C# Uri.MakeRelative方法代码示例

        // Return the relative vpath path from one rooted vpath to another
        internal static string MakeRelative(string from, string to)
        {
            // If either path is app relative (~/...), make it absolute, since the Uri
            // class wouldn't know how to deal with it.
            from = MakeVirtualPathAppAbsolute(from);
            to = MakeVirtualPathAppAbsolute(to);

            // Make sure both virtual paths are rooted
            Debug.Assert(IsRooted(from));
            Debug.Assert(IsRooted(to));

            // Uri's need full url's so, we use a dummy root
            Uri fromUri = new Uri(dummyProtocolAndServer + from);
            Uri toUri = new Uri(dummyProtocolAndServer + to);
            return fromUri.MakeRelative(toUri);
        }

		protected override void RenderAttributes (HtmlTextWriter w)
		{
			/* Need to always render: method, action and id
			 */
			
			string action;
			string customAction = Attributes ["action"];
			Page page = Page;
			HttpRequest req = page != null ? page.RequestInternal : null;
			if (String.IsNullOrEmpty (customAction)) {
				string file_path = req != null ? req.ClientFilePath : null;
				string current_path = req != null ? req.CurrentExecutionFilePath : null;

				if (file_path == null)
					action = Action;
				else if (file_path == current_path) {
					// Just the filename will do
					action = UrlUtils.GetFile (file_path);
				} else {
					// Fun. We need to make cookieless sessions work, so no
					// absolute paths here.
					bool cookieless;
					SessionStateSection sec = WebConfigurationManager.GetSection ("system.web/sessionState") as SessionStateSection;
					cookieless = sec != null ? sec.Cookieless == HttpCookieMode.UseUri: false;
					string appVPath = HttpRuntime.AppDomainAppVirtualPath;
					int appVPathLen = appVPath.Length;
						
					if (appVPathLen > 1) {
						if (cookieless) {
							if (StrUtils.StartsWith (file_path, appVPath, true))
								file_path = file_path.Substring (appVPathLen + 1);
						} else if (StrUtils.StartsWith (current_path, appVPath, true))
							current_path = current_path.Substring (appVPathLen + 1);
					}
					
					if (cookieless) {
						Uri current_uri = new Uri ("http://host" + current_path);
						Uri fp_uri = new Uri ("http://host" + file_path);
						action = fp_uri.MakeRelative (current_uri);
					} else
						action = current_path;
				}
			} else
				action = customAction;
			if (req != null)
				action += req.QueryStringRaw;
			if (req != null) {
				XhtmlConformanceSection xhtml = WebConfigurationManager.GetSection ("system.web/xhtmlConformance") as XhtmlConformanceSection;
				if (xhtml == null || xhtml.Mode != XhtmlConformanceMode.Strict)
#if NET_4_0
					if (RenderingCompatibilityLessThan40)
#endif
						// LAMESPEC: MSDN says the 'name' attribute is rendered only in
						// Legacy mode, this is not true.
						w.WriteAttribute ("name", Name);
			}
			
			w.WriteAttribute ("method", Method);
			if (String.IsNullOrEmpty (customAction))
				w.WriteAttribute ("action", action, true);

			/*
			 * This is a hack that guarantees the ID is set properly for HtmlControl to
			 * render it later on. As ugly as it is, we use it here because of the way
			 * the ID, ClientID and UniqueID properties work internally in our Control
			 * code.
			 *
			 * Fixes bug #82596
			 */
			if (ID == null) {
#pragma warning disable 219
				string client = ClientID;
#pragma warning restore 219
			}
			
			string submit = page != null ? page.GetSubmitStatements () : null;
			if (!String.IsNullOrEmpty (submit)) {
				Attributes.Remove ("onsubmit");
				w.WriteAttribute ("onsubmit", submit);
			}
			
			/* enctype and target should not be written if
			 * they are empty
			 */
			string enctype = Enctype;
			if (!String.IsNullOrEmpty (enctype))
				w.WriteAttribute ("enctype", enctype);

			string target = Target;
			if (!String.IsNullOrEmpty (target))
				w.WriteAttribute ("target", target);

			string defaultbutton = DefaultButton;
			if (!String.IsNullOrEmpty (defaultbutton)) {
				Control c = FindControl (defaultbutton);

				if (c == null || !(c is IButtonControl))
					throw new InvalidOperationException(String.Format ("The DefaultButton of '{0}' must be the ID of a control of type IButtonControl.",
											   ID));

//.........这里部分代码省略.........

