标签：des blog io ar 使用 sp 数据 div on
使用System.Reflection.Emit+Code First model创建以下的一个实体类和DbContext并且创建数据库:
1 using System;
2
3 public class Blog
4
5 {
6
7 private int id;
8
9 private string name;
10
11 public int ID
12
13 {
14
15 get
16
17 {
18
19 return this.id;
20
21 }
22
23 set
24
25 {
26
27 this.id = value;
28
29 }
30
31 }
32
33 public string Name
34
35 {
36
37 get
38
39 {
40
41 return this.name;
42
43 }
44
45 set
46
47 {
48
49 this.name = value;
50
51 }
52
53 }
54
55 }
using System;
using System.Data.Entity;
public class Sample20141106 : DbContext
{
private DbSet<Blog> blogs;
public DbSet<Blog> Blogs
{
get
{
return this.blogs;
}
set
{
this.blogs = value;
}
}
}
1.创建类所在的程序集合module:
AppDomain myDomain = Thread.GetDomain();
AssemblyName myAsmName = new AssemblyName();
myAsmName.Name = "Sample20141106";
// To generate a persistable assembly, specify AssemblyBuilderAccess.RunAndSave.
ssemblyBuilder myAsmBuilder = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.RunAndSave);
// Generate a persistable single-module assembly.
ModuleBuilder myModBuilder = myAsmBuilder.DefineDynamicModule(myAsmName.Name, myAsmName.Name + ".dll");
2.创建Blog实体类:
创建类型:
TypeBuilder BlogTypeBuilder = myModBuilder.DefineType("Blog", TypeAttributes.Public);
创建ID和Name properties:（这个应该可以考虑写成同样方法，传入类型和类型名称）
FieldBuilder idBldr = BlogTypeBuilder.DefineField("id", typeof(int), FieldAttributes.Private);
FieldBuilder nameBldr = BlogTypeBuilder.DefineField("name", typeof(string), FieldAttributes.Private);
PropertyBuilder idPropBldr = BlogTypeBuilder.DefineProperty("ID", PropertyAttributes.HasDefault, typeof(int), null);
PropertyBuilder namePropBldr = BlogTypeBuilder.DefineProperty("Name", PropertyAttributes.HasDefault, typeof(string), null);
MethodAttributes getSetAttr = MethodAttributes.Public | MethodAttributes.SpecialName | MethodAttributes.HideBySig;
MethodBuilder idGetPropMthdBldr = BlogTypeBuilder.DefineMethod("get_ID", getSetAttr, typeof(int), Type.EmptyTypes);
ILGenerator idGetIL = idGetPropMthdBldr.GetILGenerator();
idGetIL.Emit(OpCodes.Ldarg_0);
idGetIL.Emit(OpCodes.Ldfld, idBldr);
idGetIL.Emit(OpCodes.Ret);
MethodBuilder idSetPropMthdBldr = BlogTypeBuilder.DefineMethod("set_ID", getSetAttr, null, new Type[] { typeof(int) });
ILGenerator idSetIL = idSetPropMthdBldr.GetILGenerator();
idSetIL.Emit(OpCodes.Ldarg_0);
idSetIL.Emit(OpCodes.Ldarg_1);
idSetIL.Emit(OpCodes.Stfld, idBldr);
idSetIL.Emit(OpCodes.Ret);
idPropBldr.SetGetMethod(idGetPropMthdBldr);
idPropBldr.SetSetMethod(idSetPropMthdBldr);
MethodBuilder nameGetPropMthdBldr = BlogTypeBuilder.DefineMethod("get_Name", getSetAttr, typeof(int), Type.EmptyTypes);
ILGenerator nameGetIL = nameGetPropMthdBldr.GetILGenerator();
nameGetIL.Emit(OpCodes.Ldarg_0);
nameGetIL.Emit(OpCodes.Ldfld, nameBldr);
nameGetIL.Emit(OpCodes.Ret);
MethodBuilder nameSetPropMthdBldr = BlogTypeBuilder.DefineMethod("set_Name", getSetAttr, null, new Type[] { typeof(int) });
ILGenerator nameSetIL = nameSetPropMthdBldr.GetILGenerator();
nameSetIL.Emit(OpCodes.Ldarg_0);
nameSetIL.Emit(OpCodes.Ldarg_1);
nameSetIL.Emit(OpCodes.Stfld, nameBldr);
nameSetIL.Emit(OpCodes.Ret);
namePropBldr.SetGetMethod(nameGetPropMthdBldr);
namePropBldr.SetSetMethod(nameSetPropMthdBldr);
生成类型到内存中,这个类型在后面生成DbContext有用
Type blogType = BlogTypeBuilder.CreateType();
2.创建DbContxt类型:
构造类型:
TypeBuilder Sample20141106TypeBuilder = myModBuilder.DefineType("Sample20141106", TypeAttributes.Public);
Sample20141106TypeBuilder.SetParent(typeof(DbContext));//生成的类型继承DbContext, 在生成程序集的时候会自动引用EntiyFrame.dll.
构造DbSet<T>属性:
FieldBuilder blogFieldBuilder = Sample20141106TypeBuilder.DefineField("blogs", typeof(DbSet<>).MakeGenericType(blogType), FieldAttributes.Private);
PropertyBuilder blogPropBldr = Sample20141106TypeBuilder.DefineProperty("Blogs", PropertyAttributes.HasDefault, typeof(DbSet<>).MakeGenericType(blogType), null);
MethodBuilder blogGetPropMthdBldr = Sample20141106TypeBuilder.DefineMethod("get_Blog", getSetAttr, typeof(DbSet<>).MakeGenericType(blogType), Type.EmptyTypes);
ILGenerator blogGetIL = blogGetPropMthdBldr.GetILGenerator();
blogGetIL.Emit(OpCodes.Ldarg_0);
blogGetIL.Emit(OpCodes.Ldfld, blogFieldBuilder);
blogGetIL.Emit(OpCodes.Ret);
MethodBuilder blogSetPropMthdBldr = Sample20141106TypeBuilder.DefineMethod("set_Blog", getSetAttr, null, new Type[] { typeof(DbSet<>).MakeGenericType(blogType) });
ILGenerator blogSetIL = blogSetPropMthdBldr.GetILGenerator();
blogSetIL.Emit(OpCodes.Ldarg_0);
blogSetIL.Emit(OpCodes.Ldarg_1);
blogSetIL.Emit(OpCodes.Stfld, blogFieldBuilder);
blogSetIL.Emit(OpCodes.Ret);
blogPropBldr.SetGetMethod(blogGetPropMthdBldr);
blogPropBldr.SetSetMethod(blogSetPropMthdBldr);
生成DbContext类型到内存:
Type Sample20141106Type = Sample20141106TypeBuilder.CreateType();
可以选择将模型保存到dll中:
myAsmBuilder.Save(myAsmName.Name + ".dll");
然后可以在其他project中引用。或者用反射直接生成数据库:
Type Sample20141106 = BuildDynamicTypeWithProperties();
object db = Activator.CreateInstance(Sample20141106);
Type Database = Sample20141106.GetProperty("Database").GetValue(db).GetType();
object database = Sample20141106.GetProperty("Database").GetValue(db);
MethodInfo CreateIfNotExists = Database.GetMethod("CreateIfNotExists");
CreateIfNotExists.Invoke(database, null);
EntityFramework动态创建模型：System.Reflection.Emit + Code First
标签：des blog io ar 使用 sp 数据 div on
原文地址：http://www.cnblogs.com/fred-bao/p/4083504.html
