如何删除我提供透明背景图像的QDialog的边框？

Question

I intended to make a un-rectangle QDialog , so I paint a png image by override QDialog::paintEvent .Everything is okay except there is a gray border shown arrond the dialog.Like this:

I am sure that border is not belong to the image,and I had setWindowFlags(Qt::FramelessWindowHint) and setAttribute(Qt::WA_TranslucentBackground, true) .I tried to set a qss like border-width: 0px but didn't work. Is there any way to remove the border?And why it is shown?

Answer 1

You can create a borderless dialog by setting Qt::FramelessWindowHint window flag :

setWindowFlags(Qt::Window | Qt::FramelessWindowHint);

To make it transparent you should set these attributes :

setAttribute(Qt::WA_NoSystemBackground);
setAttribute(Qt::WA_TranslucentBackground);
setAttribute(Qt::WA_PaintOnScreen);