Hello
In my program I have two Buttons:
Button1 adds one item to my model
Button2 imports a file with x items to my model
Both buttons use the same method (appendRow) to append data to the model. The only difference is that for Button2 I use a "FOR-loop".
I use QStandardItemModel, QTreeview and QStandardItem

Problem:
If i use Button1 to add one item data is visible in a very short time.
If I use Button2 to import x=1000 items. The first import takes let me say 1 second. The second import of 1000 items takes 2 seconds. the third 3 seconds,...
Than if I use Button1 to add 1 item again it takes also 3 seconds!

Questions:
Why takes it the same time to add one or 1000 items? The time only depends on the number of data in the model.
What can I do to reduce the time for adding only one item?

Thank you for your help and sorry for my bad English!

PS: this is my very first Qt Project so please don't be too hard to me ; )