If you are looking for an efficient way to display a collection of items in a grid-like layout in your Flutter app, the GridView widget is a popular choice. GridView is a flexible widget in Flutter that allows you to create a grid of items such as images, text, or icons. You can customize the grid's appearance and behavior with GridView Widget properties as well. In this article, we will be discussing how to use GridView Builder in Flutter with code examples.
What is GridView Builder?
GridView builder is a widget that's an extension of the GridView widget in Flutter. GridView Builder is a way of dynamically building a grid with a certain number of items. This builder takes in a list of items, creates cells for each item to be displayed, and then arranges these cells in a grid layout. The advantage of using GridView Builder is that it helps optimize your performance by only rendering the cells that are currently visible, instead of rendering all the items at once, resulting in a smoother and faster performance.
Creating a GridView Builder
To create a GridView Builder, we first need to create a list of items that we want to display in the grid layout. For instance, let’s say we want to display the names of some fruits in the grid layout. We can do this by creating a list of fruit names like so:
List<String> fruits = [
"Apple",
"Banana",
"Cherry",
"Durian",
"Elderberry",
"Fig",
"Grape",
"Honeydew melon"
];
Once we have our list of items, we can create a GridView Builder widget to display these items in a grid layout. The GridView builder can be created using the following code.
GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
),
itemCount: fruits.length,
itemBuilder: (BuildContext context, int index) {
return Container(
child: Center(
child: Text(
fruits[index],
),
),
);
},
),
Breaking down the code above, the first property gridDelegate delegates how the items should be shown in the grid layout. In this example, we use the SliverGridDelegateWithFixedCrossAxisCount to show the items in a grid layout with a specified number of columns. We set the crossAxisCount property to "2" to create a grid with two columns.
The second property itemCount is used to define the total number of items that should be displayed in the grid.
The last property itemBuilder takes in a function that returns the widget to be displayed in each cell of the grid. Here, we use a Container widget with a Text widget inside to display each fruit name.
Customizing GridView Builder
You can also customize the grid layout by changing SliverGridDelegateWithFixedCrossAxisCount properties. For instance, you can adjust the spacing between items by using the mainAxisSpacing and crossAxisSpacing properties. You can also use SliverGridDelegateWithMaxCrossAxisExtent for building a grid with a maximum number of cells and defining the maximum extent of each cell.
Here's an example of customizing the GridView builder using SliverGridDelegateWithMaxCrossAxisExtent.
GridView.builder(
gridDelegate: SliverGridDelegateWithMaxCrossAxisExtent(
maxCrossAxisExtent: 200,
crossAxisSpacing: 20.0,
mainAxisSpacing: 20.0,
),
itemCount: fruits.length,
itemBuilder: (BuildContext context, int index) {
return Container(
decoration: BoxDecoration(
border: Border.all(
color: Colors.black,
),
),
child: Center(
child: Text(
fruits[index],
),
),
);
},
),
In this example, we use the SliverGridDelegateWithMaxCrossAxisExtent instead of FixedCrossAxisCount and set maxCrossAxisExtent to "200". This defines the maximum extent of each cell in the grid. We also set crossAxisSpacing and mainAxisSpacing to "20.0" to set spacing between the cells.
We can also add decoration to each container using a BoxDecoration to add a border around each cell.
Conclusion
Using the GridView Builder in Flutter makes it easy to create a grid layout with the specified items. It provides a flexible and efficient way of displaying a collection of items in a grid-like layout. In this article, we have discussed how to use the GridView Builder in Flutter with code examples. Use these concepts to create an efficient grid layout.
let's dive deeper into the features and properties of the GridView Builder widget in Flutter.
Properties of GridView Builder Widget
-
gridDelegate: This property is used to set the type of layout that should be displayed in the grid. GridDelegate is the base class that's used to define grid layouts.SliverGridDelegateWithFixedCrossAxisCountandSliverGridDelegateWithMaxCrossAxisExtentare the two classes that extend GridDelegate and are commonly used. -
itemCount: This property specifies the number of items in the grid. Generally, theitemCountis taken as the length of the list of items we want to display in the grid layout. -
itemBuilder: This is a builder function that's used to build the individual items in the grid layout. The builder function should accept two arguments, aBuildContextobject and an integer for the current item index, and must return aWidgetto build an item.
