C# Asp.Net Web API 中带有字典参数的方法

Method with Dictionary Parameter in Asp.Net Web API

提问by kkocabiyik

I need to make a GET request to a method that contains Dictionary as a parameter. I browse through but could not find any kinds of information about how I could send Dictionary so my request hit to my method. Method signature is as like as below

我需要向包含 Dictionary 作为参数的方法发出 GET 请求。我浏览但找不到任何关于如何发送字典的信息，所以我的请求命中了我的方法。方法签名如下

public void AddItems(Dictionary<string,object> Items)

Best Regards,

此致，

Kemal

凯末尔

采纳答案by Kirill Bestemyanov

Did you read ASP.NET Wire Format for Model Binding to Arrays, Lists, Collections, Dictionaries

你读过ASP.NET Wire Format for Model Binding to Arrays, Lists, Collections, Dictionaries

回答by Kunal

You Can Use Dictionary As A Parameter In This Way:

您可以通过以下方式使用字典作为参数：

protected object DictionaryFunction()
{
    Dictionary<int,YourObjectName> YourDictionaryObjectName=new Dictionary<int,YourObjectName>();
    ...
    ...

    return YourDictionaryObjectName;
}

protected MyFunction()
{
    Dictionary<int,YourObjectName> MyDictionary=(Dictionary<int,YourObjectName>)DictionaryFunction();
}

回答by Amir Yonatan

I wrote a ModelBinder that does exactly what you wanted:

我写了一个 ModelBinder，它完全符合你的要求：

public class DictionaryModelBinder : DefaultModelBinder
{
    private const string _dateTimeFormat = "dd/MM/yyyy HH:mm:ss";

    private enum StateMachine
    {
        NewSection,
        Key,
        Delimiter,
        Value,
        ValueArray
    }

    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var stream = controllerContext.HttpContext.Request.InputStream;
        string text;

        stream.Position = 0;
        using (var reader = new StreamReader(stream))
        {
            text = reader.ReadToEnd();
        }

        int index = 0;
        return Build(text, ref index);
    }

    private static Dictionary<string, object> Build(string text, ref int index)
    {
        var state = StateMachine.NewSection;
        var dictionary = new Dictionary<string, object>();
        var key = string.Empty;
        object value = string.Empty;

        for (; index < text.Length; ++index)
        {
            if (state == StateMachine.NewSection && text[index] == '{')
            {
                dictionary = new Dictionary<string, object>();
                state = StateMachine.NewSection;
            }
            else if (state == StateMachine.NewSection && text[index] == '"')
            {
                key = string.Empty;
                state = StateMachine.Key;
            }
            else if (state == StateMachine.Key && text[index] != '"')
            {
                key += text[index];
            }
            else if (state == StateMachine.Key && text[index] == '"')
            {
                state = StateMachine.Delimiter;
            }
            else if (state == StateMachine.Delimiter && text[index] == ':')
            {
                state = StateMachine.Value;
                value = string.Empty;
            }
            else if (state == StateMachine.Value && text[index] == '[')
            {
                state = StateMachine.ValueArray;
                value = value.ToString() + text[index];
            }
            else if (state == StateMachine.ValueArray && text[index] == ']')
            {
                state = StateMachine.Value;
                value = value.ToString() + text[index];
            }
            else if (state == StateMachine.Value && text[index] == '{')
            {
                value = Build(text, ref index);
            }
            else if (state == StateMachine.Value && text[index] == ',')
            {
                dictionary.Add(key, ConvertValue(value));
                state = StateMachine.NewSection;
            }
            else if (state == StateMachine.Value && text[index] == '}')
            {
                dictionary.Add(key, ConvertValue(value));
                return dictionary;
            }
            else if (state == StateMachine.Value || state == StateMachine.ValueArray)
            {
                value = value.ToString() + text[index];
            }
        }

        return dictionary;
    }

    private static object ConvertValue(object value)
    {
        string valueStr;
        if (value is Dictionary<string, object> || value == null || (valueStr = value.ToString()).Length == 0)
        {
            return value;
        }

        bool boolValue;
        if (bool.TryParse(valueStr, out boolValue))
        {
            return boolValue;
        }

        int intValue;
        if (int.TryParse(valueStr, out intValue))
        {
            return intValue;
        }

        double doubleValue;
        if (double.TryParse(valueStr, out doubleValue))
        {
            return doubleValue;
        }

        valueStr = valueStr.Trim('"');

        DateTime datetimeValue;
        if (DateTime.TryParseExact(valueStr, _dateTimeFormat, CultureInfo.InvariantCulture, DateTimeStyles.None, out datetimeValue))
        {
            return datetimeValue;
        }

        if (valueStr.First() == '[' && valueStr.Last() == ']')
        {
            valueStr = valueStr.Trim('[', ']');
            if (valueStr.Length > 0)
            {
                if (valueStr[0] == '"')
                {
                    return valueStr
                        .Split(new[] { '"' }, StringSplitOptions.RemoveEmptyEntries)
                        .Where(x => x != ",")
                        .ToArray();
                }
                else
                {
                    return valueStr
                        .Split(',')
                        .Select(x => ConvertValue(x.Trim()))
                        .ToArray();
                }
            }
        }

        return valueStr;
    }
}

More explanations and full post you can see in my blog:

您可以在我的博客中看到更多解释和完整帖子：

Json To Dictionary generic model binder

Json To Dictionary 通用模型绑定器

回答by Cubelaster

If you have problems receiving Dictionary in your webApi controller, relatively painless solution is to switch the parameter to List<"ObjectRepresentingDict"> insetead. It will map automatically.

如果您在 webApi 控制器中接收字典时遇到问题，相对轻松的解决方案是将参数切换到 List<"ObjectRepresentingDict"> insetead。它会自动映射。