264700-How to lock or protect certain cells of Excel file in c#, vb.net

Use Cases/Lock cells in worksheet/.NET/Lock cells in worksheet/Lock cells in worksheet.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.14.36127.28 d17.14
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lock cells in worksheet", "Lock cells in worksheet\Lock cells in worksheet.csproj", "{3EBFBBB9-0A14-4886-929C-4FB78EB16777}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{3EBFBBB9-0A14-4886-929C-4FB78EB16777}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3EBFBBB9-0A14-4886-929C-4FB78EB16777}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3EBFBBB9-0A14-4886-929C-4FB78EB16777}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3EBFBBB9-0A14-4886-929C-4FB78EB16777}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {30267131-B722-4B00-8233-EC03587B9AB8}
+	EndGlobalSection
+EndGlobal

Use Cases/Lock cells in worksheet/.NET/Lock cells in worksheet/Lock cells in worksheet/Lock cells in worksheet.csproj

@@ -0,0 +1,23 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <RootNamespace>Lock_cells_in_worksheet</RootNamespace>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Syncfusion.XlsIO.Net.Core" Version="*" />
+  </ItemGroup>
+
+  <ItemGroup>
+	<None Update="Data\*">
+		<CopyToOutputDirectory>Always</CopyToOutputDirectory>
+	</None>
+	<None Update="Output\*">
+		<CopyToOutputDirectory>Always</CopyToOutputDirectory>
+	</None>
+  </ItemGroup>
+</Project>

Use Cases/Lock cells in worksheet/.NET/Lock cells in worksheet/Lock cells in worksheet/Program.cs

@@ -0,0 +1,38 @@
+using Syncfusion.XlsIO;
+
+namespace Lock_Cells_In_Worksheet
+{
+    class Program
+    {
+        public static void Main(string[] args)
+        {
+            using (ExcelEngine excelEngine = new ExcelEngine())
+            {
+                IApplication application = excelEngine.Excel;
+                application.DefaultVersion = ExcelVersion.Xlsx;
+                FileStream inputStream = new FileStream(Path.GetFullPath(@"Data/InputData.xlsx"), FileMode.Open, FileAccess.ReadWrite);
+                IWorkbook workbook = application.Workbooks.Open(inputStream);
+                IWorksheet worksheet = workbook.Worksheets[0];
+
+                //Unlock cells in the worksheet
+                worksheet.UsedRange.CellStyle.Locked = false; 
+
+                //Lock specific cells (A1:A5)
+                worksheet.Range["A1:A5"].CellStyle.Locked = true;
+
+                //Protect worksheet to apply lock
+                worksheet.Protect("password", ExcelSheetProtection.All);
+
+                #region Save
+                //Saving the workbook
+                FileStream outputStream = new FileStream(Path.GetFullPath("LockedCells.xlsx"), FileMode.Create, FileAccess.Write);
+                workbook.SaveAs(outputStream);
+                #endregion
+
+                //Dispose streams
+                outputStream.Dispose();
+                inputStream.Dispose();
+            }
+        }
+    }
+}