[Flutter] Flutter implements automatic text wrapping to solve the problem of long text overflow

I. Introduction

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In Flutter development, we often encounter situations where we need to display long text. If the text is too long and exceeds the display range, there will be an overflow problem. To solve this problem, Flutter provides the automatic line wrapping function of the Text component. This article will introduce in detail how to use Flutter's Text component to implement automatic line wrapping to solve the problem of overflowing long text.

Highlights of this article include:

• Introduction to the basic usage and properties of the Flutter Text component
• The importance and implementation of automatic line wrapping in Flutter Text
• The method of realizing automatic line wrapping of Text in complex layout and dynamic data

The version of Flutter used in this article is 3.10.0, and the version of Dart SDK is 3.0.0. Please make sure your development environment meets these version requirements.

2. Introduction to Flutter Text Components

The Text component is one of the most basic components in Flutter, which is used to display simple, consistent text in the application. The basic use of the Text component is very simple, you only need to pass in the text to be displayed as a parameter. For example:

Text('Hello, Flutter!')

This line of code will display a line of "Hello, Flutter!" text in the app.

The Text component has many properties that we can use to control how the text is displayed. For example, we can set the style of the text through the style attribute, such as font, color, size, etc. For example:

Text(
  'Hello, Flutter!',
  style: TextStyle(
    fontSize: 24,
    color: Colors.blue,
  ),
)

This line of code will display a line of blue "Hello, Flutter!" text with a size of 24 pixels.

3. The importance of automatic line wrapping in Flutter Text

When developing Flutter applications, we often encounter situations where we need to display long text. If the text is too long and exceeds the display range, there will be an overflow problem. This not only affects the aesthetics of the application, but may also prevent the user from obtaining complete information. Therefore, it is very important to realize the automatic line-wrapping function of the Text component.

For example, we may need to display a long piece of text in a small container. Without word wrap, the text overflows the container, like this:

Container(
  width: 100,
  child: Text('这是一段非常非常非常非常非常非常非常非常非常非常长的文本'),
)

To solve this problem, we can use the automatic line wrapping function of the Text component.

4. Implementation of automatic line wrapping in Flutter Text

In Flutter, we can implement automatic line wrapping through maxLinesthe and properties of the Text component.overflow

maxLinesProperty is used to set the maximum number of lines of text. If the text exceeds the number of lines maxLines, overflowoverflowing text is handled according to the property.

overflowAttribute is used to set how to handle overflowing text. It has several options including TextOverflow.clip, TextOverflow.fade, TextOverflow.ellipsisand TextOverflow.visible. Among them, TextOverflow.clipthe overflowing text will be cut, TextOverflow.fadethe overflowing text will gradually fade, TextOverflow.ellipsisthe overflowing text will be indicated by an ellipsis, and TextOverflow.visiblethe overflowing text will be visible.

Here's a code example that uses maxLinesand overflowto implement word wrap:

Container(
  width: 100,
  child: Text(
    '这是一段非常非常非常非常非常非常非常非常非常非常长的文本',
    maxLines: 2,
    overflow: TextOverflow.ellipsis,
  ),
)

This code will make the text display up to two lines, if the number of lines of text exceeds two lines, the overflow part will be indicated by ellipsis.

Ok, let's move on to the next two chapters.

---

5. Advanced application of automatic line wrapping in Flutter Text

In the previous section, we introduced how to implement automatic line wrapping of the Text component in a simple case. However, in actual development, we may encounter more complicated situations. For example, we may need to display long text in a complex layout, or need to display dynamically fetched long text. In these cases, we can also use maxLinesthe and overflowproperties of the Text component to achieve automatic line wrapping.

1. Implement automatic text wrapping in complex layouts

In complex layouts, we may need to display long text between multiple components. For example, we may need to display an Icon component and a long text inside a Row component. In this case, we can use the Expanded component to ensure that the Text component gets enough space to display the text.

Row(
  children: [
    Icon(Icons.info),
    Expanded(
      child: Text(
        '这是一段非常非常非常非常非常非常非常非常非常非常长的文本',
        maxLines: 2,
        overflow: TextOverflow.ellipsis,
      ),
    ),
  ],
)

This code will display an Icon component and a long text inside a Row component. Since we used the Expanded component, the Text component was able to take the remaining space of the Row component to display the text. If the number of lines of text exceeds two, the overflow will be indicated by an ellipsis.

2. Realize automatic line wrapping of Text in dynamic data

When developing Flutter apps, we often need to display dynamically fetched data. For example, we may need to fetch data from a Web API and then display this data in the application. In this case, we can also use maxLinesthe and overflowproperties of the Text component to achieve automatic line wrapping.

FutureBuilder<String>(
  future: fetchLongTextFromApi(), // 假设这是一个从 API 获取长文本的函数
  builder: (BuildContext context, AsyncSnapshot<String> snapshot) {
    
    
    if (snapshot.hasData) {
    
    
      return Text(
        snapshot.data,
        maxLines: 2,
        overflow: TextOverflow.ellipsis,
      );
    } else {
    
    
      return CircularProgressIndicator();
    }
  },
)

This code will fetch long text from a web API and display this text in the application. If the number of lines of text exceeds two, the overflow will be indicated by an ellipsis.

6. Summary

In this article, we detailed how to use Flutter's Text component to implement automatic line wrapping to solve the problem of overflowing long text. We first introduced the basic use and properties of the Text component, and then introduced how to use maxLinesand overflowproperties to achieve automatic line wrapping. Finally, we covered how to implement word wrap in complex layouts and dynamic data.

I hope this article can help you better deal with the display of long text when developing Flutter applications. If you have any questions or suggestions, please leave a message in the comment area.

This is the blog published by Xiaoyu Youth on CSDN in 2023. Due to the rampant copyright infringement of the collection station, if you do not see this article on CSDN, please contact me through CSDN, thank you for your support~

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