一个如何从左上到右填充QGridLayout? [英] How does one fill a QGridLayout from top-left to right?

问题描述

我想用QWidgets填充QGridLayout. QWidgets需要以从左上到右上的方式显示，并在每行用QWidgets填充后继续向下向下填充.一个类似且熟悉的GUI的示例是Apple如何在iPhone或iPad的主屏幕上对其应用程序进行排序.这些应用程序从左上到右上，并在每行填满后继续向下.

I would like to fill a QGridLayout with QWidgets. The QWidgets need to appear in a top-left to top-right fashion and proceed to fill the down downwards after each row is filled with QWidgets. An example of a similar and familiar GUI is how Apple sorts its apps on the iPhone or iPad's home screen. The apps go top-left to top-right and proceed to go downward after each row is filled.

现在，每当我添加元素时，它们就会占据整个屏幕，并且/或者不会彼此相邻添加.

Right now, whenever I add elements, they take up the entirety of the screen and/or aren't added next to each other.

这是我在做什么的示例代码

This is example code of what I am doing

m_gridLayout = new QGridLayout(this);
this->setLayout(m_gridLayout);
m_gridLayout->addWidget(widgetToBeAdded, m_currentRow, m_currentColumn, Qt::AlignLeft);

我继续按预期更新m_currentColumn和m_currentRow.在一定数量的列之后，我告诉它更改为下一行，什么也没有发生.我已经通过调试确认，它实际上是在吐出正确的行和列.)

I proceed to update m_currentColumn and m_currentRow as expected. After a certain amount of columns, I tell it to change to the next row, and nothing happens. I have confirmed through debugging that it is infact spitting out the correct rows and columns.)

最终，我将需要戴上QScrollArea，以便人们可以向下滚动网格.

Eventually, I will need to throw on a QScrollArea so that one can scroll down the grid.

每个QWidget的大小将相同.如果我在正确排序网格方面能获得任何帮助，将不胜感激.

The size of each QWidget will be the same. If I could get any help in regards to sorting the grid properly, it would be much appreciated.

使用下面的答案，我设法使我的物品按正确的顺序排序.但是，在垂直方向上的所有元件之间存在大量空间.正如我想的那样，这不能通过更改verticalSpacing属性来消除.有人知道如何进行吗?

Using the answer below, I have managed to get my items to sort in the correct order. However, there is a large amount of space in between all elements in the vertical direction. This is not obviated by changing the verticalSpacing property, as I would think. Does anyone know how to proceed?

推荐答案

编写自己的网格布局，如下所示:

Write your own grid layout, something like this:

标题

#ifndef MY_GRID_LAYOUT_H
#define MY_GRID_LAYOUT_H

#include <QGridLayout>

class my_grid_layout : public QGridLayout
{
public:
    my_grid_layout(QWidget *parent, int max_column_count );
    ~my_grid_layout();

    void add_widget( QWidget* p_widget );

private:
    int m_max_column_count;
};

#endif // MY_GRID_LAYOUT_H

来源

#include "my_grid_layout.h"

my_grid_layout::my_grid_layout(QWidget *parent, int max_column_count)
    : QGridLayout(parent)
{
    m_max_column_count = max_column_count;
}

my_grid_layout::~my_grid_layout()
{

}

void my_grid_layout::add_widget( QWidget* p_widget )
{
    int current_row = 0;
    int current_column = 0;

    while( itemAtPosition(current_row, current_column) != 0 )
    {
        if( current_column == (m_max_column_count-1) )
        {
            current_column = 0;
            ++current_row;
        }
        else
        {
            ++current_column;
        }
    }

    QGridLayout::addWidget( p_widget, current_row, current_column );
}

在主窗口中测试

#include "test_1.h"

Test_1::Test_1(QWidget *parent, Qt::WFlags flags)
    : QMainWindow(parent, flags)
{
    m_grid_layout = new my_grid_layout(this,4);

    m_grid_layout->add_widget( new QPushButton( "Widget 0", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 1", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 2", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 3", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 4", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 5", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 6", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 7", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 8", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 9", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 10", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 11", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 12", this ) );
    m_grid_layout->add_widget( new QPushButton( "Widget 13", this ) );



    QWidget* central_widget = new QWidget(this);
    central_widget->setLayout(m_grid_layout);

    setCentralWidget(central_widget);
}

Test_1::~Test_1()
{

}

结果

虽然在某个位置已经有一个项目，但是切换到网格布局中的下一个位置，在我的示例中，该位置的最大列数为4.我只是切换到下一列，直到到达第四列.然后，我将该列重置为0，然后切换到下一行.只要已经有一个项目，我就这样做.一旦那个地方没有物品，我就把小部件放在那里.

While there is already an item at a certain position, switch to the next position in the grid layout, which has a maximum column count of 4 in my example. I just switch to next column until I reached the 4th column. Then I reset the column to 0 and switch to the next row. I do this as long as there is already an item. As soon as there is no item in that place, I put my widget there.

这只是一个简单的示例，但也许足以供您使用.

This is just a quick example, but maybe it's enough for you to work with.

您应该通过错误处理来增强它，当心无休止的循环等等……

You should enhance it by error handling, watch out for endless loop and such...

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