Qt开发：窗体布局(QFormLayout)

一、QFormLayout介绍

窗体布局管理器QFormLayout用来管理表单的输入部件以及与它们相关的标签，窗体布局管理器将它的子部件分为两列，左边是一些标签，右边是一些输入部件。

二、QFormLayout的常用函数

AddRow()常用的重载函数

void addRow(QWidget *label, QWidget *field)
void addRow(QWidget *label, QLayout *field)
void addRow(const QString &labelText, QWidget *field)
void addRow(const QString &labelText, QLayout *field)

代码示例如下：

#include "main_window.h"

MainWindow::MainWindow(QWidget *parent)
    : QWidget(parent)
{
   QLineEdit *pUserEdit = new QLineEdit(this);
   QLineEdit *pPasswordEdit = new QLineEdit(this);
   QLineEdit *pVerifyLineEdit = new QLineEdit(this);

   QFormLayout *pLayout = new QFormLayout(this);
   pLayout->addRow("用户名:", pUserEdit);
   pLayout->addRow("密码:", pPasswordEdit);
   pLayout->addRow("验证码:", pVerifyLineEdit);
   pLayout->setSpacing(10);
   pLayout->setMargin(10);

   this->setLayout(pLayout);
}

设置换行策略，输入框始终在标签旁边

void setRowWrapPolicy(QFormLayout::RowWrapPolicy policy)

输入框始终在标签下边

pLayout->setRowWrapPolicy(QFormLayout::RowWrapPolicy::WrapAllRows);

标签有足够的空间适应，如果最小大小比可用空间大，则输入框则会被换到

#include "main_window.h"

MainWindow::MainWindow(QWidget *parent)
    : QWidget(parent)
{
   this->setFixedWidth(200);

   QLineEdit *pUserEdit = new QLineEdit(this);
   QLineEdit *pPasswordEdit = new QLineEdit(this);
   QLineEdit *pVerifyLineEdit = new QLineEdit(this);

   QFormLayout *pLayout = new QFormLayout(this);
   pLayout->addRow("用户名11111111111111111:", pUserEdit);
   pLayout->addRow("密码:", pPasswordEdit);
   pLayout->addRow("验证码:", pVerifyLineEdit);
   pLayout->setRowWrapPolicy(QFormLayout::RowWrapPolicy::WrapLongRows);
   pLayout->setSpacing(10);
   pLayout->setMargin(10);

   this->setLayout(pLayout);
}

三、QFormLayout布局管理器的嵌套的示例

#include "main_window.h"

MainWindow::MainWindow(QWidget *parent)
    : QWidget(parent)
{
   QLineEdit *pUserEdit = new QLineEdit(this);
   QLineEdit *pPasswordEdit = new QLineEdit(this);
   QLineEdit *pVerifyLineEdit = new QLineEdit(this);
   QLineEdit *pTestEdit = new QLineEdit(this);

   QVBoxLayout *pVLayout = new QVBoxLayout();
   pVLayout->addWidget(pVerifyLineEdit);
   pVLayout->addWidget(pTestEdit);

   QFormLayout *pLayout = new QFormLayout(this);
   pLayout->addRow("用户名:", pUserEdit);
   pLayout->addRow("密码:", pPasswordEdit);
   pLayout->addRow("验证码:", pVLayout);
   pLayout->setSpacing(10);
   pLayout->setMargin(10);

   this->setLayout(pLayout);
}