[英]What is the shortest code to compare two comma-separated strings for a match?
The method below called UserCanAccessThisPage is based on the following logic: each user and each page has a list of groups.下面称为UserCanAccessThisPage的方法基于以下逻辑:每个用户和每个页面都有一个组列表。 If any of these match, the user has access to the page.
如果其中任何一项匹配,则用户可以访问该页面。
The code below does what I want, but my solution is very C# 1 (or C# 2, at least I didn't use ArrayList).下面的代码做了我想要的,但我的解决方案是非常 C# 1 (或 C# 2,至少我没有使用 ArrayList)。
Can anyone refactor this so it is more straight-forward, eg using lambdas to do away with the two methods?任何人都可以重构这个使其更直接,例如使用 lambdas 来取消这两种方法吗? I just can't get the syntax to do it.
我只是无法获得这样做的语法。
using System;
using System.Collections.Generic;
using System.Linq;
namespace TestCompare2343
{
class Program
{
static void Main(string[] args)
{
string anonymousUserAccessGroups = "loggedOutUsers";
string normalUserAccessGroups = "loggedInUsers, members";
string developerUserAccessGroups = "loggedInUsers, members, administrators, developers";
string loginPageAccessGroups = "loggedOutUsers";
string logoutPageAccessGroups = "loggedInUsers";
string memberInfoPageAccessGroups = "members";
string devPageAccessGroups = "developers";
//test anonymousUser
Console.WriteLine(StringHelpers.UserCanAccessThisPage(anonymousUserAccessGroups, loginPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(anonymousUserAccessGroups, logoutPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(anonymousUserAccessGroups, memberInfoPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(anonymousUserAccessGroups, devPageAccessGroups));
Console.WriteLine("---");
//test anonymousUser
Console.WriteLine(StringHelpers.UserCanAccessThisPage(normalUserAccessGroups, loginPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(normalUserAccessGroups, logoutPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(normalUserAccessGroups, memberInfoPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(normalUserAccessGroups, devPageAccessGroups));
Console.WriteLine("---");
//test anonymousUser
Console.WriteLine(StringHelpers.UserCanAccessThisPage(developerUserAccessGroups, loginPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(developerUserAccessGroups, logoutPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(developerUserAccessGroups, memberInfoPageAccessGroups));
Console.WriteLine(StringHelpers.UserCanAccessThisPage(developerUserAccessGroups, devPageAccessGroups));
Console.WriteLine("---");
Console.ReadLine();
}
}
public class StringHelpers
{
public static bool UserCanAccessThisPage(string userAccessGroups, string pageItemAccessGroups)
{
List<string> userAccessGroupsList = StringHelpers.SplitAndTrimCommaDelimitedString(userAccessGroups);
List<string> pageItemAccessGroupList = StringHelpers.SplitAndTrimCommaDelimitedString(pageItemAccessGroups);
foreach (string userAccessGroup in userAccessGroupsList)
{
foreach (string pageItemAccessGroup in pageItemAccessGroupList)
{
if (userAccessGroup == pageItemAccessGroup)
return true;
}
}
return false;
}
public static List<string> SplitAndTrimCommaDelimitedString(string line)
{
List<string> piecesWithSpaces = line.Split(',').ToList<string>();
List<string> piecesWithoutSpaces = new List<string>();
foreach (string pieceWithSpace in piecesWithSpaces)
{
piecesWithoutSpaces.Add(pieceWithSpace.Trim());
}
return piecesWithoutSpaces;
}
}
}
Fredrik had the most concise code that solved the original task above: Fredrik 有最简洁的代码来解决上面的原始任务:
public static bool UserCanAccessThisPage(string userAccessGroups, string pageItemAccessGroups)
{
return userAccessGroups
.Split(',')
