【转】QGridLayout 详解

红太狼 2022-11-17 05:23 354阅读 0赞

## 转自：[https://blog.csdn.net/u013928315/article/details/78123573][https_blog.csdn.net_u013928315_article_details_78123573] ##

## 一、QGridLayout属性介绍 ##

1、QGridlayout以方格的形式管理窗口部件，先看QGridLayout的属性，如下图

![a41a648f9e0c85553c25f53562c3fab2.png][]

2、各个参数的介绍

layoutLeftMargin ...至layoutBottomMargin在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setContentsMargins(20, 10, 10, 10);

学过CSS都知道，这是设置一个元素所有外边距的宽度，或者设置各边上外边距的宽度

On most platforms, the margin is 11 pixels in all directions.

HorizontalSpacing...至VerticalSpacing在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setHorizontalSpacing(6);

gridLayout->setVerticalSpacing(6);

这是设置两个控件之间的水平和竖直距离

LayoutRowStretch在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setRowStretch(0, 1);

gridLayout->setRowStretch(1, 1);

gridLayout->setRowStretch(2, 1);

表示在第0行、第1行、第2行 在竖直方向的空间比例分配，大家稍微改一下参数就能看出来效果

LayoutColumnStretch在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setColumnStretch(1, 1);

表示设置第0列、第1列两者在水平方向的空间比例分配。

LayoutRowMinimumHeight在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setRowMinimumHeight(0, 1);

gridLayout->setRowMinimumHeight(1, 2);

gridLayout->setRowMinimumHeight(2, 3);

表示在第0行、第1行、第2行的最小高度是1pixels,2pixels,3pixels

LayoutColumnMinimumWidth在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setColumnMinimumWidth(0, 4);

gridLayout->setColumnMinimumWidth(1, 5);

表示设置第0列、第1列的最小宽度是4pixels、5pixels

LayoutSizeConstraint在ui\_MainWindow.h中自动生成的代码是：

gridLayout->setSizeConstraint(QLayout::SetDefaultConstraint);

This property holds the resize mode of the layout.看下表

### enum QLayout::SizeConstraint ###

The possible values are:

Constant Value Description

<table> 
 <tbody> 
  <tr> 
   <td>QLayout::SetDefaultConstraint</td> 
   <td>0</td> 
   <td>The main widget's minimum size is set to&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayout.html#minimumSize" rel="nofollow">minimumSize</a>(), unless the widget already has a minimum size.</td> 
  </tr> 
  <tr> 
   <td>QLayout::SetFixedSize</td> 
   <td>3</td> 
   <td>The main widget's size is set to&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayoutitem.html#sizeHint" rel="nofollow">sizeHint</a>(); it cannot be resized at all.</td> 
  </tr> 
  <tr> 
   <td>QLayout::SetMinimumSize</td> 
   <td>2</td> 
   <td>The main widget's minimum size is set to&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayout.html#minimumSize" rel="nofollow">minimumSize</a>(); it cannot be smaller.</td> 
  </tr> 
  <tr> 
   <td>QLayout::SetMaximumSize</td> 
   <td>4</td> 
   <td>The main widget's maximum size is set to&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayout.html#maximumSize" rel="nofollow">maximumSize</a>(); it cannot be larger.</td> 
  </tr> 
  <tr> 
   <td>QLayout::SetMinAndMaxSize</td> 
   <td>5</td> 
   <td>The main widget's minimum size is set to&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayout.html#minimumSize" rel="nofollow">minimumSize</a>() and its maximum size is set to<a href="http://qimo601.iteye.com/admin/blogs/1413634/qlayout.html#maximumSize" rel="nofollow">maximumSize</a>().</td> 
  </tr> 
  <tr> 
   <td>QLayout::SetNoConstraint</td> 
   <td>1</td> 
   <td> <p>The widget is not constrained.</p> <p>&nbsp;</p> <p>&nbsp;</p> </td> 
  </tr> 
 </tbody> 
</table>

## QFormLayout属性介绍 ##

1、QFormLayout类管理输入型控件和它的label组成的那些form表格，包括它的界面参数如下图

![6309abea4a47c8e8fe291da45b66c17e.png][]

2、界面中对应的代码如下表，

Cpp代码   ![收藏代码][5cf278eacb6d6b916f9d2a8906cbe561.png]