Code example for using SliverGridDelegateWithFixedCrossAxisCount:
GridView.builder(
itemCount: itemsList.length,
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 3,
childAspectRatio: 0.7,
crossAxisSpacing: 10,
mainAxisSpacing: 10,
),
itemBuilder: (BuildContext context, int index) {
return Container(
child: Card(
elevation: 3,
child: Column(
children: [
Expanded(
child: Container(
height: 150,
width: double.infinity,
decoration: BoxDecoration(
image: DecorationImage(
image: NetworkImage(
itemsList[index]['icon']
),
fit: BoxFit.cover
),
),
),
),
Padding(
padding: const EdgeInsets.all(10.0),
child: Column(
crossAxisAlignment: CrossAxisAlignment.start,
children: [
Text(
itemsList[index]['name'],
style: TextStyle(
fontSize: 18,
fontWeight: FontWeight.bold
),
),
SizedBox(height: 8,),
Text(
itemsList[index]['description'],
style: TextStyle(
fontSize: 14,
color: Colors.grey
),
),
],
),
),
],
),
),
);
},
)
In the code example above, we have used a practical use case of an embodiment of Gridview Builder. Here we are displaying the items with a fixed 3-column layout. To create a 3-column layout, we set the crossAxisCount property to 3. We have also set childAspectRatio to 0.7, which means that our items will have a width-to-height ratio of 7:10. crossAxisSpacing and mainAxisSpacing are used to define the amount of space between individual items.
Customizing GridView Builder
We can customize the appearance of the GridView Builder using different properties, including:
-
crossAxisCount: This property specifies the number of columns in the grid. -
mainAxisSpacing: This property sets the space between rows in the grid. -
crossAxisSpacing: This property sets the space between columns in the grid. -
childAspectRatio: This property sets the aspect ratio of each child. -
padding: This property sets the padding of the GridView.
Here's an example of customizing the GridView Builder using padding and aspect ratio:
GridView.builder(
padding: EdgeInsets.symmetric(horizontal: 10),
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 3,
childAspectRatio: 3 / 4,
crossAxisSpacing: 5,
mainAxisSpacing: 5,
),
itemCount: itemsList.length,
itemBuilder: (BuildContext context, int index) => Image.network(
itemsList[index]['url'],
fit: BoxFit.cover,
),
),
In the code example above, we have added padding around the GridView using the padding property. The childAspectRatio property has been set to 3/4, which sets the aspect ratio of each widget in the GridView.
Conclusion
The GridView Builder Widget is an important Flutter feature that provides a flexible way to display large amounts of data in a grid-like layout. By using the GridView Builder Widget, developers can create a dynamic and smooth user interface that's responsive, easy to use and efficient. By experimenting with the properties and customizing the GridView Builder Widget, developers can create unique and engaging layouts for their Flutter applications.
Popular questions
- What is the GridView Builder widget in Flutter?
The GridView Builder widget is an extension of the GridView widget that dynamically builds a grid with a certain number of items. This widget is used to display a collection of items in a grid-like layout.
- Can you explain the properties of the GridView Builder widget?
The properties of the GridView Builder widget include:
gridDelegate: This property is used to set the type of layout that should be displayed in the grid.itemCount: This property specifies the number of items in the grid.itemBuilder: This is a builder function that's used to build the individual items in the grid layout.
- What are the benefits of using the GridView Builder widget?
Using the GridView Builder widget in your Flutter app provides a flexible and efficient way to display a collection of items in a grid-like layout. This widget optimizes performance by only rendering the cells that are currently visible, resulting in a smoother and faster performance.
- How can you customize the appearance of the GridView Builder widget?
You can customize the appearance of the GridView Builder widget using different properties, including crossAxisCount, mainAxisSpacing, crossAxisSpacing, childAspectRatio, and padding. These properties can be used to adjust the number of columns, the spacing between columns and rows, the aspect ratio of each child, and the padding around the GridView.
- Can you provide a code example of using the GridView Builder widget in Flutter?
Here's a code example of using the GridView Builder widget in Flutter:
GridView.builder(
gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
crossAxisCount: 2,
),
itemCount: fruits.length,
itemBuilder: (BuildContext context, int index) {
return Container(
child: Center(
child: Text(
fruits[index],
),
),
);
},
),
In this example, we have created a GridView Builder widget to display a collection of fruit names in a grid layout. The gridDelegate property is set to SliverGridDelegateWithFixedCrossAxisCount, and the itemBuilder function builds a container with a centered text widget for each fruit name.
Tag
FlutterGridView
