Qt 컨트롤에 배경 이미지 넣기

1.  QPushButton에 배경이미지 넣기

void setButtonBackImage(QPushButton *button,QString image,int sizeW, int sizeH)
{
  //163,163 Is the original resolution , Here's a little adjustment .
  QPixmap pixmap(image);
  QPixmap fitpixmap=pixmap.scaled(163,163).scaled(sizeW, sizeH, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
  button->setIcon(QIcon(fitpixmap));
  button->setIconSize(QSize(sizeW,sizeH));
  button->setFlat(true);// This is the sentence that can make the button transparent , use png It's very useful when using pictures
  button->setStyleSheet("border: 0px");// Remove borders , Cancel the click effect
}

2. QWidget에 배경이미지 넣기

this->setAutoFillBackground(true);    //Widget When adding background pictures , This must be true .
QPixmap pixmap(":/images/bg_news.png");
QPixmap fitpixmap=pixmap.scaled(1200, 1200).scaled(config->mainWindowW,config->mainWindowH, Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
QPalette palette;
palette.setBrush(QPalette::Background, QBrush(fitpixmap));
this->setPalette(palette);

3. QLabel 에 배경이미지 넣기

QPixmap pixmap(normalIcon);
QPixmap fitpixmap=pixmap.scaled(labelIcon->width(), labelIcon->height(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
labelIcon->setPixmap(fitpixmap);​

4. QSS  StyleSheet를 이용하여 배경이미지 넣기 (사이즈 변경 불가)

lastBtn->setStyleSheet("background-image: url(:/images/btn_previous_normal.png);border: 0px");

5. QPixmap 이미지 회전하기

QMatrix leftmatrix;
leftmatrix.rotate(270);
ui->label->setPixmap(pixmap.transformed(leftmatrix, Qt::SmoothTransformation));