	public void TestUriMakeRelative()
	{
		Uri gnuphil = new Uri("http://www.gnu.org/philosophy/why-free.html");
		Uri gnuoreilly = new Uri("http://www.gnu.org/gnu/thegnuproject.html");
		Uri mozillaftp = new Uri("ftp://ftp.mozilla.org/pub/mozilla/latest/mozilla-i686-pc-linux-gnu-sea.tar.gz");
		Uri mozillahttp = new Uri("http://ftp.mozilla.org/pub/mozilla/latest/mozilla-i686-pc-linux-gnu-sea.tar.gz");
		Uri mandrake = new Uri("ftp://distro.ibiblio.org/pub/Linux/distributions/mandrake/Mandrake/iso/");
		Uri debian = new Uri("ftp://distro.ibiblio.org/pub/Linux/distributions/debian/main/");
		Uri debianrelease = new Uri("ftp://distro.ibiblio.org/pub/Linux/distributions/debian/main/source/Release");

		AssertEquals(
				"Code figures out simple relative Uri correctly (with files)",
			     gnuphil.MakeRelative(gnuoreilly),
			     "../gnu/thegnuproject.html");
		AssertEquals("notices different schemes when comparing Uris",
			     mozillaftp.MakeRelative(mozillahttp),
			     mozillahttp.AbsoluteUri);
		AssertEquals("figures out more complex, directory-based relative Uri",
			     mandrake.MakeRelative(debian),
			     "../../../debian/main/");
		AssertEquals("tells difference between files and directorys, by looking for ending slash",
			debianrelease.MakeRelative(debian), "../");
		AssertEquals("correctly goes further into subdirectories",
			debian.MakeRelative(debianrelease), "source/Release");
	}

		protected override void RenderAttributes (HtmlTextWriter w)
		{
			/* Need to always render: method, action and id
			 */
			/* The name attribute is rendered _only_ if we're not in
			   2.0 mode or if the xhtml conformance mode is set to
			   Legacy for 2.0 according to http://msdn2.microsoft.com/en-us/library/system.web.ui.htmlcontrols.htmlform.name.aspx
			*/
			
			string action;
			string customAction = Attributes ["action"];
			Page page = Page;
			HttpRequest req = page != null ? page.Request : null;
			if (req == null)
				throw new HttpException ("No current request, cannot continue rendering.");
#if !TARGET_J2EE
			if (String.IsNullOrEmpty (customAction)) {
				string file_path = req.ClientFilePath;
				string current_path = req.CurrentExecutionFilePath;
				if (file_path == current_path) {
					// Just the filename will do
					action = UrlUtils.GetFile (file_path);
				} else {
					// Fun. We need to make cookieless sessions work, so no
					// absolute paths here.
					bool cookieless;
					SessionStateSection sec = WebConfigurationManager.GetSection ("system.web/sessionState") as SessionStateSection;
					cookieless = sec != null ? sec.Cookieless == HttpCookieMode.UseUri: false;
					string appVPath = HttpRuntime.AppDomainAppVirtualPath;
					int appVPathLen = appVPath.Length;
						
					if (appVPathLen > 1) {
						if (cookieless) {
							if (StrUtils.StartsWith (file_path, appVPath, true))
								file_path = file_path.Substring (appVPathLen);
						} else if (StrUtils.StartsWith (current_path, appVPath, true))
							current_path = current_path.Substring (appVPathLen);
					}
					
					if (cookieless) {
						Uri current_uri = new Uri ("http://host" + current_path);
						Uri fp_uri = new Uri ("http://host" + file_path);
						action = fp_uri.MakeRelative (current_uri);
					} else
						action = current_path;
				}
			} else
				action = customAction;
			action += req.QueryStringRaw;
#else
			// Allow the page to transform action to a portlet action url
			if (String.IsNullOrEmpty (customAction)) {
				string queryString = req.QueryStringRaw;
				action = CreateActionUrl (VirtualPathUtility.ToAppRelative (req.CurrentExecutionFilePath) +
					(string.IsNullOrEmpty (queryString) ? string.Empty : "?" + queryString));
			}
			else
				action = customAction;

#endif

			XhtmlConformanceSection xhtml = WebConfigurationManager.GetSection ("system.web/xhtmlConformance") as
				XhtmlConformanceSection;
			
			if (xhtml != null && xhtml.Mode == XhtmlConformanceMode.Legacy)
				w.WriteAttribute ("name", Name);

			w.WriteAttribute ("method", Method);
			if (String.IsNullOrEmpty (customAction))
				w.WriteAttribute ("action", action, true);

