using StringEx

shadowsocks-csharp/Controller/System/SystemProxy.cs

@@ -60,7 +60,7 @@ namespace Shadowsocks.Controller
                     else
                     {
                         string pacUrl;
-                        if (config.useOnlinePac && !string.IsNullOrEmpty(config.pacUrl))
+                        if (config.useOnlinePac && !config.pacUrl.IsNullOrEmpty())
                             pacUrl = config.pacUrl;
                         else
                             pacUrl = $"http://127.0.0.1:{config.localPort}/pac?t={GetTimestamp(DateTime.Now)}";

shadowsocks-csharp/Encryption/EncryptorFactory.cs

@@ -25,7 +25,7 @@ namespace Shadowsocks.Encryption
 
         public static IEncryptor GetEncryptor(string method, string password, bool onetimeauth, bool isudp)
         {
-            if (string.IsNullOrEmpty(method))
+            if (method.IsNullOrEmpty())
             {
                 method = "aes-256-cfb";
             }

shadowsocks-csharp/Model/Configuration.cs

@@ -124,13 +124,13 @@ namespace Shadowsocks.Model
 
         private static void CheckPassword(string password)
         {
-            if (string.IsNullOrEmpty(password))
+            if (password.IsNullOrEmpty())
                 throw new ArgumentException(I18N.GetString("Password can not be blank"));
         }
 
         private static void CheckServer(string server)
         {
-            if (string.IsNullOrEmpty(server))
+            if (server.IsNullOrEmpty())
                 throw new ArgumentException(I18N.GetString("Server IP can not be blank"));
         }
     }

shadowsocks-csharp/Model/Server.cs

@@ -29,11 +29,11 @@ namespace Shadowsocks.Model
 
         public string FriendlyName()
         {
-            if (string.IsNullOrEmpty(server))
+            if (server.IsNullOrEmpty())
             {
                 return I18N.GetString("New server");
             }
-            if (string.IsNullOrEmpty(remarks))
+            if (remarks.IsNullOrEmpty())
             {
                 return server + ":" + server_port;
             }

shadowsocks-csharp/StringEx.cs

@@ -0,0 +1,196 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+using System.Text;
+
+static partial class StringEx
+{
+#pragma warning disable 1591
+
+    public static StringComparison GlobalDefaultComparison { get; set; } = StringComparison.Ordinal;
+
+    [ThreadStatic]
+    private static StringComparison? _DefaultComparison;
+    public static StringComparison DefaultComparison
+    {
+        get { return _DefaultComparison ?? GlobalDefaultComparison; }
+        set { _DefaultComparison = value; }
+    }
+
+    #region basic String methods
+
+    public static bool IsNullOrEmpty(this string value)
+        => string.IsNullOrEmpty(value);
+
+    public static bool IsNullOrWhiteSpace(this string value)
+        => string.IsNullOrWhiteSpace(value);
+
+#if !PCL
+    public static string IsInterned(this string value)
+    {
+        if (value == null)
+            throw new ArgumentNullException(nameof(value));
+
+        return string.IsInterned(value);
+    }
+
+    public static string Intern(this string value)
+    {
+        if (value == null)
+            throw new ArgumentNullException(nameof(value));
+
+        return string.Intern(value);
+    }
+#endif
+
+    #endregion
+
+    #region comparing
+
+    #region Is
+
+    public static bool Is(this string a, string b)
+        => string.Equals(a, b, DefaultComparison);
+    public static bool Is(this string a, string b, StringComparison comparisonType)
+        => string.Equals(a, b, comparisonType);
+
+    #endregion
+
+    #region BeginWith
+
+    public static bool BeginWith(this string s, char c)
+    {
+        if (s.IsNullOrEmpty()) return false;
+        return s[0] == c;
+    }
+    public static bool BeginWithAny(this string s, IEnumerable<char> chars)
+    {
+        if (s.IsNullOrEmpty()) return false;
+        return chars.Contains(s[0]);
+    }
+    public static bool BeginWithAny(this string s, params char[] chars)
+        => s.BeginWithAny(chars.AsEnumerable());
+
+    public static bool BeginWith(this string a, string b)
+    {
+        if (a == null || b == null) return false;
+
+        return a.StartsWith(b, DefaultComparison);
+    }
+    public static bool BeginWith(this string a, string b, StringComparison comparisonType)
+    {
+        if (a == null || b == null) return false;
+
+        return a.StartsWith(b, comparisonType);
+    }
+#if !PCL
+    public static bool BeginWith(this string a, string b, bool ignoreCase, CultureInfo culture)
+    {
+        if (a == null || b == null) return false;
+
+        return a.StartsWith(b, ignoreCase, culture);
+    }
+#endif
+
+    #endregion
+
+    #region FinishWith
+
+    public static bool FinishWith(this string s, char c)
+    {
+        if (s.IsNullOrEmpty()) return false;
+        return s.Last() == c;
+    }
+    public static bool FinishWithAny(this string s, IEnumerable<char> chars)
+    {
+        if (s.IsNullOrEmpty()) return false;
+        return chars.Contains(s.Last());
+    }
+    public static bool FinishWithAny(this string s, params char[] chars)
+        => s.FinishWithAny(chars.AsEnumerable());
+
+    public static bool FinishWith(this string a, string b)
+    {
+        if (a == null || b == null) return false;
+
+        return a.EndsWith(b, DefaultComparison);
+    }
+    public static bool FinishWith(this string a, string b, StringComparison comparisonType)
+    {
+        if (a == null || b == null) return false;
+
+        return a.EndsWith(b, comparisonType);
+    }
+#if !PCL
+    public static bool FinishWith(this string a, string b, bool ignoreCase, CultureInfo culture)
+    {
+        if (a == null || b == null) return false;
+
+        return a.EndsWith(b, ignoreCase, culture);
+    }
+#endif
+
+    #endregion
+
+    #endregion
+
+    #region others
+
+    private static readonly char[][] Quotes = new[]
+    {
+        "\"\"",
+        "''",
+        "“”",
+        "‘’",
+        "『』",
+        "「」",
+        "〖〗",
+        "【】",
+    }.Select(s => s.ToCharArray()).ToArray();
+    public static string Enquote(this string value)
+    {
+        if (value == null)
+            return "(null)";
+
+        foreach (var pair in Quotes)
+        {
+            if (value.IndexOfAny(pair) < 0)
+                return pair[0] + value + pair[1];
+        }
+
+        return '"' + value.Replace("\\", @"\\").Replace("\"", @"\""") + '"';
+    }
+
+    public static string Replace(this string value, string find, string rep, StringComparison comparsionType)
+    {
+        if (find.IsNullOrEmpty())
+            throw new ArgumentException(null, nameof(find));
+        if (rep == null)
+            rep = "";
+        if (value.IsNullOrEmpty())
+            return value;
+
+        var sb = new StringBuilder(value.Length);
+
+        var last = 0;
+        var len = find.Length;
+        var idx = value.IndexOf(find, DefaultComparison);
+        while (idx != -1)
+        {
+            sb.Append(value.Substring(last, idx - last));
+            sb.Append(rep);
+            idx += len;
+
+            last = idx;
+            idx = value.IndexOf(find, idx, comparsionType);
+        }
+        sb.Append(value.Substring(last));
+
+        return sb.ToString();
+    }
+    public static string ReplaceEx(this string value, string find, string rep)
+        => value.Replace(find, rep, DefaultComparison);
+
+    #endregion
+}

