C # Reflection (PropertyInfo Class)

1. Introduction of namespaces: System.Reflection; Assembly: mscorlib (in mscorlib.dll)

2. Sample code (mainly GetType (), SetValue (), GetValue () method):

1UsingSystem;2UsingSystem.Collections.Generic;3UsingSystem.Linq;4UsingSystem.Reflection;5UsingSystem.Text;6UsingSystem.Threading.Tasks;78NamespaceReflection9{10ClassProgram11{12///<summary>13///Reflection describes assemblies, modules, types of objects (type types). You can use reflection to dynamically create an instance of a type, bind an instance to an existing object, or get a type from an existing object and call its methods or access its fields and properties14///If you use attributes in your code, you can use reflection to access them15///</summary>16Staticvoid Main (String[] args)17{1819//1. Explanations and examples of GetType ()20//21st//Summary:22//Gets the System.Type of the current instance.23//24//return Result:25//An System.Type instance that represents the exact run-time type of the current instance.2627//The following example obtains a simple reflection of its type using the static method gettype (all types derived from the object base class inherit the method)Student STU1 =New Student () {id =1, name ="Tom", length =175, DateTime = DateTime.Now};//Student STU2 =New Student () {id =2, name ="John doe", length =, DateTime = DateTime.Now};//name = "John Doe", DateTime = DateTime.Now3031var list =New list<student>();32List. ADD (STU1);33List. ADD (STU2);34Type Stutype =Stu1. GetType ();Type ListType =List. GetType ();37Console.WriteLine ("---------------getType () output Type----------------");Console.WriteLine (Stutype);//Type of output studentConsole.WriteLine (Stu1.id.GetType ());//Type of ID for output studentConsole.WriteLine (Stu1.name.GetType ());//Type of the name of the output studentConsole.WriteLine (Stu1.datetime.GetType ());//Type of datetime for output student43Console.WriteLine (ListType);//Type of output list454647//2. Explanations and examples of GetProperties ()48//49//Summary:50//Returns all the public properties of the current System.Type.51//52//return Result:53//An array of System.Reflection.PropertyInfo objects that represent all the public properties of the current System.Type. -or-if the current System.Type54//An empty array of type SYSTEM.REFLECTION.PROPERTYINFO without a public property.55propertyinfo[] Stupropertys =Stutype.getproperties ();propertyinfo[] Listpropertys =Listtype.getproperties ();5859//Console.WriteLine (Stupropertys.count ());60//Console.WriteLine (Stupropertys.length);6162//3. Explanations and examples of SetValue ()63//64//Summary:65//Sets the value of the property with an optional index value for the indexed property.66//67//Parameters:68//Obj:69//The object whose property values will be set.70//71//Value72//The new value for this property.73//74//Index 75//The optional index value of the indexed property. For a non-indexed property, this value should be null. 76//77//Exception: system.argumentexception:79/////The index array does not contain parameters of the required type. -or-the property's set accessor was not found. +//Bayi//system.reflection.targetexception:82//The object does not match the target type, or an attribute is an instance property but obj is null. SYSTEM.REFLECTION.TARGETPARAMETERCOUNTEXCEPTION:85//+///////-The number of parameters in index does not match the number of parameters used by indexed properties. +/////system.methodaccessexception:88//try to access private or protected methods in a class illegally. system.reflection.targetinvocationexception:91////////////////////// For example, the index value specified for an indexed property is out of range. The System.Exception.InnerException property indicates the cause of the error. The Console.WriteLine ("---------------SetValue () assigns a value to a property----------------"); PropertyInfo Stupro = stupropertys.firstordefault (x = X.name = = "Name");//Here is the property name for name 94 Stupro.setvalue (STU1, "King Five ", null); Console.WriteLine (Stu1.name); 96 97 98//4, GetType () method explanation and Example 99//100//Abstract: 101//Returns the property value of the specified object with an optional index value for the indexed property. 102//103//Parameter: 104//OBJ:105//The object whose property value will be returned. 106 the optional index value of the//107//index:108//indexed property. For a non-indexed property, the value should be null. 109//110//Return Result: 111//Specify the property value of the object. 112//113//exception: 114//system.argumentexception:115//The index array does not contain the parameters of the desired type. -or-the get accessor for the property was not found. //117//system.reflection.targetexception:118//The object does not match the target type, or an attribute is an instance property but obj is null. 119//120//system.reflection.targetparametercountexception:121//Index The number of parameters in the index does not match the number of parameters used by the indexed property. 122//123//system.methodaccessexception:124//attempt to illegally access a private or protected method in a class. //126//system.reflection.targetinvocationexception:127//Error retrieving property value. For example, the index value specified for an indexed property is out of range. The System.Exception.InnerException property indicates the cause of the error. Console.WriteLine ("---------------getValue () Traverse property Value----------------"), 129 foreach (Var v in stupropertys)//Traverse Property 130 {131 Console.WriteLine (V.getvalue (STU1, null));}133 134 135 console.readline (); 136}137}138 139 public class Student1 {141 public int id {get; set;} 142 public string Name {get; set;} 143 public decimal Length {get; set;} 144 public datetime datetime {get; set;} 145}146}

3. Operation Result:

4. The following are the main public members of the PropertyInfo type, for reference (excerpt from: Http://msdn.microsoft.com/zh-cn/library/system.reflection.propertyinfo (v= vs.110). aspx)

C # Reflection (PropertyInfo Class)