Json: how to properly strip the escape characters with json.net

Question

I have json response in the below format.

"[{\\\"JobID\\\":\\\"1\\\",\\\"BillGenerationDate\\\":\\\"4/29/2013 2:53:34 PM\\\",\\\"BillID\\\":\\\"115743\\\",\\\"BillNo\\\":\\\"115743\\\",\\\"CustomerID\\\":\\\"4041705\\\",\\\"PayStatus\\\":\\\"0\\\",\\\"PaymentRequiredStatus\\\":\\\"True\\\",\\\"ProductName\\\":\\\"Epic FBO test\\\",\\\"Description\\\":\\\"Epic Automation 2\\\\r\\\\n\\\",\\\"ProductType\\\":\\\"eBill \\\",\\\"DueType\\\":\\\"-1\\\",\\\"DueDate\\\":\\\"2013-03-15\\\",\\\"Amount\\\":\\\"63.70\\\",\\\"Cost\\\":\\\"\\\"},
{\\\"JobID\\\":\\\"9\\\",\\\"BillGenerationDate\\\":\\\"5/2/2013 10:21:39 AM\\\",\\\"BillID\\\":\\\"115743\\\",\\\"BillNo\\\":\\\"115743\\\",\\\"CustomerID\\\":\\\"4041705\\\",\\\"PayStatus\\\":\\\"0\\\",\\\"PaymentRequiredStatus\\\":\\\"True\\\",\\\"ProductName\\\":\\\"FBO Test Product\\\",\\\"Description\\\":\\\"FBO Product Test\\\",\\\"ProductType\\\":\\\"eBill \\\",\\\"DueType\\\":\\\"-1\\\",\\\"DueDate\\\":\\\"2013-05-01\\\",\\\"Amount\\\":\\\"150.70\\\",\\\"Cost\\\":\\\"\\\"}]

I believe json.net handles the escape characters and I used the below code to deserialize it to a dictionary collection.

var billList = JsonConvert.DeserializeObject<List<Dictionary<string, string>>>(contentCorrected);

But this json parsing throws exception "Invalid property identifier character: . Path '[0]', line 1, position 2." Could we solve this by manipulating the json response string?

Answer 1

THE SHORT ANSWER: first you need to deserialize the escaped string, but not to the target CLR type, but deserialize to another string (repeat if necessary); then, it is deserialized to the target type:

// Initial example json string:  "\"{\\\"Property1\\\":1988,\\\"Property2\\\":\\\"Some data :D\\\"}\""


// First, deserialize to another string (unescaped string).
string unescapedJsonString = JsonConvert.DeserializeObject<string>(escapedJsonString);
Debug.WriteLine(unescapedJsonString);
// Prints:
// "{\"Property1\":1988,\"Property2\":\"Some data :D\"}"


// Second, deserialize to another string, again (in this case is necessary)
var finalUnescapedJsonString = JsonConvert.DeserializeObject<string>(unescapedJsonString);
Debug.WriteLine(finalUnescapedJsonString);
// This time prints a final, unescaped, json string:
// {"Property1":1988,"Property2":"Some data :D"}


// Finally, perform final deserialization to the target type, using the last unescaped string.
MyClass targetObject = JsonConvert.DeserializeObject<MyClass>(finalUnescapedJsonString);

LONG ANSWER (but interesting) Using string.Replace(... could generate an invalid string, because it could damage certain special characters that needed the backslash to be deserialized correctly .

This type of escaped strings are usually generated when a string that was already a json string, its serialized again (or even more times). This causes something like "various levels of serialization" (it really is a serialization of a string with reserved characters), and the result is backshash characters (or groups of one, two or more backslash followed: \, \, \\\) scattered all over the string. So, to remove them correctly is not enough to replace them by empty.

THE RIGHT WAY: A better way to get a unescaped string would be to do a first deserialization to string type (Repeat this several times if necessary), And then do a final deserialization to target CLR type:

// -- SERIALIZATION --

// Initial object
MyClass originObj = new MyClass { Property1 = 1988, Property2 = "Some data :D" };

// "First level" Of serialization.
string jsonString = JsonConvert.SerializeObject(originObj);
Debug.WriteLine(jsonString);
// Prints: 
// {"Property1":1988,"Property2":"Some data :D"}


// "Second level" of serialization.
string escapedJsonString = JsonConvert.SerializeObject(jsonString);
Debug.WriteLine(escapedJsonString);            
// "{\"Property1\":1988,\"Property2\":\"Some data :D\"}"
// Note the initial and final " character and de backslash characters

// ...
// at this point you could do more serializations ("More levels"), Obtaining as a result more and more backslash followed,
// something like this:
// "\"{\\\"Property1\\\":1988,\\\"Property2\\\":\\\"Some data :D\\\"}\""
// Note that is... very very crazy :D
// ...

// -- DESERIALIZATION --

// First deserialize to another string (unescaped string).
string unescapedJsonString = JsonConvert.DeserializeObject<string>(escapedJsonString);
Debug.WriteLine(unescapedJsonString);
// Prints:
// {"Property1":1988,"Property2":"Some data :D"}

// ...
// at this point you could repeat more deserializations to string, if necessary. For example if you have many backslash \\\
// ...

// Finally, perform final deserialization to the target type, using the last unescaped string.
MyClass targetObject = JsonConvert.DeserializeObject<MyClass>(unescapedJsonString);