shadowsocks-csharp/View/MenuViewController.cs

@@ -630,11 +630,11 @@ namespace Shadowsocks.View
         {
             if (!onlinePACItem.Checked)
             {
-                if (String.IsNullOrEmpty(controller.GetConfigurationCopy().pacUrl))
+                if (controller.GetConfigurationCopy().pacUrl.IsNullOrEmpty())
                 {
                     UpdateOnlinePACURLItem_Click(sender, e);
                 }
-                if (!String.IsNullOrEmpty(controller.GetConfigurationCopy().pacUrl))
+                if (!controller.GetConfigurationCopy().pacUrl.IsNullOrEmpty())
                 {
                     localPACItem.Checked = false;
                     onlinePACItem.Checked = true;
@@ -651,7 +651,7 @@ namespace Shadowsocks.View
                 I18N.GetString("Please input PAC Url"),
                 I18N.GetString("Edit Online PAC URL"),
                 origPacUrl, -1, -1);
-            if (!string.IsNullOrEmpty(pacUrl) && pacUrl != origPacUrl)
+            if (!pacUrl.IsNullOrEmpty() && pacUrl != origPacUrl)
             {
                 controller.SavePACUrl(pacUrl);
             }

shadowsocks-csharp/packages.config

@@ -8,5 +8,6 @@
   <package id="Microsoft.Bcl.Build" version="1.0.21" targetFramework="net40-client" />
   <package id="Microsoft.Net.Http" version="2.0.20710.0" targetFramework="net4-client" />
   <package id="Newtonsoft.Json" version="8.0.2" targetFramework="net40-client" />
+  <package id="StringEx" version="0.1.1" targetFramework="net40-client" />
   <package id="System.Net.Http" version="2.0.20710.0" targetFramework="net40-client" />
 </packages>

shadowsocks-csharp/shadowsocks-csharp.csproj

@@ -204,6 +204,7 @@
     <Compile Include="Controller\Strategy\BalancingStrategy.cs" />
     <Compile Include="Controller\Strategy\StrategyManager.cs" />
     <Compile Include="Controller\Strategy\IStrategy.cs" />
+    <Compile Include="StringEx.cs" />
     <Compile Include="Util\Util.cs" />
     <Compile Include="View\ConfigForm.cs">
       <SubType>Form</SubType>