举例:
存在一个类:
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Public Class Student { public string name; public int age; } Student stu1 = new Student(); |
现在,我们想通过反射在运行时给stu1的name 和 age字段 赋值,让name = “小明”,age = 15,怎么做?
简单的代码如下:
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...略 using System.Reflection; //反射类 ...略 static void Main( string [] args) { Type t = stu1.GetType(); FieldInfo filedInfo1 = t.GetField(”name"); FieldInfo filedInfo2 = t.GetField(”age"); fieldInfo1.SetValue(stu1, "小明" ); fieldInfo2.SetValue(stu1,15); } |
需要注意的是:FieldInfo的SetValue方法有可能会导致异常,比如 fieldInfo2.SetValue(stu1,“15”),这句话给一个int型字段赋了string类型的值,编译是不会报错的,在运行时会抛出一个System.ArgumentException异常,请多加注意.
有了以上的了解,让我们写一个简单的动态字段赋值/取值类Dynamic
具体代码如下:
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using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Reflection; namespace MyUnityHelper { /// <summary> /// 动态编译类 /// </summary> public class Dynamic { /// <summary> /// 动态赋值 /// </summary> /// <param name="obj"></param> /// <param name="fieldName"></param> /// <param name="value"></param> public static void SetValue( object obj, string fieldName, object value) { FieldInfo info = obj.GetType().GetField(fieldName); info.SetValue(obj, value); } /// <summary> /// 泛型动态赋值 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="obj"></param> /// <param name="fieldName"></param> /// <param name="value"></param> public static void SetValue<T>( object obj, string fieldName, T value) { FieldInfo info = obj.GetType().GetField(fieldName); info.SetValue(obj, value); } /// <summary> /// 动态取值 /// </summary> /// <param name="obj"></param> /// <param name="fieldName"></param> /// <returns></returns> public static object GetValue( object obj, string fieldName) { FieldInfo info = obj.GetType().GetField(fieldName); return info.GetValue(obj); } /// <summary> /// 动态取值泛型 /// </summary> /// <typeparam name="T"></typeparam> /// <param name="obj"></param> /// <param name="fieldName"></param> /// <returns></returns> public static T GetValue<T>( object obj, string fieldName) { FieldInfo info = obj.GetType().GetField(fieldName); return (T)info.GetValue(obj); } } } |
补充:C#利用反射方法实现对象的字段和属性之间值传递
在面向对象开发过程中,往往会遇到两个对象之间进行值传递的情况,如果对象中的属性和字段较多,手动一一赋值效率实在太低。
这里就整理了一个通用的对象之间进行值传递的方法,并且考虑到对象中可能包含类属性,因此还用到了递归以解决这个问题。
下面上代码:
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public static void ConvertObject( object SrcClass, object DesClass, bool convertProperty = true , bool convertField = true , bool showError = true ) { try { if (SrcClass == null ) { return ; } if (convertProperty) { PropertyInfo[] srcProperties = SrcClass.GetType().GetProperties(); PropertyInfo[] desProperties = DesClass.GetType().GetProperties(); if (srcProperties.Length > 0 && desProperties.Length > 0) { foreach (var srcPi in srcProperties) { foreach (var desPi in desProperties) { if (srcPi.Name == desPi.Name && srcPi.PropertyType == desPi.PropertyType && desPi.CanWrite) { if (srcPi.PropertyType.IsClass) { ConvertObject(srcPi.GetValue(SrcClass, null ), desPi.GetValue(DesClass, null ), convertProperty, convertField, showError); } else { Object value = srcPi.GetValue(SrcClass, null ); desPi.SetValue(DesClass, value, null ); } } } } } } if (convertField) { FieldInfo[] srcFields = SrcClass.GetType().GetFields(); FieldInfo[] desFields = DesClass.GetType().GetFields(); if (srcFields.Length > 0 && desFields.Length > 0) { foreach (var srcField in srcFields) { foreach (var desField in desFields) { if (srcField.Name == desField.Name && srcField.FieldType == desField.FieldType) { if (srcField.FieldType.IsClass) { ConvertObject(srcField.GetValue(SrcClass), desField.GetValue(DesClass), convertProperty, convertField, showError); } else { Object value = srcField.GetValue(SrcClass); desField.SetValue(DesClass, value); } } } } } } } catch (Exception ex) { if (showError) { MessageBox.Show($ "Convert Error: Method={nameof(ConvertObject)}, Message={ex.Message}" ); } else { throw new Exception($ "Convert Error: Method={nameof(ConvertObject)}, Message={ex.Message}" ); } } } |
以上为个人经验,希望能给大家一个参考,也希望大家多多支持服务器之家。如有错误或未考虑完全的地方,望不吝赐教。
原文链接:https://blog.csdn.net/qq_40693302/article/details/98961669