Hello. I already did it. But I have determined that events belong to different objects.
After this code:

Qt Code:
  1. cc++;
  2. qDebug() << cc;
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I added the following code:
Qt Code:
  1. qDebug() << watched->metaObject()->className();
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Received a result:
Forum_question_2_1.png

Therefore, in eventFilter, I added the following kind of verification:
Qt Code:
  1. QString tempStr = "QWidgetWindow";
  2. if (watched->metaObject()->className() == tempStr){
  3. // code here
  4. }
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In this case, the issue is resolved. But I do not know if it is correct to do so?