.Select(s => s.Trim())
.Contains(pageItemAccessGroups);
}
But Shaul was correct in assuming that the PageItems can also have multiple entries, eg "members,guests", and so I actually used Shaul's code:但是 Shaul 假设 PageItems 也可以有多个条目是正确的,例如“成员,客人”,所以我实际上使用了 Shaul 的代码:
public static bool UserCanAccessThisPage(string userAccessGroups, string pageItemAccessGroups) {
List<string> userAccessGroupsList = StringHelpers.SplitAndTrimCommaDelimitedString(userAccessGroups);
List<string> pageItemAccessGroupList = StringHelpers.SplitAndTrimCommaDelimitedString(pageItemAccessGroups);
return userAccessGroupsList.Any(userAccessGroup => pageItemAccessGroupList.Any(pageItemAccessGroup => userAccessGroup == pageItemAccessGroup));
}
public static List<string> SplitAndTrimCommaDelimitedString(string line) {
return line.Split(',').Select(s => s.Trim()).ToList();
}
OK, you said you wanted compact...!好吧,你说你想要紧凑......! :)
:)
public static bool UserCanAccessThisPage(string userAccessGroups, string pageItemAccessGroups) {
List<string> userAccessGroupsList = StringHelpers.SplitAndTrimCommaDelimitedString(userAccessGroups);
List<string> pageItemAccessGroupList = StringHelpers.SplitAndTrimCommaDelimitedString(pageItemAccessGroups);
return userAccessGroupsList.Any(userAccessGroup => pageItemAccessGroupList.Any(pageItemAccessGroup => userAccessGroup == pageItemAccessGroup));
// or:
// return userAccessGroupsList.Any(userAccessGroup => pageItemAccessGroupList.Contains(userAccessGroup));
}
public static List<string> SplitAndTrimCommaDelimitedString(string line) {
return line.Split(',').Select(s => s.Trim()).ToList();
}
StringHelpers could look like this: StringHelpers 可能如下所示:
public class StringHelpers
{
private static readonly char[] separator = ",".ToCharArray();
public static bool UserCanAccessThisPage(
string userAccessGroups,
string pageItemAccessGroups)
{
return userAccessGroups
.Split(separator) // split on comma
.Select(s => s.Trim()) // trim elements
.Contains(pageItemAccessGroups); // match
}
}
public static bool UserCanAccessThisPage(
string userAccessGroups, string pageItemAccessGroups)
{
HashSet<string> u = new HashSet<string>(
userAccessGroups.Split(',').Select(x => x.Trim()));
return u.Overlaps(pageItemAccessGroups.Split(',').Select(x => x.Trim()));
}
Once you have the two IEnumerable<string>
s, you can use the Intersect
function:一旦你有了两个
IEnumerable<string>
,你就可以使用Intersect
函数:
return userGroups.Intersect(pageGroups).Count > 0;
This is in case you need the full list of permissions for the user on the page.这是为了防止您需要页面上用户的完整权限列表。
However, I'd go with Shaul's example: the Any
function is faster, it should stop at the first match.但是,我会使用 Shaul 的示例:
Any
函数更快,它应该在第一场比赛时停止。
Something like (sorry no IDE to hand)类似的东西(抱歉没有 IDE)
public static bool UserCanAccessThisPage(string userAccessGroups, string pageItemAccessGroups)
{
List<string> userAccessGroupsList = StringHelpers.SplitAndTrimCommaDelimitedString(userAccessGroups);
List<string> pageItemAccessGroupList = StringHelpers.SplitAndTrimCommaDelimitedString(pageItemAccessGroups);
return userAccessGroupsList.Where(
uag => pageItemAccessGroupList.Contains(uag)).Count > 0;
}
public static List<string> SplitAndTrimCommaDelimitedString(string line)
{
return line.Split(',').Select(s => s.Trim()).ToList<string>();
}
I really don't see a big problem with it having two methods, since the functionality is nicely separated, but I guess you could move the code from the second method inline to the first if you really want to.我真的不认为它有两种方法有什么大问题,因为功能很好地分开了,但我想如果你真的想要的话,你可以将代码从第二个方法内联移动到第一个方法。
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