QtUI设计：设置控件透明

QT设置按钮控件透明：

        代码：

    //设置按钮 背景 前景
    this->ui->ShowCvRGB->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(100,100,100,100)"));
    // 第一个 为前景色；第二个 为北京色； 透明度 为a
    this->ui->ShowPcdFile->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(100,100,100,100)"));
    this->ui->QwtPlotDraw->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(0,0,0,0)"));

    this->ui->Train->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(100,100,100,100)"));
    this->ui->Classify->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(100,100,100,100)"));
    this->ui->Abnormal->setStyleSheet(QString("color:rgba(255,255,255,255);background-color:rgba(100,100,100,100)"));