如何使用 JSON.NET 确保字符串是有效的 JSON

Simplest way would be to Parse the string using JToken.Parse, and also to check if the string starts with { or [ and ends with } or ] respectively (added from this answer):

private static bool IsValidJson(string strInput)
{
    if (string.IsNullOrWhiteSpace(strInput)) { return false;}
    strInput = strInput.Trim();
    if ((strInput.StartsWith("{") && strInput.EndsWith("}")) || //For object
        (strInput.StartsWith("[") && strInput.EndsWith("]"))) //For array
    {
        try
        {
            var obj = JToken.Parse(strInput);
            return true;
        }
        catch (JsonReaderException jex)
        {
            //Exception in parsing json
            Console.WriteLine(jex.Message);
            return false;
        }
        catch (Exception ex) //some other exception
        {
            Console.WriteLine(ex.ToString());
            return false;
        }
    }
    else
    {
        return false;
    }
}

为 { 或 [ 等添加检查的原因是基于 JToken.Parse 将解析值的事实例如 1234" 或 'a string'" 作为有效标记.另一种选择可能是在解析中同时使用 JObject.Parse 和 JArray.Parse 并查看其中是否有人成功，但我相信检查 {} 和 [] 应该更容易. (感谢@RhinoDevel 指出)

The reason to add checks for { or [ etc was based on the fact that JToken.Parse would parse the values such as "1234" or "'a string'" as a valid token. The other option could be to use both JObject.Parse and JArray.Parse in parsing and see if anyone of them succeeds, but I believe checking for {} and [] should be easier. (Thanks @RhinoDevel for pointing it out)

没有 JSON.Net

您可以使用 .Net framework 4.5 System.Json 命名空间，如:

You can utilize .Net framework 4.5 System.Json namespace ,like:

string jsonString = "someString";
try
{
    var tmpObj = JsonValue.Parse(jsonString);
}
catch (FormatException fex)
{
    //Invalid json format
    Console.WriteLine(fex);
}
catch (Exception ex) //some other exception
{
    Console.WriteLine(ex.ToString());
}

(但是，您必须使用以下命令通过 Nuget 包管理器安装 System.Json:PM>;Install-Package System.Json -Version 4.0.20126.16343在包管理器控制台上)(取自这里)

(But, you have to install System.Json through Nuget package manager using command: PM> Install-Package System.Json -Version 4.0.20126.16343 on Package Manager Console) (taken from here)

非编码方式:

通常，当有一个小的 json 字符串并且您试图在 json 字符串中查找错误时，我个人更喜欢使用可用的在线工具.我通常做的是:

Usually, when there is a small json string and you are trying to find a mistake in the json string, then I personally prefer to use available on-line tools. What I usually do is:

• 将 JSON 字符串粘贴到 JSONLint The JSON Validator 并查看是否它是一个有效的 JSON.
• 稍后将正确的 JSON 复制到 http://json2csharp.com/ 和为它生成一个模板类，然后反序列化它使用 JSON.Net.

• Paste JSON string in JSONLint The JSON Validator and see if its a valid JSON.
• Later copy the correct JSON to http://json2csharp.com/ and generate a template class for it and then de-serialize it using JSON.Net.

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