Release 10.1A: OpenEdge Development:
.NET Open Clients

Passing INTPUT-OUTPUT parameters

Passing an INPUT-OUTPUT parameter requires several steps to provide a value as input to an application service procedure or user-defined function, then to return a value as output using the same parameter.

To pass an INPUT parameter:

Create and initialize a variable for the parameter of the correct .NET data type (see the "Creating variables for parameters" section).
Add the parameter to a ParamArray object (see the "Setting up a parameter array" section).
Run the procedure or user-defined function (see the "Running procedures and user-defined functions" section).
Get the output value from the ParamArray (see the "Getting OUTPUT parameter values" section). You might also want to reset the variable.

Example 8–5 passes an INPUT-OUTPUT integer parameter that does not support the Unknown value (?):

Example 8–5: Passing an INPUT-OUTPUT parameter using the .NET OpenAPI

// Define and initialize the variable for the input-output parameter Int32 CustomerNumber = 33; // Create the ParamArray ParamArray parms = new ParamArray(1); // Add the input-output parameter to the ParamArray parms.AddInteger(0, CustomerNumber, ParamArrayMode.INPUT_OUTPUT); // Run the procedure ... // Fill output parameter // The output value is always returned as an Object // You need to cast the Object before assigning it. CustomerNumber = (Int32) parms.GetOutputParameter(0);