问题
Minor issue, but it's driving me nuts nonetheless.
I'm building a url for a <script> tag include to be rendered on an ASP.NET page, something like this:
<script src='<%= string.Format("http://example.com/page.aspx?a={0}&b={1}&c={2:0.00}", A, B, C)%>' type='text/javascript'></script>
Problem is when this is rendered, the & characters are replaced with &:
<script src='http://example.com/page.aspx?a=xxx&b=zzz&c=123.45' type='text/javascript'></script>
I was expecting this, obviously:
<script src='http://example.com/page.aspx?a=xxx&b=zzz&c=123.45' type='text/javascript'></script>
However, if I render the url directly, outside the <script> tag, it looks ok! Just doing
<%= string.Format("http://example.com/page.aspx?a={0}&b={1}&c={2:0.00}", A, B, C) %>
Renders this:
http://example.com/page.aspx?a=xxx&b=zzz&c=123.45
What gives? And how do I stop this madness? My OCD can't take it!
回答1:
As @Falkon and @AVD have said, ASP.NET is automatically doing the "right" thing in the <script> tag. See the w3c recommendation - C.12. Using Ampersands in Attribute Values (and Elsewhere)
In order to ensure that documents are compatible with historical HTML user agents and XML-based user agents, ampersands used in a document that are to be treated as literal characters must be expressed themselves as an entity reference (e.g. "
&").
I'm not entirely sure why ASP.NET doesn't do the same thing in the rest of the page (could be any number of good reasons), but at least it's correcting the ampersand in the script tag. Conclusion: While you may be cursing ASP.NET for "scrambling" your url, you may want to thank it instead for helping your webpage be standards compliant.
回答2:
Around the comment use Server.HtmlEncode( yourString )
It will automatically escape the double or single quotes for you, as well as ampersands (&) and less-than and greater-than signs, etc.
回答3:
Instead of <%=, which can sometimes automatically HTMLEncode things it writes to the response stream, try using <$:. This is a new(ish) code expression nugget syntax added with ASP.Net 4.0. This new syntax will still HTMLEncode most things by default, but there is a special IHtmlString interface you can use to explicitly tell this new nugget that you do not want to HTMLEncode this data, and thus avoid double encoding. You should pretty much always use the newer <%: and pretty much never use the older <%=... though of course there will be exceptions to this.
More details are available here:
http://weblogs.asp.net/scottgu/archive/2010/04/06/new-lt-gt-syntax-for-html-encoding-output-in-asp-net-4-and-asp-net-mvc-2.aspx
回答4:
"&" is a reserved character in HTML and XML, and consequently ASP.NET. The "&" gets converted by ASP.NET to & because that is the code to display that character on the web.
You might find your answer in the answers on this question : ASP.Net URLEncode Ampersand for use in Query String
Hope that helps, good luck!
回答5:
Maybe MvcHtmlString.Create() or Html.Raw()?
<script src='<%= MvcHtmlString.Create("http://example.com/page.aspx?a={0}&b={1}&c={2:0.00}", A, B, C)%>' type='text/javascript'></script>
or
<script src='<%= Html.Raw("http://example.com/page.aspx?a={0}&b={1}&c={2:0.00}", A, B, C)%>' type='text/javascript'></script>
回答6:
I can work it out. I just make a method:
public void BuildUrl(String baseUrl = "", String data = "")
{
Response.Write(baseUrl + data);
}
and use it in my html page like this:
<button type="button" class="btn_new" ref="<% this.BuildUrl(this.BaseUrl + "Master/Tanker_Edit.aspx?", "type=new&unique_id=" + Session.SessionID); %>">New</button>
The result:
<button type="button" class="btn_new" ref="http://kideco.local/Master/Tanker_Edit.aspx? type=new&unique_id=emxw1pkpnwcxpn1cl2cf04zv">
来源：https://stackoverflow.com/questions/13737902/asp-net-automatically-converts-to-amp