.NET反射技术使用例子

获得实例的方法
1.获得同一程序集内的类型的实例。 

无参数构造函数
                Type t = Type.GetType("AppCode.Employe");

                if (t == null)
                {
                    textBox1.Text = "Create Type Error";
                    return;
                }

                object emp = t.Assembly.CreateInstance("AppCode.Employe");

                if (emp == null)
                {
                    textBox1.Text = "Create Instance Error";
                    return;
                }

                StringBuilder sb = new StringBuilder();
                sb.AppendLine("Type:" + t.FullName);
                sb.AppendLine("Context:");
                sb.AppendLine(emp.ToString());

                textBox1.Text = sb.ToString();

 

有参数构造函数
               Type t = Type.GetType("AppCode.Employe");

                if (t == null)
                {
                    textBox1.Text = "Create Type Error";
                    return;
                }

                //构造函数参数列表如下
                  //public Employe(string userid, string username, int age)

                //生成参数类型数组
                  Type[] ts = new Type[3] { typeof(System.String),typeof(System.String), typeof(System.Int16) };

                //获得构造函数
                  ConstructorInfo mi = t.GetConstructor(ts);

                if (mi == null)
                {
                    textBox1.Text = "Create ConstructorInfo Error";
                    return;
                }

                //生成参数值数组
                object[] ps=new object[3];
                ps[0] = "420106780911326";
                ps[1] = "wesker";
                ps[2] = 36;

                object emp=mi.Invoke(ps);

                StringBuilder sb = new StringBuilder();
                sb.AppendLine("Type:" + t.FullName);
                sb.AppendLine("Context:");
                sb.AppendLine(emp.ToString());

                textBox1.Text = sb.ToString();

2.获得不同程序集内的类型的实例。
比如当前窗体程序要通过反射获得一个名为"compenent1"（文件名为compenent1.dll）的程序集中的类型的实例。

无参数构造函数
                Type t = Assembly.LoadFile(AppDomain.CurrentDomain.BaseDirectory + "\\compenent1.dll").
                    GetType("compenent1.User");

                if (t == null)
                {
                    textBox1.Text = "Create Type Error";
                    return;
                }

                object user = t.Assembly.CreateInstance("compenent1.User");

                if (user == null)
                {
                    textBox1.Text = "Create Instance Error";
                    return;
                }

                StringBuilder sb = new StringBuilder();
                sb.AppendLine("Type:" + t.FullName);
                sb.AppendLine("Context:");
                sb.AppendLine(user.ToString());

                textBox1.Text = sb.ToString();

 

有参数的构造函数
                Type t = Assembly.LoadFile(AppDomain.CurrentDomain.BaseDirectory + "\\compenent1.dll").
                    GetType("compenent1.User");

                if (t == null)
                {
                    textBox1.Text = "Create Type Error";
                    return;
                }

                   //构造函数参数列表如下
               //public Employe(string userid, string username, int age)

                Type[] ts = new Type[3] { typeof(System.String), typeof(System.String), typeof(System.Int16) };

                ConstructorInfo mi = t.GetConstructor(ts);

                if (mi == null)
                {
                    textBox1.Text = "Create ConstructorInfo Error";
                    return;
                }

                object[] ps = new object[3];
                ps[0] = "420106780911326";
                ps[1] = "wesker";
                ps[2] = 36;

                object user = mi.Invoke(ps);

                StringBuilder sb = new StringBuilder();
                sb.AppendLine("Type:" + t.FullName);
                sb.AppendLine("Context:");
                sb.AppendLine(user.ToString());

                textBox1.Text = sb.ToString();

3.使用反射调用方法

                Type t = Type.GetType("AppCode.Employe");

                if (t == null)
                {
                    textBox1.Text = "Create Type Error";
                    return;
                }

                object emp = t.Assembly.CreateInstance("AppCode.Employe");

                if (emp == null)
                {
                    textBox1.Text = "Create Instance Error";
                    return;
                }

                MethodInfo mi = t.GetMethod("ToString");
                string context = mi.Invoke(emp,null).ToString();

                StringBuilder sb = new StringBuilder();
                
                sb.AppendLine("Context:");
                sb.AppendLine(context);
                sb.AppendLine("Type:" + t.FullName);

                textBox1.Text = sb.ToString();

4.获得类的信息
通过Type.GetMethods方法获得方法的信息。
通过Type.GetConstructors获得构造函数。

5.使用Activator类实例化类型

            Type t = Type.GetType("AppCode.TempEmploye");

            if (t == null)
            {
                textBox1.Text = "Create Type Error";
                return;
            }

            object[] ps = new object[4];
            ps[0] = "420106780911326";
            ps[1] = "wesker";
            ps[2] = 36;
            ps[3] = "temp123";

            object o = Activator.CreateInstance(t, ps);

            if (o == null)
            {
                textBox1.Text = "Create Instance Error";
                return;
            }

            StringBuilder sb = new StringBuilder();
            sb.AppendLine("Type:" + t.FullName);
            sb.AppendLine("Context:");
            sb.AppendLine(o.ToString());

            textBox1.Text = sb.ToString();