What is the difference between gridview.builder and gridview.count in Flutter?
Like any other .builder GridView.builder create Widgets on demand.
Creates a scrollable, 2D array of widgets that are created on demand.
This constructor is appropriate for grid views with a large (or infinite) number of children because the builder is called only for those children that are actually visible.
But GridView.count allows to directly have crossAxisCount that use to count item on single row. Full Grandview will follow this pattern.
Creates a scrollable, 2D array of widgets with a fixed number of tiles in the cross axis.
When you have the large number of widgets, consider using GridView.builder to get better performance. Also, using gridDelegate gives you more controls over UI.
You can explore GridView.
Related
I need a grid that contains children of fixed sizes.
GridView expands its children, which is not what I need. The grid should simply size itself according to it's children by setting the crossAxisCount.
My current solution is to use simple columns and rows, but that's so much boilerplate code for just a common widget.
You will have to do it dynamically, and supply the value of the crossAxisCount dynamically
In a flutter app, what is the difference between a Container inside a Row and a Row inside Container?
In flutter in each time I want to make an app, I took minutes to ask my self
which one should I choose?
In flutter Row and Column provide a way to use the Flex layout system aka FlexBox.
In short Flex is a one-dimensional layout system, where in the children can be aligned on the main-axis or cross-axis, the main axis can be defined as horizontal or vertical.
A Container in Flutter is a general-purpose widget that gives you access to a range of properties like padding, decoration, size etc. A full-list is available at the API Docs
To answer your question,
A Container in a Row is like we said above, a child of a Flex, which means it will respect the properties of alignment set by the parent (MainAxisAlignment/CrossAxisAlignment )
A Row in a Container, is the opposite of that which means that, the Row or Column will respect properties set on the Container that is for example the Decoration or Size properties amongst others.
I want to create a grid with large number of cells. On screen not all cells should be shown, but only some cells at the center of the screen.
Just like the app Desmos.
It should be possible to scroll from any direction in the app.
// THE PROBLEM IS WITH THE NEXT LINE , AS I DON'T THINK I CAN USE double.infinity.toInt() FOR INFINITE //NUMBER OF CELLS. AND EVEN IF IT WORKS HOW CAN I SET THE NUMBER OF CELLS IN A VERTICAL COLUMN TO //INFINITE OR ANY LARGE NUMBER.
GridView.count(crossAxisCount: double.infinity.toInt()),
.....
//Here is the code that will define the 4 Coordinates for each cell.
),
GridView.count creates a scrollable, 2D array of widgets with a fixed number of tiles in the cross axis.
What you need to use is some other GridView constructor like GridView.builder.
https://api.flutter.dev/flutter/widgets/GridView/GridView.builder.html
Creates a scrollable, 2D array of widgets that are created on demand.
This constructor is appropriate for grid views with a large (or
infinite) number of children because the builder is called only for
those children that are actually visible.
I have a ListView with a Column, and inside that Column 2 buttons.
The ListView is stretched to the entire page (it contains more elements)
I want all the buttons inside the Column to stretch to the button with the largest width.
I found a solution on usnig InstrictWidth, but when used inside a Listview I'm getting the error
LayoutBuilder does not support returning intrinsic dimensions.
How can I still achieve what I'm looking for?
Wrap each button with an Expanded widget and then wrap each one of these Expanded widgets with a Row widget
I'm using PyGTK on Windows to develop a small application.
How can I enforce vertical alignment of widgets across containers to achieve something like this?
In the mockup, widgets are in separate frames, but I want to maintain vertical alignment as if they were in the same gtk.Table. If I put them in the same table then I can't put a gtk.Frame around the groups of widgets.
Maybe it's already too late for you, but for other people that find this question. You can create an array of SizeGroup with 8 elements, and add to each element every widget that should go on the same column, this will make the width of each cell on the respective grid to be the same size, if all widgets are added, this will have the side effect of also align them vertically. Just be sure the amount of columns in the grid below is the same as above.
Also, if your labels need some special alignment there is currently a bug that does not let you use halign and valign when using SizeGroup, see https://bugzilla.gnome.org/show_bug.cgi?id=733981 .