QLabel需要完整的空间

Question

我有一个包含QVBoxLayout的QWidget，该布局包含QLabel和QToolButtons。我的问题是，QLabel占用了所有空间。我找到的唯一解决方案是将maximumHeight设置为QLabel，但如果我这样做，Qt :: AlignTop将不再起作用。

main.cpp中：

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QWidget window_main;

    QWidget *widget_steps = new QWidget(&window_main);
    widget_steps->setFixedWidth(75);
    widget_steps->move(QPoint(0, 0));
    widget_steps->setStyleSheet("background-color: red;");

    QVBoxLayout *layout_steps = new QVBoxLayout(widget_steps);
    layout_steps->setContentsMargins(0, 0, 0, 0);
    layout_steps->setSpacing(0);

    QLabel *label_steps_start = new QLabel("steps:");
    label_steps_start->setAlignment(Qt::AlignHCenter | Qt::AlignTop);
    label_steps_start->setStyleSheet("background-color: blue;");
    layout_steps->addWidget(label_steps_start);

    QToolButton *tbutton_step1 = new QToolButton();
    layout_steps->addWidget(tbutton_step1);

    QToolButton *tbutton_step2 = new QToolButton();
    layout_steps->addWidget(tbutton_step2);

    QToolButton *tbutton_step3 = new QToolButton();
    layout_steps->addWidget(tbutton_step3);


    window_main.showMaximized();

    return a.exec();
}

这张图片显示了QLable需要多少空间（蓝色空间）：

所以请帮助减少QLable占用的空间：）

Answer 1

您可以做的一种方法是在QVBoxLayout中设置该特定小部件的延伸因子。您可以在here。

中找到相关文档

基本上，当您添加小部件时，您可以设置它，例如：

#include <QtWidgets/QApplication>
#include <QtWidgets/QLabel>
#include <QtWidgets/QToolButton>
#include <QtWidgets/QVBoxLayout>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QWidget window_main;

    QWidget *widget_steps = new QWidget(&window_main);
    widget_steps->setFixedWidth(75);
    widget_steps->move(QPoint(0, 0));
    widget_steps->setStyleSheet("background-color: red;");

    QVBoxLayout *layout_steps = new QVBoxLayout(widget_steps);
    layout_steps->setContentsMargins(0, 0, 0, 0);
    layout_steps->setSpacing(0);

    QLabel *label_steps_start = new QLabel("steps:");
    label_steps_start->setAlignment(Qt::AlignHCenter | Qt::AlignTop);
    label_steps_start->setStyleSheet("background-color: blue;");
    layout_steps->addWidget(label_steps_start, 3, Qt::AlignTop);
    layout_steps->addStretch();

    QToolButton *tbutton_step1 = new QToolButton();
    layout_steps->addWidget(tbutton_step1, 1);

    QToolButton *tbutton_step2 = new QToolButton();
    layout_steps->addWidget(tbutton_step2, 1);

    QToolButton *tbutton_step3 = new QToolButton();
    layout_steps->addWidget(tbutton_step3, 1);


    window_main.showMaximized();

    return a.exec();
}

Answer 2

您的问题是工具按钮的大小是固定的，因此在调整大小时，标签是唯一可以增长的类型：因此： 添加标签后，将拉伸添加到布局：

layout_steps->addWidget(label_steps_start);
layout_steps->addStretch();

修改后的代码 - 在底部添加拉伸。标签尺寸保持固定，按钮保留在其下方。为了测试，我已经移除了外面的整个主窗口。

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    QWidget *widget_steps = new QWidget;
    widget_steps->setFixedWidth(75);
    widget_steps->move(QPoint(0, 0));
    widget_steps->setStyleSheet("background-color: red;");

    QVBoxLayout *layout_steps = new QVBoxLayout(widget_steps);
    layout_steps->setContentsMargins(0, 0, 0, 0);
    layout_steps->setSpacing(0);

    QLabel *label_steps_start = new QLabel("steps:");
    label_steps_start->setAlignment(Qt::AlignHCenter | Qt::AlignTop);
    label_steps_start->setStyleSheet("background-color: blue;");
    layout_steps->addWidget(label_steps_start);
    //--- Removed.... layout_steps->addStretch();

    QToolButton *tbutton_step1 = new QToolButton();
    layout_steps->addWidget(tbutton_step1);

    QToolButton *tbutton_step2 = new QToolButton();
    layout_steps->addWidget(tbutton_step2);

    QToolButton *tbutton_step3 = new QToolButton();
    layout_steps->addWidget(tbutton_step3);
    layout_steps->addStretch(); //<----- Added!
    widget_steps->show();

    return a.exec();
}