pointer over an element in the Applies To list to display availability information for the listed platforms.

二、在.Net中的应用
1、定位指定控件
/// <summary>
/// 定位txtCode控件
/// </summary>
private void Scroll()
{
string s="<script>function window.onload(){document.all('"+this.txtCode.ClientID+"').scrollIntoView();}</script>";
Page.RegisterStartupScript("",s);
}

2、定位指定DataGrid列

< div style ="BORDER:0px;PADDING:0px;MARGIN:0px;OVERFLOW:scroll;WIDTH:600px;HEIGHT:200px" align ="center" >

现在给出一种简单的办法（其他的一些利用锚点等办法都比较复杂）

private void Scroll( int index)
{
strings="<script>functionwindow.onload(){document.all('"+this.DataGrid1.ClientID+"').rows["+index+"].scrollIntoView();}</script>";
Page.RegisterStartupScript("",s);
}

写了一个方法，其中DataGrid1换成自己的DataGrid的ID，这个方法传递进去的参数就是行号，也就是e.Item.ItemIndex。
比如在编辑操作的时候会写this.DataGrid1.EditItemIndex=e.Item.ItemIndex;
在此语句的以前加入Scroll(e.Item.ItemIndex);就可以了
同样在更新操作的时候写为Scroll(e.Item.ItemIndex);this.DataGrid1.EditItemIndex=-1;绑定;

利用MaintainScrollPositionOnPostback属性
考虑到一个很长的页面,如果每次POSTBACK之后,那个IE的滚动条可能都会回到最开始的地方(最上面),而不会保留其原先已经有的位置,这样用户会比较麻烦，又要把滚动条移动到原来的地方,在asp.net 2.0中,可以设置MaintainScrollPositionOnPostback属性为TRUE即可,即
<%@ Page Language="VB" AutoEventWireup="false" MaintainScrollPositionOnPostback="true" CodeFile="MaintainScrollPosition.aspx.vb" Inherits="MaintainScrollPosition" %>