C# 通過反射獲取類型的字段值及給字段賦值的操作
舉例：
存在一個類：
Public Class Student
{
public string name;
public int age;
}
Student stu1 = new Student();
現在，我們想通過反射在運行時給stu1的name 和 age字段 賦值，讓name = “小明”,age = 15，怎麼做?
簡單的代碼如下:
...略
using System.Reflection;//反射類
...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);
}
需要註意的是:FieldInfo的SetValue方法有可能會導致異常，比如 fieldInfo2.SetValue(stu1,“15”)，這句話給一個int型字段賦瞭string類型的值，編譯是不會報錯的，在運行時會拋出一個System.ArgumentException異常，請多加註意.
有瞭以上的瞭解，讓我們寫一個簡單的動態字段賦值/取值類Dynamic
具體代碼如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Reflection;
namespace MyUnityHelper
{
/// <summary>
/// 動態編譯類
/// </summary>
public class Dynamic
{
/// <summary>
/// 動態賦值
/// </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>
/// 泛型動態賦值
/// </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>
/// 動態取值
/// </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>
/// 動態取值泛型
/// </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);
}
}
}
補充：C#利用反射方法實現對象的字段和屬性之間值傳遞
在面向對象開發過程中，往往會遇到兩個對象之間進行值傳遞的情況，如果對象中的屬性和字段較多，手動一一賦值效率實在太低。
這裡就整理瞭一個通用的對象之間進行值傳遞的方法，並且考慮到對象中可能包含類屬性，因此還用到瞭遞歸以解決這個問題。
下面上代碼：
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}");
}
}
}
以上為個人經驗，希望能給大傢一個參考，也希望大傢多多支持WalkonNet。如有錯誤或未考慮完全的地方，望不吝賜教。