Why is my JSON.NET Serialization Producing Double-Encoded JSON Strings?

JSON.NET serialization problem

Problem Overview

When using JSON.NET's JsonConvert.SerializeObject method, the object is double-serialized, resulting in an incorrect JSON response. The response is wrapped in quotes and embedded quotes are escaped, resulting in invalid JSON.

Roots

This issue usually occurs when returning a string from a WebAPI controller that has been serialized using JSON.NET. The controller then additionally serializes the string into a JavaScript string literal, resulting in double serialization.

Solution

To solve this problem, directly return the object itself instead of the string. By doing this, the API controller will handle the serialization based on the request parameters, allowing JSON.NET to serialize the object correctly. This eliminates double serialization and ensures that the generated JSON response is valid.

Example

<code class="language-csharp">// 原代码：双重序列化
public string GetFoobars() {
    var foobars = ...;
    return JsonConvert.SerializeObject(foobars);
}

// 更新后的代码：直接返回对象
public IEnumerable<Foobar> GetFoobars() {
    var foobars = ...;
    return foobars;
}</code>

By updating the return type to the actual type of the object being serialized, the controller will serialize the result appropriately, thus resolving the double serialization issue.

Additional information

For more information about serialization in WebAPI, please refer to the following resources:

• JSON and XML serialization in ASP.NET Web API

The above is the detailed content of Why is my JSON.NET Serialization Producing Double-Encoded JSON Strings?. For more information, please follow other related articles on the PHP Chinese website!