diff --git a/v2rayN/v2rayN/Forms/MainForm.cs b/v2rayN/v2rayN/Forms/MainForm.cs
index 9c1d4517..9f988b60 100644
--- a/v2rayN/v2rayN/Forms/MainForm.cs
+++ b/v2rayN/v2rayN/Forms/MainForm.cs
@@ -960,7 +960,7 @@ namespace v2rayN.Forms
 
         private void notifyMain_MouseClick(object sender, MouseEventArgs e)
         {
-            if (e.Button == System.Windows.Forms.MouseButtons.Left)
+            if (e.Button == MouseButtons.Left)
             {
                 ShowForm();
             }
@@ -1370,12 +1370,12 @@ namespace v2rayN.Forms
 
         private void tsbAbout_Click(object sender, EventArgs e)
         {
-            System.Diagnostics.Process.Start(Global.AboutUrl);
+            Process.Start(Global.AboutUrl);
         }
 
         private void tsbPromotion_Click(object sender, EventArgs e)
         {
-            System.Diagnostics.Process.Start($"{Utils.Base64Decode(Global.PromotionUrl)}?t={DateTime.Now.Ticks}");
+            Process.Start($"{Utils.Base64Decode(Global.PromotionUrl)}?t={DateTime.Now.Ticks}");
         }
         #endregion
 
@@ -1507,7 +1507,7 @@ namespace v2rayN.Forms
 
         private void tsbV2rayWebsite_Click(object sender, EventArgs e)
         {
-            System.Diagnostics.Process.Start(Global.v2rayWebsiteUrl);
+            Process.Start(Global.v2rayWebsiteUrl);
         }
     }
 }
diff --git a/v2rayN/v2rayN/Handler/SpeedtestHandler.cs b/v2rayN/v2rayN/Handler/SpeedtestHandler.cs
index b8e43bc9..5d437869 100644
--- a/v2rayN/v2rayN/Handler/SpeedtestHandler.cs
+++ b/v2rayN/v2rayN/Handler/SpeedtestHandler.cs
@@ -221,7 +221,7 @@ namespace v2rayN.Handler
 
             try
             {
-                if (!System.Net.IPAddress.TryParse(url, out IPAddress ipAddress))
+                if (!IPAddress.TryParse(url, out IPAddress ipAddress))
                 {
                     IPHostEntry ipHostInfo = System.Net.Dns.GetHostEntry(url);
                     ipAddress = ipHostInfo.AddressList[0];
diff --git a/v2rayN/v2rayN/HttpProxyHandler/ProxySetting.cs b/v2rayN/v2rayN/HttpProxyHandler/ProxySetting.cs
index 254bf115..2ee71072 100644
--- a/v2rayN/v2rayN/HttpProxyHandler/ProxySetting.cs
+++ b/v2rayN/v2rayN/HttpProxyHandler/ProxySetting.cs
@@ -128,7 +128,7 @@ namespace v2rayN.HttpProxyHandler
             public InternetConnectionOptionValue m_Value;
             static InternetConnectionOption()
             {
-                InternetConnectionOption.Size = Marshal.SizeOf(typeof(InternetConnectionOption));
+                Size = Marshal.SizeOf(typeof(InternetConnectionOption));
             }
 
             // Nested Types
diff --git a/v2rayN/v2rayN/Program.cs b/v2rayN/v2rayN/Program.cs
index 3d57be50..bd6e36d3 100644
--- a/v2rayN/v2rayN/Program.cs
+++ b/v2rayN/v2rayN/Program.cs
@@ -46,7 +46,7 @@ namespace v2rayN
 
                 //设置语言环境
                 string lang = Utils.RegReadValue(Global.MyRegPath, Global.MyRegKeyLanguage, "zh-Hans");
-                System.Threading.Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(lang);
+                Thread.CurrentThread.CurrentUICulture = new System.Globalization.CultureInfo(lang);
 
                 Application.EnableVisualStyles();
                 Application.SetCompatibleTextRenderingDefault(false);
diff --git a/v2rayN/v2rayN/Tool/Utils.cs b/v2rayN/v2rayN/Tool/Utils.cs
index bbca80c8..f6f0bb3c 100644
--- a/v2rayN/v2rayN/Tool/Utils.cs
+++ b/v2rayN/v2rayN/Tool/Utils.cs
@@ -124,7 +124,7 @@ namespace v2rayN
             int result = -1;
             try
             {
-                using (StreamWriter file = System.IO.File.CreateText(filePath))
+                using (StreamWriter file = File.CreateText(filePath))
                 {
                     //JsonSerializer serializer = new JsonSerializer();
                     JsonSerializer serializer = new JsonSerializer() { Formatting = Formatting.Indented };
@@ -194,7 +194,7 @@ namespace v2rayN
         {
             try
             {
-                byte[] plainTextBytes = System.Text.Encoding.UTF8.GetBytes(plainText);
+                byte[] plainTextBytes = Encoding.UTF8.GetBytes(plainText);
                 return Convert.ToBase64String(plainTextBytes);
             }
             catch (Exception ex)
@@ -364,7 +364,7 @@ namespace v2rayN
         {
             try
             {
-                int var1 = Utils.ToInt(oText);
+                int var1 = ToInt(oText);
                 return true;
             }
             catch
@@ -533,7 +533,7 @@ namespace v2rayN
         public static string GetPath(string fileName)
         {
             string startupPath = StartupPath();
-            if (Utils.IsNullOrEmpty(fileName))
+            if (IsNullOrEmpty(fileName))
             {
                 return startupPath;
             }
@@ -833,7 +833,7 @@ namespace v2rayN
                         sb.Write(buffer, 0, n);
                     }
                 }
-                return System.Text.Encoding.UTF8.GetString(sb.ToArray());
+                return Encoding.UTF8.GetString(sb.ToArray());
             }
         }