创建我自己的映射器

Question

这是我的情况。我有 2 个 classes，TmdbTvShow 和 TvShow。

TmdbTvShow class 充满了我从外部来源获得的数据。现在我想创建某种映射器将其映射到我自己的 class、TvShow.

Class 电视剧：

 [MovieMap("TmdbTvShow")]
public class TvShow
{
    public int ID { get; set; }
    [MovieMapProperty("ID")]
    public int TmdbID { get; set; }

    [MovieMapProperty("Name")]
    public string Name { get; set; }

    [MovieMapProperty("OriginalName")]
    public string OriginalName { get; set; }

    [MovieMapProperty("Overview")]
    public string Summary { get; set; }

    [MovieMapProperty("FirstAirDate")]
    public DateTime FirstAirDate { get; set; }

    [MovieMapProperty("LastAirDate")]
    public DateTime LastAirDate { get; set; }

    [MovieMapProperty("Genres")]
    public IEnumerable<Genre> Genres { get; set; }

    [MovieMapProperty("InProduction")]
    public bool Running { get; set; }

}

映射器class:

public class MovieMapper
{
    public MovieMapper()
    {          
    }

    public T Map<T>(object input) where T : new()
    {
        T obj = new T();

        MovieMapAttribute[] classAttributes = (MovieMapAttribute[])obj.GetType().GetCustomAttributes(typeof(MovieMapAttribute), false);

        if (classAttributes != null && classAttributes[0].ClassName.Equals(input.GetType().Name))
        {
            Dictionary<string, MovieMapPropertyAttribute> propAtts = new Dictionary<string, MovieMapPropertyAttribute>();

            foreach (PropertyInfo prop in obj.GetType().GetProperties())
            {
                MovieMapPropertyAttribute[] mma = (MovieMapPropertyAttribute[])prop.GetCustomAttributes(typeof(MovieMapPropertyAttribute), false);

                // Attribute found
                if (mma.Length > 0)
                {
                    // Get attribute
                    MovieMapPropertyAttribute mmp = mma[0];

                    // Get value
                    var value = input.GetType().GetProperty(mmp.PropertyName).GetValue(input, null);

                    // Is property a dateTime
                    if (typeof(DateTime).IsAssignableFrom(prop.PropertyType))
                    {
                        // Set value to object
                        obj.GetType().GetProperty(prop.Name).SetValue(obj, Convert.ToDateTime(value), null);
                    }
                    else if (typeof(IEnumerable).IsAssignableFrom(prop.PropertyType) && prop.PropertyType != typeof(string))
                    {

                    }
                    else if (typeof(Boolean).IsAssignableFrom(prop.PropertyType))
                    {
                        // Set value to object
                        obj.GetType().GetProperty(prop.Name).SetValue(obj, Convert.ToBoolean(value), null);
                    }
                    else
                    {
                        // Set value to object
                        obj.GetType().GetProperty(prop.Name).SetValue(obj, value, null);
                    }
                }                        
            }

        }
        else
            throw new Exception("Wrong object");

        return obj;
    }       
}

所以 atm 我开始工作了，int、string、booleans 和 DateTime 之类的东西正在映射到我的对象。

但是如您所见，我的 TvShow class 中有一个 IEnumerable。这是此 TvShow 的流派合集。

我对如何使 2 个 IEnumerables 彼此映射有点困惑。如果我像字符串那样做，我会收到此错误：

a object of type System.Collections.Generic.List can not be converted to the     type System.Collections.Generic.IEnumerable

也许有人可以告诉我如何处理这个问题的正确方向？

干杯

Answer 1

您可以创建一个 IEnumerable 列表，向其中添加项目，然后将其分配给属性。

如果您需要将对象从 TmdbGenre 转换为 Genre，您可以递归调用 Map，但您可能需要一个接受类型的 Map 版本范围。

public object Map(Type type, object input);

var result = value.Select(x => Map(prop.GetType().GetGenericArguments()[0], x));
prop.SetValue(obj, result);

Answer 2

好的，经过大量尝试我已经弄明白了。

这是我的解决方案：

 public T Map<T>(object input) where T : new()
    {
        T obj = new T();

        MovieMapAttribute[] classAttributes = (MovieMapAttribute[])obj.GetType().GetCustomAttributes(typeof(MovieMapAttribute), false);

        if (classAttributes != null && classAttributes[0].ClassName.Equals(input.GetType().Name))
        {
            Dictionary<string, MovieMapPropertyAttribute> propAtts = new Dictionary<string, MovieMapPropertyAttribute>();

            foreach (PropertyInfo prop in obj.GetType().GetProperties())
            {
                MovieMapPropertyAttribute[] mma = (MovieMapPropertyAttribute[])prop.GetCustomAttributes(typeof(MovieMapPropertyAttribute), false);

