Expression does not produce a value,I don't know why this problem arises?

Hello everyone, I have a question here. I want to store the values of different A column corresponding to the same B column in a Dictionary<String, List> variable. The key should be the value from the B column, and the value should be a list of values from the A column. However, when I perform the assignment activity, it throws an error. What could be the reason for this?



Can you try as the following using Assign activity?

dictAB(rowA) = rowB

Or if you want to use Add method, it’s necessary to use InvokeMethod because Assign doesn’t support void type method.


Hi @shenyu ,
Before adding items to the dictionary it must be initialized. The default value of the Dictionar object is Nothing.

To initialize it you can use an Assign activity or define default value in the Variables pane.

The value should be new Dictionary(Of String, List of String), because your key is string and value is List of String .

I switched to the Invoke Code activity, why does it give me an ‘Option Strict On disallows late binding’ error?


Can you try to modify 4th line as the following?

For Each row As DataRow In filiteredData.Rows


Why did I report an error when I called the add method in the list through the invoke method activity

‘List ` 1’ does not have a public instance method named ‘Add’ that matches the parameter types, generic type parameters, and generic type constraints provided to the InvokeMethod ‘calling method’
I wrote an example based on the official demo and still reported an error. I don’t understand


Can you check/share content of parameter property?


I just created a new list and called the add method through the invoke method without setting any parameters


It’s necessary to set parameters as the following.