C creates the implementation method of the type dynamically at run time

This article's example shows how C# implements the dynamic creation of a type at run time. Is a useful skill for C# project development. Share to everybody for everybody reference. The specific analysis is as follows:

Specifically, C# dynamically creates types at run time by dynamically generating C# source code, which is then compiled into assemblies by the compiler.

The main function codes are as follows:

public static Assembly NewAssembly()
{
  // Create a compiler instance.   
  provider = new CSharpCodeProvider();
  // Set compilation parameters.   
  cp = new CompilerParameters();
  cp.GenerateExecutable = false;
  cp.GenerateInMemory = true;

  // Generate an executable instead of 
  // a class library.
  //cp.GenerateExecutable = true;

  // Set the assembly file name to generate.
  cp.OutputAssembly = "c:\\1.dll";

  // Generate debug information.
  cp.IncludeDebugInformation = true;


  // Save the assembly as a physical file.
  cp.GenerateInMemory = false;

  // Set the level at which the compiler 
  // should start displaying warnings.
  cp.WarningLevel = 3;

  // Set whether to treat all warnings as errors.
  cp.TreatWarningsAsErrors = false;

  // Set compiler argument to optimize output.
  cp.CompilerOptions = "/optimize";

  cp.ReferencedAssemblies.Add("System.dll");
  //cp.ReferencedAssemblies.Add("System.Core.dll");
  cp.ReferencedAssemblies.Add("System.Data.dll");
  //cp.ReferencedAssemblies.Add("System.Data.DataSetExtensions.dll");
  cp.ReferencedAssemblies.Add("System.Deployment.dll");
  cp.ReferencedAssemblies.Add("System.Design.dll");
  cp.ReferencedAssemblies.Add("System.Drawing.dll");
  cp.ReferencedAssemblies.Add("System.Windows.Forms.dll");

  // Create dynamic code.   
  
  StringBuilder classSource = new StringBuilder();
  classSource.Append("using System;using System.Windows.Forms;\npublic  class  DynamicClass: UserControl \n");
  classSource.Append("{\n");
  classSource.Append("public DynamicClass()\n{\nInitializeComponent();\nConsole.WriteLine(\"hello\");}\n");
  classSource.Append( "private System.ComponentModel.IContainer components = null;\nprotected override void Dispose(bool disposing)\n{\n");
  classSource.Append( "if (disposing && (components != null)){components.Dispose();}base.Dispose(disposing);\n}\n");
  classSource.Append( "private void InitializeComponent(){\nthis.SuspendLayout();this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);");
  classSource.Append( "this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;this.Name = \"DynamicClass\";this.Size = new System.Drawing.Size(112, 74);this.ResumeLayout(false);\n}");
  // Create properties.   
  /************************* I'm going to change the properties that I want here ******************************/
  classSource.Append(propertyString("aaa"));
  classSource.Append(propertyString("bbb"));
  classSource.Append(propertyString("ccc"));

  classSource.Append("}");

  System.Diagnostics.Debug.WriteLine(classSource.ToString());
 
  // Compile the code.   
  CompilerResults result = provider.CompileAssemblyFromSource(cp, classSource.ToString());
  if (result.Errors.Count > 0)
  {
 for( int i = 0; i < result.Errors.Count; i ++)
   Console.WriteLine(result.Errors[ i]);
 Console.WriteLine("error");
 return null;
  }
  
  // Gets the compiled assembly.   
  Assembly assembly = result.CompiledAssembly;

  return assembly;
}

private static string propertyString(string propertyName)
{
  StringBuilder sbProperty = new StringBuilder();
  sbProperty.Append(" private  int  _" + propertyName + "  =  0;\n");
  sbProperty.Append(" public  int  " + "" + propertyName + "\n");
  sbProperty.Append(" {\n");
  sbProperty.Append(" get{  return  _" + propertyName + ";}  \n");
  sbProperty.Append(" set{  _" + propertyName + "  =  value;  }\n");
  sbProperty.Append(" }");
  return sbProperty.ToString();
}

Hopefully this article has helped you with your C# programming