如何将条件与类匹配（实现接口）并调用其应用方法

Question

In my console application, i have an interface named IFileConverter given below:

public interface IFileConverter
{
    string InputFileFormat { get; }
    string OutputFileFormat { get; }
    object Convert(object input);
}

And some of class templates that implement this interface are: Png2JpgConverter class code is;

/// <summary>
/// Image of class of converter Png file to Jpg file.
/// </summary>
public class Png2JpgConverter : IFileConverter
{
    public string InputFileFormat => "png";

    public string OutputFileFormat => "jpg";

    public object Convert(object input) => "this is a jpg file.";   // TODO ...
}

and another class for example: Jpg2BmpConverter class code is;

/// <summary>
/// Image of class of converter Jpg file to Bmp file.
/// </summary>
public class Jpg2BmpConverter : IFileConverter
{
    public string InputFileFormat => "jpg";

    public string OutputFileFormat => "bmp";

    public object Convert(object input) => "this is a bmp file.";   // TODO ..
}

And i have InputFileFormat which is: string inputFileFormat = "png";

OutputFileFormat which is: string outputFileFormat = "jpg";

And object is object input = "this is a png file.";

My question is; i want to call Convert() method of appropriate class for imaginary conversion process. But i neeed to do that in valid operation. Is there any way to do like that given below?

static void Main(string[] args)
    {
        string inputFileFormat = "png";
        string outputFileFormat = "jpg";
        object input = "this is a png file."; // for example


        //here i want to call method of Convert() like this:
        if(var selectedConverter is IFileConverter converter)
        {
            object output = selectedConverter.Convert(input);
        }
        // but i don't know how to do it and how to match inputFileFormat and outputFileFormat
        // in appropriate class that impelents IFileConverter interface...
    }

Any help would be nice..

Answer 1

if I have understood what you meant, I think the concept of "Polymorphism" will help in such a situation

var converters = new List<IFileConverter> {new Jpg2BmpConverter(), new Png2JpgConverter()};

var outputList = new List<object>();

foreach (var fileConverter in converters)
{
    outputList.Add(fileConverter.Convert(input));
}

now you have a list of the outputs, you can do what you want with it.

Answer 2

An image in memory is only a matrix Width X Height X Channels. PNG and JPG are compression methods used for save these matrixes on disk.

Want you convert disk files?

bmp -> png example

string filepath = "PathToBMPImage.bmp";
string savePath = "PathToPngOutout.png";
//Load the image, don't use new System.Drawing.Bitmap(string path) because it'll convert the image in 32BPP
using(var bmp = (System.Drawing.Bitmap)System.Drawing.Image.FromFile(filepath))
 //Now inside bmp there is a matrix WxHxC
 bmp.Save(savePath, System.Drawing.Imaging.ImageFormat.Png);

All GDI encoder and decoders are here . You can add parameters to encoders parameters like jpg compression.