Regarding the Base Class adding to User define Class

[Pradeep Kumar]

As reading the documentation, i came to know we need to inherit from BaseExternWidget and implement one of the method.

we need to copy the BaseExternWidget to our project file?.
And inherit the the user defined class from BaseExternWidget?.

Then do our implementation by creating the user defined classes according to the requirements, in our project and then compile as .dll

can you provide the guidance in understanding the documentation about BaseExternWidget?

[mkoller]

In the WinCC_OA installation, you find the file 3.14/api/README.NT
This explains to use the "newEWO.cmd" script to create a sample template ewo.
This simple ewo can already be compiled and used and the code includes additional comments and TODO commented
lines explaining what needs to be done.
Just follow these, it's really simple.

[Pradeep Kumar]

I was going through the document from WinCC OA.

Please find the attached image and let me know. As per the title of the Topic i mentioned, whether my understanding is right?.

[fmulder]

The attached document is a) quite old and b) Windows only.
Still, it might give you an idea and I guess that it should still work.

I'm not an active Qt developer but did this a couple of years ago to play with the Ewos. Hope that it helps you.

Yes, Qt is beautiful !
https://www.winccoa.com/fileadmin/image ... S_EWO.docx

[Pradeep Kumar]

Thanks for the document.

And the image attached in the previous post , what does it infer then , which method do i need to follow?

[fmulder]

The bitmap just says that your C++ code should derive from BaseExternWidget just like my example does.

I'd suggest that you use the 'newEwo.cmd' batch file in your API folder. This shoudl give you the proper framework for starting.

Personally : I started using Qt Developer to first learn Qt. Then, after going through some of the samples, you can try to write an EWO.

Good luck

[Pradeep Kumar]

K i will go though the documentation and is newEWO.cmd mandatory to run to create the EWO?.

[fmulder]

No, the 'newxxx' batchfiles are just quite helpfull. You can use them or can decide to copy and modify an earlier project.