Flutter - How to display markdown text in sliver

Question

I'm trying to run Markdown widget (package: flutter_markdown 0.2.0) inside a SliverList but I have some issues.

Ideally I would like to execute a Markdown widget inside an ExpandTile widget inside a Sliver, but for now I just want to solve the problem of Markdown child of a Sliver.

The code I'm posting give me issues:

• I see correctly the markdown text but the app is freezed (I can't scroll, I can't do nothing). I have this behaviour when I use the widget MarkdownBody

• I see an error message when I use the widget Markdown:

I/flutter (31761): ══╡ EXCEPTION CAUGHT BY RENDERING LIBRARY ╞═════════════════════════════════════════════════════════
I/flutter (31761): The following assertion was thrown during performResize():
I/flutter (31761): Vertical viewport was given unbounded height.
I/flutter (31761): Viewports expand in the scrolling direction to fill their container.In this case, a vertical
I/flutter (31761): viewport was given an unlimited amount of vertical space in which to expand. This situation
I/flutter (31761): typically happens when a scrollable widget is nested inside another scrollable widget.
I/flutter (31761): If this widget is always nested in a scrollable widget there is no need to use a viewport because
I/flutter (31761): there will always be enough vertical space for the children. In this case, consider using a Column
I/flutter (31761): instead. Otherwise, consider using the "shrinkWrap" property (or a ShrinkWrappingViewport) to size
I/flutter (31761): the height of the viewport to the sum of the heights of its children.
I/flutter (31761):
...

This is the full code of my example:

import 'package:flutter/material.dart';
import 'package:flutter_markdown/flutter_markdown.dart';

const String _markdownData = """# Markdown Example
Markdown allows you to easily include formatted text, images, and even formatted Dart code in your app.

## Styling
Style text as _italic_, __bold__, or `inline code`.

- Use bulleted lists
- To better clarify
- Your points

## Links
You can use [hyperlinks](hyperlink) in markdown

## Images

You can include images:

![Flutter logo](https://flutter.io/images/flutter-mark-square-100.png#100x100)

## Markdown widget

This is an example of how to create your own Markdown widget:

    new Markdown(data: 'Hello _world_!');

## Code blocks
Formatted Dart code looks really pretty too:

void main() {
  runApp(new MaterialApp(
    home: new Scaffold(
      body: new Markdown(data: markdownData)
    )
  ));
}

Enjoy!
""";

void main() {
  runApp(MaterialApp(
      title: "Markdown Demo",
      home: Scaffold(
          appBar: AppBar(title: const Text('Markdown Demo')),
          body: Container(
              child: CustomScrollView(slivers: <Widget>[
            SliverList(
              delegate:
                  SliverChildListDelegate([Markdown(data: _markdownData)]),
            )
          ])))));
}

EDIT: I solved the issue

The problem was in this line of code:

![Flutter logo](https://flutter.io/images/flutter-mark-square-100.png#100x100)

The image don't exist and this freeze the app.

Solution

Use SliverToBoxAdapter instead of SliverList

Comments

[ilBarra]

Works only if I set the height property in the Container widget: void main() { Widget _buildSliverToBoxAdapter(){ return SliverToBoxAdapter( child: Container( height: 400.0, child: Markdown(data: _markdownData) ), ); } runApp(MaterialApp( title: "Markdown Demo", home: Scaffold( body: CustomScrollView( slivers: <Widget>[ _buildSliverToBoxAdapter(), ])))); } This is a problem because the length of the markdown text is dynamic.

[Hassan Saleh]

Try SliverToBoxAdapter inside SliverFillRemaining