C# Merge Dictionaries
While working on my Game client conversion, which is why I have not posted many articles for a while, I found a need to merge two dictionaries into a single dictionary. Its not a real complicated process, but I all the examples I found would alway use the item from the first dictionary or would throw exceptions on a duplicate. To get around these two scenarios I created the **MergeLayoutControlOptions** method below, it takes in a list of Dictionary typed objects and merges them with the last grouped value taking priority in the new Dictionary.
To give a real world scenario I am using a class that extends the framework Dictionary. I like this pattern since it allows me to create explicit wrappers around a Dictionary, but still get the functionality of the framework provided Dictionary. Using this pattern also allows me to add functionality to the way a Dictionary works without having to create extensions methods, that make it hard to test. Another added benefit is that I also get a typed object for my options instead of a generic dictionary that I have to know I have extension methods to work with it.
Example of Generated Source
You can checkout this fiddle Merge Dictionaries to play around with the code that is provided below.
Example output:
Key: key1 | Value: value1
Key: key2 | Value: value2-from2
Key: key3 | Value: value3
Key: key4 | Value: value4-from2
Key: key5 | Value: value5
using System;
using System.Linq;
using System.Collections.Generic;
public class Program
{
public static void Main()
{
var options1 = new GuiControlOptionsModel(
new Dictionary<string, object>
{
{"key1", "value1"},
{"key2", "value2"},
{"key3", "value3"},
{"key4", "value4"},
{"key5", "value5"},
}
);
var options2 = new GuiControlOptionsModel(
new Dictionary<string, object>
{
{"key2", "value2-from2"},
{"key4", "value4-from2"},
}
);
var mergedOptions = MergeLayoutControlOptions(
options1,
options2
);
foreach (var option in mergedOptions)
{
System.Console.WriteLine(
$"Key: {option.Key} | Value: {option.Value}"
);
}
}
/// <summary>
/// Will merge the provided options into a single options.
/// Will use the last option value as priority in new Option Model.
/// </summary>
/// <param name="options">Options to merge values from.</param>
/// <returns>A consolidated Options Model of all passed in Option Key/Value</returns>
private static GuiControlOptionsModel MergeLayoutControlOptions(
params IGuiControlOptions[] options
)
{
return new GuiControlOptionsModel(
options.SelectMany(x => x)
.GroupBy(d => d.Key)
.ToDictionary(x => x.Key, y => y.Last().Value)
);
}
public interface IGuiControlOptions
: IDictionary<string, object>
{
}
public class GuiControlOptionsModel
: Dictionary<string, object>,
IGuiControlOptions
{
public GuiControlOptionsModel(
IDictionary<string, object> dictionary
) : base(dictionary ?? new Dictionary<string, object>())
{
}
}
}
