diff --git "a/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214.sln" "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214.sln"
new file mode 100644
index 0000000000000000000000000000000000000000..15f4648b61b8c33085cd1aabc00f0a2cd7290a78
--- /dev/null
+++ "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214.sln"
@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.30011.22
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "日期和", "日期和\日期和.csproj", "{CD09BEA2-D2C2-4065-A3DC-FE17D058C909}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{CD09BEA2-D2C2-4065-A3DC-FE17D058C909}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CD09BEA2-D2C2-4065-A3DC-FE17D058C909}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CD09BEA2-D2C2-4065-A3DC-FE17D058C909}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CD09BEA2-D2C2-4065-A3DC-FE17D058C909}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {350FC1F3-910B-48F5-8543-96D033F6A3A9}
+	EndGlobalSection
+EndGlobal
diff --git "a/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/Program.cs" "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/Program.cs"
new file mode 100644
index 0000000000000000000000000000000000000000..3657b2db61d4e7cc17ba320c7e3e9635fa01a4e7
--- /dev/null
+++ "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/Program.cs"
@@ -0,0 +1,95 @@
+using System;
+using System.Linq;
+using System.Net.Sockets;
+using System.Xml;
+
+namespace 日期和
+{
+    class Program
+    {
+        static void Main(string[] args)
+        {
+            //日期
+            DateTime dt = DateTime.Now;
+
+            Console.WriteLine("现在是{0}年",dt.Year);
+            Console.WriteLine("现在是{0}年,{1}月",dt.Year,dt.Month);
+            Console.WriteLine("现在是{0}年,{1}月,{2}日",dt.Year,dt.Month,dt.Day);
+
+
+            //Length
+            string str = Console.ReadLine();
+            Console.WriteLine("字符串的长度为:"+ str.Length);
+            Console.WriteLine("字符串中第一个字符为:"+str[0]);
+            Console.WriteLine("字符串中最后一个字符为:"+str[str.Length-1]);
+
+            string str1 = Console.ReadLine();
+            for (int i = str1.Length - 1; i >= 0; i--)
+            {
+                    Console.WriteLine(str1[i]);
+             }
+
+            //IndexOf和LastIndexOf
+            string str2 = Console.ReadLine();
+            if (str2.IndexOf("@")== -1)
+            {
+                Console.WriteLine("字符串中没有@");
+            }
+            else
+            {
+                Console.WriteLine("字符串中有@,出现的位置是:{0}",str2.IndexOf("@")+1);
+            }
+
+            string str3 = Console.ReadLine();
+            int First = str3.IndexOf("@");
+            int Last = str3.LastIndexOf("@");
+            if (First != -1)
+            {
+                if (First == Last)
+                {
+                    Console.WriteLine("在此字符串中仅有一个@");
+                }
+                else
+                {
+                    Console.WriteLine("此字符串中有多个@");
+                }
+            }
+            else
+            {
+                Console.WriteLine("字符串中没哟@");
+            }
+
+            //Replace：字符串替换函
+            string str4 = Console.ReadLine();
+            if(str4.IndexOf(",")!=-1)
+            {
+                str4 = str4.Replace(",", "~");
+            }
+
+
+            // Substring：字符串截取函数
+            string str5 = Console.ReadLine();
+            int First1 = str5.IndexOf("@");
+            str5 = str5.Substring(0, First1);
+            Console.WriteLine("邮箱中的用户名是:"+str5);
+
+            //insert 插入字符串
+            string str6 = Console.ReadLine();
+            str = str.Insert(1, "@@@");
+            Console.WriteLine("新字符串为：" + str);
+
+            //替换
+            string re = Console.ReadLine();
+            re = re.Replace(",", ".");
+            Console.WriteLine(re);
+
+            Console.WriteLine("请输入你的证件号：");
+            string man = Console.ReadLine();
+            Console.WriteLine("你的出生年月为：");
+            man = man.Substring(6,8);
+            Console.WriteLine(man);
+
+
+        }
+    }
+}
diff --git "a/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/\346\227\245\346\234\237\345\222\214.csproj" "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/\346\227\245\346\234\237\345\222\214.csproj"
new file mode 100644
index 0000000000000000000000000000000000000000..d453e9a07115e38f587d8e299b4fc2d68f0f4d74
--- /dev/null
+++ "b/\345\210\230\346\263\242/\346\227\245\346\234\237\345\222\214/\346\227\245\346\234\237\345\222\214.csproj"
@@ -0,0 +1,8 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+  </PropertyGroup>
+
+</Project>