                // Attribute found
                if (mma.Length > 0)
                {
                    // Get attribute
                    MovieMapPropertyAttribute mmp = mma[0];

                    if (input.GetType().GetProperty(mmp.PropertyName) != null)
                    {
                        // Get value
                        var value = input.GetType().GetProperty(mmp.PropertyName).GetValue(input, null);

                        // Is property a dateTime
                        if (typeof(DateTime).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            obj.GetType().GetProperty(prop.Name).SetValue(obj, Convert.ToDateTime(value), null);
                        }
                        else if (typeof(IEnumerable).IsAssignableFrom(prop.PropertyType) && prop.PropertyType != typeof(string) && prop.PropertyType != typeof(string[]))
                        {
                            Type type = prop.PropertyType.GetGenericArguments()[0];
                            var list = (IEnumerable)value;
                            dynamic values = Activator.CreateInstance(typeof(List<>).MakeGenericType(type));

                            foreach (object ob in list)
                            {

                                object tempObj = Activator.CreateInstance(type);

                                tempObj = Map(ob, tempObj);

                                values.Add((dynamic)tempObj);
                            }

                            obj.GetType().GetProperty(prop.Name).SetValue(obj, values, null);
                        }
                        else if (typeof(Boolean).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            obj.GetType().GetProperty(prop.Name).SetValue(obj, Convert.ToBoolean(value), null);
                        }
                        else if (typeof(int).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            obj.GetType().GetProperty(prop.Name).SetValue(obj, Convert.ToInt32(value), null);
                        }
                        else if (typeof(float).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            obj.GetType().GetProperty(prop.Name).SetValue(obj, float.Parse(value.ToString(), System.Globalization.CultureInfo.InvariantCulture.NumberFormat), null);
                        }
                        else
                        {
                            // Set value to object
                            obj.GetType().GetProperty(prop.Name).SetValue(obj, value, null);
                        }
                    }
                }        
            }

        }
        else
            throw new Exception("Wrong object");

        return obj;
    }       

    private object Map(object input, object output)
    {
        MovieMapAttribute[] classAttributes = (MovieMapAttribute[])output.GetType().GetCustomAttributes(typeof(MovieMapAttribute), false);

        if (classAttributes != null && classAttributes[0].ClassName.Equals(input.GetType().Name))
        {
            foreach (PropertyInfo prop in output.GetType().GetProperties())
            {
                MovieMapPropertyAttribute[] mma = (MovieMapPropertyAttribute[])prop.GetCustomAttributes(typeof(MovieMapPropertyAttribute), false);

                // Attribute found
                if (mma.Length > 0)
                {
                    // Get attribute
                    MovieMapPropertyAttribute mmp = mma[0];

                    if (input.GetType().GetProperty(mmp.PropertyName) != null)
                    {

                        var value = input.GetType().GetProperty(mmp.PropertyName).GetValue(input, null);

                        // Is property a dateTime
                        if (typeof(DateTime).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            output.GetType().GetProperty(prop.Name).SetValue(output, Convert.ToDateTime(value), null);
                        }
                        else if (typeof(IEnumerable).IsAssignableFrom(prop.PropertyType) && prop.PropertyType != typeof(string) && prop.PropertyType != typeof(string[]))
                        {
                            Type type = prop.PropertyType.GetGenericArguments()[0];
                            var list = (IEnumerable)value;
                            dynamic values = Activator.CreateInstance(typeof(List<>).MakeGenericType(type));

                            foreach (object ob in list)
                            {

                                object tempObj = Activator.CreateInstance(type);

                                tempObj = Map(ob, tempObj);

                                values.Add((dynamic)tempObj);
                            }

                            output.GetType().GetProperty(prop.Name).SetValue(output, values, null);
                        }
                        else if (typeof(Boolean).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            output.GetType().GetProperty(prop.Name).SetValue(output, Convert.ToBoolean(value), null);
                        }
                        else if (typeof(int).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            output.GetType().GetProperty(prop.Name).SetValue(output, Convert.ToInt32(value), null);
                        }
                        else if (typeof(float).IsAssignableFrom(prop.PropertyType))
                        {
                            // Set value to object
                            output.GetType().GetProperty(prop.Name).SetValue(output, float.Parse(value.ToString(), System.Globalization.CultureInfo.InvariantCulture.NumberFormat), null);
                        }
                        else
                        {
                            // Set value to object
                            output.GetType().GetProperty(prop.Name).SetValue(output, value, null);
                        }
                    }                        
                }
            }
        }
        else
            throw new Exception("Wrong object");

        return output;
    }

它工作正常，它将 ienumerables 映射到 ienumerables 等中。

感谢 Ned 为我指明了正确的方向，我会把你作为一个好的答案！

创建我自己的映射器

Creating my own mapper

c#

generics

mapping

ienumerable