Delphi SOAP Client将项目添加到动态数组

Question

I'm currently developing a client for a SOAP service.

The WSDL import works fine, but I'm facing the problem that I need to add items to a dynamic array.

The declaration in delphi:

    Array_Of_attributWS = array of attributWS;

    dienstleistungWS = class(TRemotable)
      private
         [..]
      public
         [..]
      published
        property attributeWS: Array_Of_attributWS
         Index(IS_OPTN or IS_UNBD or IS_NLBL or IS_UNQL)read GetattributeWS
         write SetattributeWS stored attributeWS_Specified;

I want to add an item to attributeWS from an other unit. To add an item I use this code:

    SetLength(dynArray, Length(dynArray)+1);
    dynArray[High(dynArray)] := item;

But it wont let me, I get the following error: E2197 Constant object cannot be passed as var parameter

Is there a way to add an item easy to the dynamic array? Or is there a way to cast the array to a list so that I can just do .Append(item)?

Delphi Version XE6 Thanks!

Answer 1

If you check the SetattributeWS implementation you will see it simply gets your dynamic array as a const parameter, stores it and marks an internal boolean variable as true (indicating the parameter has been informed).

The const part is the one that causes the E2197 error you are seeing.

The best option is to use a local dynamic array variable of the same type and then:

1. set its length to the actual length of attributeWS + 1.
2. copy the original items from attributeWS to the local variable, and then add the new item.
3. assign this variable to the attributeWS property.

Actually, it would be better to not assign the dynamic array to the request property until you have it filled with all the necessary elements, but that may depend on your needs.