使用QTabWidget，给每个tab添加了图标之后，文字和图标之间有间距，没有完美居中显示。

遇到此问题，尝试了多种办法，均不理想，最终自定义QTabBar，重绘tab，完美解决。

#include <QTabBar>
#include <QStylePainter>class MyTabBar : public QTabBar {
public:MyTabBar(QWidget *parent = nullptr) : QTabBar(parent){}protected:void paintEvent(QPaintEvent *) override{QStylePainter painter(this);for (int index = 0; index < this->count(); ++index) {QStyleOptionTab opt;initStyleOption(&opt, index);// 计算图标和文字的长度（含间距）int iconTextWidth = opt.iconSize.width()+ opt.fontMetrics.horizontalAdvance(opt.text)+ 4; // 4 是图标和文字的间距int x = (opt.rect.width() - iconTextWidth) / 2 + opt.rect.width() * index;painter.save();// 指定各状态下的按钮状态if (opt.state & QStyle::State_Selected) { // 按下状态painter.setPen(QColor(255, 255, 255));painter.fillRect(rect, QColor(31, 68, 133));} else if (opt.state & QStyle::State_MouseOver) { // 鼠标停留状态painter.setPen(QColor(255, 255, 255));painter.fillRect(rect, QColor(33, 72, 141));} else if (!(opt.state & QStyle::State_Enabled)) { // 禁止状态painter.setPen(QColor(255, 255, 255, 153));painter.fillRect(rect, QColor(84, 123, 192));} else { // 正常状态（默认）painter.setPen(QColor(255, 255, 255));painter.fillRect(rect, QColor(41, 90, 176));}QRect iconRect(x, (opt.rect.height() - opt.iconSize.height()) / 2,opt.iconSize.width(), opt.iconSize.height());painter.drawPixmap(iconRect, opt.icon.pixmap(opt.iconSize));QRect textRect(iconRect.right() + 4, 0,opt.rect.width() * (index + 1) - iconRect.right() - 4,opt.rect.height());painter.drawText(textRect, Qt::AlignVCenter | Qt::AlignLeft, opt.text);painter.restore();}}
};

调用：

ui->tabWidget->setTabBar(new MyTabBar(this));