Store Hardcoded JSON string to variable

Simple Approach is to copy the JSON to a .json file and read that file in the code

string jsonData = string.Empty;
jsonData = File.ReadAllText(@"\UISettings.json");

First things first, I'll throw this out there: It's for this reason in JSON blobs that I like to use single quotes.

But, much depends on how you're going to declare your string variable.

string jsonBlob = @"{ 'Foo': 'Bar' }";
string otherBlob = @"{ ""Foo"": ""Bar"" }";

...This is an ASCII-encoded string, and it should play nicely with single quotes. You can use the double-double-quote escape sequence to escape the doubles, but a single quote setup is cleaner. Note that \" won't work in this case.

string jsonBlob = "{ 'Foo': 'Bar' }";
string otherBlob = "{ \"Foo\": \"Bar\" }";

...This declaration uses C#'s default string encoding, Unicode. Note that you have to use the slash escape sequence with double quotes - double-doubles will not work - but that singles are unaffected.

From this, you can see that single-quote JSON literals are unaffected by the C# string encoding that is being used. This is why I say that single-quotes are better to use in a hardcoded JSON blob than doubles - they're less work, and more readable.

You have to escape the "'s if you use the @ symbol it doesn't allow the \ to be used as an escape after the first ". So the two options are:

don't use the @ and use \ to escape the "

string someJson = "{\"ErrorMessage\": \"\",\"ErrorDetails\": {\"ErrorID\": 111,\"Description\":{\"Short\": 0,\"Verbose\": 20},\"ErrorDate\": \"\"}}";

or use double quotes

string someJson =@"{""ErrorMessage"": """",""ErrorDetails"": {""ErrorID"": 111,""Description"": {""Short"": 0,""Verbose"": 20},""ErrorDate"": """"}}";