代码改变世界

在 C#,快速复制一个对象的值给另一个对象(常常用于父类与子类之间相互复制)

2011-09-15 21:04  音乐让我说  阅读(2919)  评论(0编辑  收藏  举报

直接贴代码了:

using System;
using System.Collections.Generic;
using System.ComponentModel;

public static class ModelCopier
{
    public static void CopyCollection<T>(IEnumerable<T> from, ICollection<T> to) {
        if (from == null || to == null || to.IsReadOnly) {
            return;
        }

        to.Clear();
        foreach (T element in from) {
            to.Add(element);
        }
    }

    public static void CopyModel(object from, object to) {
        if (from == null || to == null) {
            return;
        }

        PropertyDescriptorCollection fromProperties = TypeDescriptor.GetProperties(from);
        PropertyDescriptorCollection toProperties = TypeDescriptor.GetProperties(to);

        foreach (PropertyDescriptor fromProperty in fromProperties) {
            PropertyDescriptor toProperty = toProperties.Find(fromProperty.Name, true /* ignoreCase */);
            if (toProperty != null && !toProperty.IsReadOnly) {
                // Can from.Property reference just be assigned directly to to.Property reference?
                bool isDirectlyAssignable = toProperty.PropertyType.IsAssignableFrom(fromProperty.PropertyType);
                // Is from.Property just the nullable form of to.Property?
                bool liftedValueType = (isDirectlyAssignable) ? false : (Nullable.GetUnderlyingType(fromProperty.PropertyType) == toProperty.PropertyType);

                if (isDirectlyAssignable || liftedValueType) {
                    object fromValue = fromProperty.GetValue(from);
                    if (isDirectlyAssignable || (fromValue != null && liftedValueType)) {
                        toProperty.SetValue(to, fromValue);
                    }
                }
            }
        }
    }

}

 

谢谢浏览!