Provides attached properties for items pushed onto a GridLayout , RowLayout or ColumnLayout . 更多...
| 导入语句： | import QtQuick.Layouts 1.3 |
An object of type Layout is attached to children of the layout to provide layout specific information about the item. The properties of the attached object influence how the layout will arrange the items.
For instance, you can specify minimumWidth , preferredWidth ，和 maximumWidth if the default values are not satisfactory.
When a layout is resized, items may grow or shrink. Due to this, items have a minimum size , preferred size 和 maximum size .
If minimum size has not been explicitly specified on an item, the size is set to
0
. If maximum size has not been explicitly specified on an item, the size is set to
Number.POSITIVE_INFINITY
.
For layouts, the implicit minimum and maximum sizes depend on the content of the layouts.
fillWidth
and
fillHeight
properties can either be
true
or
false
. If they are
false
, the item's size will be fixed to its preferred size. Otherwise, it will grow or shrink between its minimum and maximum size as the layout is resized.
注意： It is not recommended to have bindings to the x, y, width, or height properties of items in a layout, since this would conflict with the goals of Layout, and can also cause binding loops.
另请参阅 GridLayout , RowLayout ，和 ColumnLayout .
|
Layout.alignment : Qt . Alignment |
This property allows you to specify the alignment of an item within the cell(s) it occupies.
默认值为
0
, which means it will be
Qt.AlignVCenter | Qt.AlignLeft
. These defaults also apply if only a horizontal or vertical flag is specified: if only a horizontal flag is specified, the default vertical flag will be
Qt.AlignVCenter
, and if only a vertical flag is specified, the default horizontal flag will be
Qt.AlignLeft
.
A valid alignment is a combination of the following flags:
Specifies the bottom margin outside of an item. If the value is not set, it will use the value from margins .
This QML property was introduced in QtQuick.Layouts 1.2.
另请参阅 margins .
This property allows you to specify the column position of an item in a GridLayout .
If both row and this property are not set, it is up to the layout to assign a cell to the item.
默认值为
0
.
另请参阅 row and columnSpan .
This property allows you to specify the column span of an item in a GridLayout .
默认值为
1
.
若此特性为
true
, the item will be as tall as possible while respecting the given constraints. If the property is
false
, the item will have a fixed height set to the preferred height. The default is
false
, except for layouts themselves, which default to
true
.
另请参阅 fillWidth .
若此特性为
true
, the item will be as wide as possible while respecting the given constraints. If the property is
false
, the item will have a fixed width set to the preferred width. The default is
false
, except for layouts themselves, which default to
true
.
另请参阅 fillHeight .
Specifies the left margin outside of an item. If the value is not set, it will use the value from margins .
This QML property was introduced in QtQuick.Layouts 1.2.
另请参阅 margins .
Sets the margins outside of an item to all have the same value. The item itself does not evaluate its own margins. It is the parent's responsibility to decide if it wants to evaluate the margins.
Specifically, margins are only evaluated by ColumnLayout , RowLayout , GridLayout , and other layout-like containers, such as SplitView , where the effective cell size of an item will be increased as the margins are increased.
Therefore, if an item with margins is a child of another
Item
, its position, size and implicit size will remain unchanged.
Combining margins with alignment will align the item
包括
its margins. For instance, a vertically-centered Item with a top margin of
1
and a bottom margin of
9
will cause the Items effective alignment within the cell to be 4 pixels above the center.
默认值为
0
.
This QML property was introduced in QtQuick.Layouts 1.2.
另请参阅 leftMargin , topMargin , rightMargin ，和 bottomMargin .
The default value is the item's implicit maximum height.
If the item is a layout, the implicit maximum height will be the maximum height the layout can have without any of its items growing beyond their maximum height. The implicit maximum height for any other item is
Number.POSITIVE_INFINITY
.
Setting this value to
-1
will reset the height back to its implicit maximum height.
另请参阅 minimumHeight and preferredHeight .
This property holds the maximum width of an item in a layout. The default value is the item's implicit maximum width.
If the item is a layout, the implicit maximum width will be the maximum width the layout can have without any of its items growing beyond their maximum width. The implicit maximum width for any other item is
Number.POSITIVE_INFINITY
.
Setting this value to
-1
will reset the width back to its implicit maximum width.
另请参阅 minimumWidth and preferredWidth .
This property holds the minimum height of an item in a layout. The default value is the item's implicit minimum height.
If the item is a layout, the implicit minimum height will be the minimum height the layout can have without any of its items shrinking below their minimum height. The implicit minimum height for any other item is
0
.
Setting this value to -1 will reset the height back to its implicit minimum height.
另请参阅 preferredHeight and maximumHeight .
This property holds the minimum width of an item in a layout. The default value is the item's implicit minimum width.
If the item is a layout, the implicit minimum width will be the minimum width the layout can have without any of its items shrinking below their minimum width. The implicit minimum width for any other item is
0
.
Setting this value to -1 will reset the width back to its implicit minimum width.
另请参阅 preferredWidth and maximumWidth .
This property holds the preferred height of an item in a layout. If the preferred height is
-1
it will be ignored, and the layout will use
implicitHeight
instead. The default is
-1
.
另请参阅 minimumHeight and maximumHeight .
This property holds the preferred width of an item in a layout. If the preferred width is
-1
it will be ignored, and the layout will use
implicitWidth
instead. The default is
-1
.
另请参阅 minimumWidth and maximumWidth .
Specifies the right margin outside of an item. If the value is not set, it will use the value from margins .
This QML property was introduced in QtQuick.Layouts 1.2.
另请参阅 margins .
This property allows you to specify the row position of an item in a GridLayout .
If both column and this property are not set, it is up to the layout to assign a cell to the item.
默认值为
0
.
This property allows you to specify the row span of an item in a GridLayout .
默认值为
1
.
另请参阅 columnSpan and row .
Specifies the top margin outside of an item. If the value is not set, it will use the value from margins .
This QML property was introduced in QtQuick.Layouts 1.2.
另请参阅 margins .