1.  formLayout = new QFormLayout(widget1);  
2.          formLayout->setSpacing(6);  
3.          formLayout->setContentsMargins(11, 11, 11, 11);  
4.          formLayout->setObjectName(QString::fromUtf8("formLayout"));  
5.          formLayout->setFieldGrowthPolicy(QFormLayout::ExpandingFieldsGrow);  
6.          formLayout->setRowWrapPolicy(QFormLayout::DontWrapRows);  
7.          formLayout->setContentsMargins(0, 0, 0, 0);  
8.          label\_4 = new QLabel(widget1);  
9.          label\_4->setObjectName(QString::fromUtf8("label\_4"));  
10.   
11.         formLayout->setWidget(0, QFormLayout::LabelRole, label\_4);  
12.   
13.         lineEdit = new QLineEdit(widget1);  
14.         lineEdit->setObjectName(QString::fromUtf8("lineEdit"));  
15.   
16.         formLayout->setWidget(0, QFormLayout::FieldRole, lineEdit);  
17.   
18.         label\_5 = new QLabel(widget1);  
19.         label\_5->setObjectName(QString::fromUtf8("label\_5"));  
20.   
21.         formLayout->setWidget(1, QFormLayout::LabelRole, label\_5);  
22.   
23.         comboBox = new QComboBox(widget1);  
24.         comboBox->setObjectName(QString::fromUtf8("comboBox"));  
25.   
26.         formLayout->setWidget(1, QFormLayout::FieldRole, comboBox);

**3、其中值得一说的是：LayoutFieldGrowthPolicy属性**

### enum QFormLayout::FieldGrowthPolicy ###

This enum specifies the different policies that can be used to control the way in which the form's fields grow.

Constant Value Description

<table> 
 <tbody> 
  <tr> 
   <td>QFormLayout::FieldsStayAtSizeHint</td> 
   <td>0</td> 
   <td>The fields never grow beyond their&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qwidgetitem.html#sizeHint" rel="nofollow">effective size hint</a>. This is the default for<a href="http://qimo601.iteye.com/admin/blogs/1413634/qmacstyle.html" rel="nofollow">QMacStyle</a>.</td> 
  </tr> 
  <tr> 
   <td>QFormLayout::ExpandingFieldsGrow</td> 
   <td>1</td> 
   <td>Fields with an horizontal&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qsizepolicy.html" rel="nofollow">size policy</a>&nbsp;of&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qsizepolicy.html#Policy-enum" rel="nofollow">Expanding</a>&nbsp;or&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qsizepolicy.html#Policy-enum" rel="nofollow">MinimumExpanding</a>&nbsp;will grow to fill the available space. The other fields will not grow beyond their effective size hint. This is the default policy for Plastique.</td> 
  </tr> 
  <tr> 
   <td>QFormLayout::AllNonFixedFieldsGrow</td> 
   <td>2</td> 
   <td>All fields with a size policy that allows them to grow will grow to fill the available space. This is the default policy for most styles.</td> 
  </tr> 
 </tbody> 
</table>

**4、还有一个属性值得说：LayoutRowWrapPolicy**

This property holds the way in which the form's rows wrap.

//这个属性设置了表格如何排版各个元素

If you want to display each label above its associated field (instead of next to it), set this property to WrapAllRows.

//如果你想把每个标签放在相关字段的上方，而不是和它相邻，就设置这个属性值为WrapAllRows。

### enum QFormLayout::RowWrapPolicy ###

This enum specifies the different policies that can be used to control the way in which the form's rows wrap.

Constant Value Description

<table> 
 <tbody> 
  <tr> 
   <td>QFormLayout::DontWrapRows</td> 
   <td>0</td> 
   <td>Fields are always laid out next to their label. This is the default policy for all styles except Qt Extended styles and&nbsp;<a href="http://qimo601.iteye.com/admin/blogs/1413634/qs60style.html" rel="nofollow">QS60Style</a>.</td> 
  </tr> 
  <tr> 
   <td>QFormLayout::WrapLongRows</td> 
   <td>1</td> 
   <td>Labels are given enough horizontal space to fit the widest label, and the rest of the space is given to the fields. If the minimum size of a field pair is wider than the available space, the field is wrapped to the next line. This is the default policy for Qt Extended styles and and<a href="http://qimo601.iteye.com/admin/blogs/1413634/qs60style.html" rel="nofollow">QS60Style</a>.</td> 
  </tr> 
  <tr> 
   <td>QFormLayout::WrapAllRows</td> 
   <td>2</td> 
   <td>Fields are always laid out below their label.</td> 
  </tr> 
 </tbody> 
</table>

[https_blog.csdn.net_u013928315_article_details_78123573]: https://blog.csdn.net/u013928315/article/details/78123573
[a41a648f9e0c85553c25f53562c3fab2.png]: /images/20221022/6880e605bc554efdac1c55ed83486f51.png
[6309abea4a47c8e8fe291da45b66c17e.png]: /images/20221022/ad1acc4236e84773a3fbebac89f26fbc.png
[5cf278eacb6d6b916f9d2a8906cbe561.png]: /images/20221022/838b345560d5425fa75ba152abacb1f8.png