			/*
			 * This is a hack that guarantees the ID is set properly for HtmlControl to
			 * render it later on. As ugly as it is, we use it here because of the way
			 * the ID, ClientID and UniqueID properties work internally in our Control
			 * code.
			 *
			 * Fixes bug #82596
			 */
			if (ID == null) {
#pragma warning disable 219
				string client = ClientID;
#pragma warning restore 219
			}
			
			string submit = page != null ? page.GetSubmitStatements () : null;
			if (!String.IsNullOrEmpty (submit)) {
				Attributes.Remove ("onsubmit");
				w.WriteAttribute ("onsubmit", submit);
			}
			
			/* enctype and target should not be written if
			 * they are empty
			 */
			string enctype = Enctype;
			if (!String.IsNullOrEmpty (enctype))
				w.WriteAttribute ("enctype", enctype);

			string target = Target;
			if (!String.IsNullOrEmpty (target))
//.........这里部分代码省略.........

    // Return the relative vpath path from one rooted vpath to another
    internal static string MakeRelative(string from, string to) {

        // If either path is app relative (~/...), make it absolute, since the Uri
        // class wouldn't know how to deal with it.
        from = MakeVirtualPathAppAbsolute(from);
        to = MakeVirtualPathAppAbsolute(to);

        // Make sure both virtual paths are rooted
        if (!IsRooted(from))
            throw new ArgumentException(SR.GetString(SR.Path_must_be_rooted, from));
        if (!IsRooted(to))
            throw new ArgumentException(SR.GetString(SR.Path_must_be_rooted, to));

        // Remove the query string, so that System.Uri doesn't corrupt it
        string queryString = null;
        if (to != null) {
            int iqs = to.IndexOf('?');
            if (iqs >= 0) {
                queryString = to.Substring(iqs);
                to = to.Substring(0, iqs);
            }
        }

        // Uri's need full url's so, we use a dummy root
        Uri fromUri = new Uri(dummyProtocolAndServer + from);
        Uri toUri = new Uri(dummyProtocolAndServer + to);

        string relativePath;

        // VSWhidbey 144946: If to and from points to identical path (excluding query and fragment), just use them instead
        // of returning an empty string.
        if (fromUri.Equals(toUri)) {
            int iPos = to.LastIndexOfAny(s_slashChars);

            if (iPos >= 0) {

                // If it's the same directory, simply return "./"
                // Browsers should interpret "./" as the original directory.
                if (iPos == to.Length - 1) {
                    relativePath = "./";
                }
                else {
                    relativePath = to.Substring(iPos + 1);
                }
            }
            else {
                relativePath = to;
            }
        }
        else {
// To avoid deprecation warning.  It says we should use MakeRelativeUri instead (which returns a Uri),
// but we wouldn't gain anything from it.  The way we use MakeRelative is hacky anyway (fake protocol, ...),
// and I don't want to take the chance of breaking something with this change.
#pragma warning disable 0618
            relativePath = fromUri.MakeRelative(toUri);
#pragma warning restore 0618
        }

        // Note that we need to re-append the query string and fragment (e.g. #anchor)
        return relativePath + queryString + toUri.Fragment;
    }

        public static void TestMakeRelative()
        {
            // Create a base Uri.
            Uri address1 = new Uri("http://www.contoso.com/");
            Uri address2 = new Uri("http://www.contoso.com:8000/");
            Uri address3 = new Uri("http://[email protected]/");

            // Create a new Uri from a string.
            Uri address4 = new Uri("http://www.contoso.com/index.htm?date=today");
#pragma warning disable 0618
            // Determine the relative Uri.
            string uriStr1 = address1.MakeRelative(address4);
            string uriStr2 = address2.MakeRelative(address4);
            string uriStr3 = address3.MakeRelative(address4);
#pragma warning restore 0618

            Assert.Equal(uriStr1, @"index.htm");
            Assert.Equal(uriStr2, @"http://www.contoso.com/index.htm?date=today");
            Assert.Equal(uriStr3, @"index.htm");
        }

        public static void TestMakeRelative_Invalid()
        {
            var baseUri = new Uri("http://www.domain.com/");
            var relativeUri = new Uri("/path/", UriKind.Relative);
#pragma warning disable 0618
            Assert.Throws<ArgumentNullException>("toUri", () => baseUri.MakeRelative(null)); // Uri is null

            Assert.Throws<InvalidOperationException>(() => relativeUri.MakeRelative(baseUri)); // Base uri is relative
            Assert.Throws<InvalidOperationException>(() => baseUri.MakeRelative(relativeUri)); // Uri is relative
#pragma warning restore 0618
        }