CODEWITHSUNDEEP
amazon-web-servicesaws-lambdaaws-sdkaws-api-gateway
ABHILASH SOMA
ABHILASH SOMA

Reputation: 41

pass QueryString Paramaters from API Gateway to AWS Lambda c#

i am trying to call AWS Lambda using APIGateway and it returns HTML Code. it works fine when i dont pass any parameters, but i want to pass some QueryString parameters and use them in Lambda. i have my Lambda in C# and i see parameters being passed from API

response from API "headers": {}, "QueryStringParameters": { "Environment": "xzc" }, "PathParameters": {} }

In Lambda, the APIGatewayProxyRequest is coming as null API Lambda public string FunctionHandler(APIGatewayProxyRequest request, ILambdaContext context)

how do i read the querystring parameters in AWS Lambda in C#

Upvotes: 4

Views: 3493

Answers (4)

Zbigniew Ledwoń
Zbigniew Ledwoń

Reputation: 682

Looks like you just need to check Use Lambda Proxy integration in Integration Request in your API Gateway resource config.

also

you should include:

using Amazon.Lambda.APIGatewayEvents;

and your handler function header should like something like this:

public APIGatewayProxyResponse FunctionHandler( APIGatewayProxyRequest input, ILambdaContext context)

then you can access your query string parameters with:

input.QueryStringParameters

Upvotes: 2

Anugrah A
Anugrah A

Reputation: 29

Explaining for more than 1 input parameters as sometimes that is also a problem to developers:

Step 01: This should be your C-Sharp method

public string FunctionHandler(string strEnvironmentA, string strEnvironmentB, ILambdaContext context);

Step 02: In API > GET Method Execution > Method Request add query string parameter for

  • strEnvironmentA
  • strEnvironmentB

Step 03: In API > GET Method Execution > Integration Request > Body Mapping Template add this application/json template

"$input.params('strEnvironmentA')" 
"$input.params('strEnvironmentB')"

Upvotes: 1

Safu
Safu

Reputation: 1

Do something like this:

public string FunctionHandler(string input, ILambdaContext context);

And then you can pass the input in the request body instead of query string params.

Upvotes: 0

MattKind
MattKind

Reputation: 1

if (request.QueryStringParameters != null)
{
    queryStringParameters = request.QueryStringParameters;
    foreach (var item in queryStringParameters)
    {
        Console.WriteLine($"QueryStringParameter - " + item.Key + ":" + item.Value);
    }
}

Upvotes: -1

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