how to preview of image in QFileDialog by default

[yoll522]

yes

but I going to look QFileIconProvider document, it have "icon" function,

it is to provide systematic image, like the following instructions

enum QFileIconProvider::IconType
QFileIconProvider::Computer	
QFileIconProvider::Desktop	
QFileIconProvider::Trashcan	
QFileIconProvider::Network	
QFileIconProvider::Drive	
QFileIconProvider::Folder	
QFileIconProvider::File

enum QFileIconProvider::IconType
QFileIconProvider::Computer	
QFileIconProvider::Desktop	
QFileIconProvider::Trashcan	
QFileIconProvider::Network	
QFileIconProvider::Drive	
QFileIconProvider::Folder	
QFileIconProvider::File

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I try it to use, this is my code

QFileIconProvider fileIcon;
ui->pushButton->setIcon(fileIcon.icon(QFileInfo("1.jpg")));

but I got this answer
002.jpg

it also have no preview Image

maybe I was wrong about something

could you please guide me

thanks you very much