What C#/Linq code copies all matching property name values between two objects without knowing their type?

I have a well known POCO class of Customer to return from my method. However, I only populate properties specified by an ever changing Expression 开发者_运维知识库p => new {p.id, p.name} for example, as a parameter to the method.

Somehow I need to copy all matching fields between these two objects.

var returnObject = IList<Customer>();
var partialFieldObject = DC.Customers.Select( expParameter); // wont know the fields

foreach( var partialRecord in partialFieldObject)
{    foreach (var property in partialRecord // Pseudo code)
     {
         returnObject[property] = property.value; // More Pseudo code
     }
}
End result is a strongly typed Customer POCO returned that only has the selected fields populated with values.

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Some simple reflection does the trick, assuming the properties on partialFieldObject line up exactly (case-sensitive) with properties on Customer...

void SetProperties(object source, object target)
{
    var customerType = target.GetType();
    foreach (var prop in source.GetType().GetProperties())
    {
        var propGetter = prop.GetGetMethod();
        var propSetter = customerType.GetProperty(prop.Name).GetSetMethod();
        var valueToSet = propGetter.Invoke(source, null);
        propSetter.Invoke(target, new[] { valueToSet });
    }
}

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You can use AutoMapper - it's built to do this stuff I think

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Adapting dahlbyk's accepted answer, I've ended up using the following in a constructor that accepted a base-type and needed to mirror the contents:

var thisType = this.GetType();
foreach (var prop in baseObj.GetType().GetProperties()
    .Where(p => thisType.GetProperty(p.Name) != null))
{
    var propGetter = prop.GetGetMethod();
    var propSetter = thisType.GetProperty(prop.Name).GetSetMethod();
    if (propSetter != null)
        propSetter.Invoke(this, new[] { propGetter.Invoke(baseObj, null) });
}

Basically, step through each property in the baseObj type where this type has a property with a matching name, and locate the get method on the baseObj type as well as the set method for the matching named property on this type and if there is a set method available on this, invoke it using the method returned from the invocation of the get method on the baseObj type.

Works well for public & private properties of any (matching) type on both types.

Note: You'll need a reference to System.Linq for the .Where() func in the loop

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Not that different, just the most compact and cleanest form I found:

void CopyProperties(object src, object dest) {
  foreach (var source in src.GetType().GetProperties().Where(p => p.CanRead)) {
    var prop = dest.GetType().GetProperty(source.Name);
    if (prop?.CanWrite == true)
      prop.SetValue(dest, source.GetValue(src, null), null);
  }
}

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    public static void CopyPropertiesTo<T, TU>(this T source, TU dest)
    {

        var sourceProps = typeof (T).GetProperties().Where(x => x.CanRead).ToList();
        var destProps = typeof(TU).GetProperties()
                .Where(x => x.CanWrite)
                .ToList();

        foreach (var sourceProp in sourceProps)
        {
            if (destProps.Any(x => x.Name == sourceProp.Name))
            {
                var p = destProps.First(x => x.Name == sourceProp.Name);
                p.SetValue(dest, sourceProp.GetValue(source, null), null);
            }

        }

    }

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void Copy(object copyToObject, object copyFromObject)
{
    BindingFlags flags = BindingFlags.Public | BindingFlags.Instance;

    FieldInfo[] fields = copyFromObject.GetType().GetFields(flags);
    for (int i = 0; i < fields.Length; ++i)
    {
        FieldInfo fromField = copyFromObject.GetType().GetField(fields[i].Name, flags);
        FieldInfo toField = copyToObject.GetType().GetField(fields[i].Name, flags);
        if(fromField != null)
        {
            toField.SetValue(copyToObject, fromField.GetValue(copyFromObject));
        }
    }
}