How to add variables inside a StringContent("")

Question

Good day,

I'm really new to programming and trying to play around APIs.

I saw this example from the API documentation

using (var content = new StringContent("{  \"orderNumber\": \"TEST-ORDER-API-DOCS\",  \"orderKey\": \"0f6bec18-3e89-4881-83aa-f392d84f4c74\",  \"orderDate\": \"2015-06-29T08:46:27.0000000\",  \"paymentDate\": \"2015-06-29T08:46:27.0000000\",  \"shipByDate\": \"2015-07-05T00:00:00.0000000\",  \"orderStatus\": \"awaiting_shipment\",  \"customerId\": 37701499,  \"customerUsername\": \"[email protected]\",  \"customerEmail\": \"[email protected]\",  \"billTo\": {    \"name\": \"The President\",    \"company\": null,    \"street1\": null,    \"street2\": null,    \"street3\": null,    \"city\": null,    \"state\": null,    \"postalCode\": null,    \"country\": null,    \"phone\": null,    \"residential\": null  },  \"shipTo\": {    \"name\": \"The President\",    \"company\": \"US Govt\",    \"street1\": \"1600 Pennsylvania Ave\",    \"street2\": \"Oval Office\",    \"street3\": null,    \"city\": \"Washington\",    \"state\": \"DC\",    \"postalCode\": \"20500\",    \"country\": \"US\",    \"phone\": \"555-555-5555\",    \"residential\": true  },  \"items\": [    {      \"lineItemKey\": \"vd08-MSLbtx\",      \"sku\": \"ABC123\",      \"name\": \"Test item #1\",      \"imageUrl\": null,      \"weight\": {        \"value\": 24,        \"units\": \"ounces\"      },      \"quantity\": 2,      \"unitPrice\": 99.99,      \"taxAmount\": 2.5,      \"shippingAmount\": 5,      \"warehouseLocation\": \"Aisle 1, Bin 7\",      \"options\": [        {          \"name\": \"Size\",          \"value\": \"Large\"        }      ],      \"productId\": 123456,      \"fulfillmentSku\": null,      \"adjustment\": false,      \"upc\": \"32-65-98\"    },    {      \"lineItemKey\": null,      \"sku\": \"DISCOUNT CODE\",      \"name\": \"10% OFF\",      \"imageUrl\": null,      \"weight\": {        \"value\": 0,        \"units\": \"ounces\"      },      \"quantity\": 1,      \"unitPrice\": -20.55,      \"taxAmount\": null,      \"shippingAmount\": null,      \"warehouseLocation\": null,      \"options\": [],      \"productId\": 123456,      \"fulfillmentSku\": \"SKU-Discount\",      \"adjustment\": true,      \"upc\": null    }  ],  \"amountPaid\": 218.73,  \"taxAmount\": 5,  \"shippingAmount\": 10,  \"customerNotes\": \"Thanks for ordering!\",  \"internalNotes\": \"Customer called and would like to upgrade shipping\",  \"gift\": true,  \"giftMessage\": \"Thank you!\",  \"paymentMethod\": \"Credit Card\",  \"requestedShippingService\": \"Priority Mail\",  \"carrierCode\": \"fedex\",  \"serviceCode\": \"fedex_2day\",  \"packageCode\": \"package\",  \"confirmation\": \"delivery\",  \"shipDate\": \"2015-07-02\",  \"weight\": {    \"value\": 25,    \"units\": \"ounces\"  },  \"dimensions\": {    \"units\": \"inches\",    \"length\": 7,    \"width\": 5,    \"height\": 6  },  \"insuranceOptions\": {    \"provider\": \"carrier\",    \"insureShipment\": true,    \"insuredValue\": 200  },  \"internationalOptions\": {    \"contents\": null,    \"customsItems\": null  },  \"advancedOptions\": {    \"warehouseId\": 98765,    \"nonMachinable\": false,    \"saturdayDelivery\": false,    \"containsAlcohol\": false,    \"mergedOrSplit\": false,    \"mergedIds\": [],    \"parentId\": null,    \"storeId\": 12345,    \"customField1\": \"Custom data that you can add to an order. See Custom Field #2 & #3 for more info!\",    \"customField2\": \"Per UI settings, this information can appear on some carrier's shipping labels. See link below\",    \"customField3\": \"https://help.shipstation.com/hc/en-us/articles/206639957\",    \"source\": \"Webstore\",    \"billToParty\": null,    \"billToAccount\": null,    \"billToPostalCode\": null,    \"billToCountryCode\": null  }}", System.Text.Encoding.Default, "application/json"))

This is really a stupid question but what I want to do is add variables to this string content. The problem is that I don't quite understand how to read or how this string is formatted (Specifically the "\"). I usually add @ in a string if I need to add "\" so I'm not sure if the "\" should be included in the string in some parts or that is used in this example to concat.

Can someone help how I can add variables to this string content?

Thank you for the help!

Answer 1

From MSDN

Provides HTTP content based on a string.

Very basic use of StringContent is to send data to server while accessing any API.

Here I am taking a simple example of Login API in a system.

// Following is the key value pairs (data) which we need to send to server via API.
Dictionary<string, string> jsonValues = new Dictionary<string, string>();
jsonValues.Add("username", "testuser");
jsonValues.Add("password", "XXXXXXXXXX"); // better to encrypt passwod before sending to API.

HttpClient client = new HttpClient();

// Used Newtonsoft.Json library to convert object to json string. It is available in Nuget package.
StringContent sc = new StringContent(JsonConvert.SerializeObject(jsonValues), UnicodeEncoding.UTF8, "application/json");
HttpResponseMessage response = await client.PostAsync(webAddress, sc);

string content = await response.Content.ReadAsStringAsync();
Console.WriteLine("Result: " + content);

Check this SO post for some other explanation from other users.