格式化json字符串并将其传递给带有参数的主体会产生错误

Question

I am trying to create a post request using RestSharp.

I have the following string

"{ \"name\": \"string\", \"type\": \"string\", \"parentId\": \"string\", \"Location\": [ \"string\" ]}"

I need to pass that into the json body to send a POST request I am trying the following.

public IRestResponse PostNewLocation(string Name, string Type, Nullable<Guid> ParentId, string Locatations)
{
  string NewLocation = string.Format("{ \"name\": \"{0}\", \"type\": \"{1}\", \"parentId\": \"{2}\", \"Location\": [ \"{3}\" ]}", Name, Type, ParentId, Location);
  var request = new RestRequest(Method.POST);
  request.Resource = string.Format("/Sample/Url");
  request.AddParameter("application/json", NewLocation, ParameterType.RequestBody);
  IRestResponse response = Client.Execute(request);
}

And the error

Message: System.FormatException : Input string was not in a correct format.

How can I format the above string to pass it into the json body?

My Test fails at this line

string NewLocation = string.Format("{ \"name\": \"{0}\", \"type\": \"{1}\", \"parentId\": \"{2}\", \"Location\": [ \"{3}\" ]}", Name, Type, ParentId, Location);

Answer 1

You've got open braces in your format string, but without them being format items. You could use double braces instead:

// With more properties of course
string newLocation = string.Format("{{ \"name\": \"{0}\" }}", Name);

... but I'd strongly recommend that you don't. Instead, produce JSON using a JSON library, eg Json.NET. It's really simple, either using classes or anonymous types. For example:

object tmp = new
{
    name = Name,
    type = Type,
    parentId = ParentId,
    Location = Location
};
string json = JsonConvert.SerializeObject(tmp);

That way:

• You don't need to worry about whether your name, type etc contain characters that need to be escaped
• You don't need to worry about format strings
• Your code is much easier to read

Answer 2

The problem is the curly braces used at the start and end of your format string (since they have a special meaning). Escape them by adding an additional brace like so:

string NewLocation = string.Format("{{ \"name\": \"{0}\", \"type\": \"{1}\", \"parentId\": \"{2}\", \"Location\": [ \"{3}\" ]}}", Name, Type, ParentId, Location);