出现键盘时，Flutter小部件将调整大小。如何预防这种情况?

我有一个像这样的扩展小部件列:

 return new Container(
      child: new Column(
        crossAxisAlignment: CrossAxisAlignment.stretch,
        children: <Widget>[
          new Expanded(
            flex: 1,
            child: convertFrom,
          ),
          new Expanded(
            flex: 1,
            child: convertTo,
          ),
          new Expanded(
            flex: 1,
            child: description,
          ),
        ],
      ),
    );

它是这样的:

convertFrom，包括一个TextField。当我点击这个文本框时，Android键盘就会出现在屏幕上。这会改变屏幕大小，所以小部件会像这样调整大小:

有没有办法让键盘“覆盖”屏幕，使我的列不调整大小?如果我不使用Expanded widgets，并为每个widget硬编码一个高度，这些widget就不会调整大小，但是当键盘出现时，我会得到一个黑黄条纹错误(因为没有足够的空间)。这也不是对所有屏幕尺寸都灵活。

我不确定这是android特有的还是flutter特有的。

当前回答

特点:

打开键盘时，背景图像不会调整大小能够滚动隐藏在键盘后面的元素

import 'package:flutter/material.dart';

SizedBox addPaddingWhenKeyboardAppears() {
  final viewInsets = EdgeInsets.fromWindowPadding(
    WidgetsBinding.instance!.window.viewInsets,
    WidgetsBinding.instance!.window.devicePixelRatio,
  );

  final bottomOffset = viewInsets.bottom;
  const hiddenKeyboard = 0.0; // Always 0 if keyboard is not opened
  final isNeedPadding = bottomOffset != hiddenKeyboard;

  return SizedBox(height: isNeedPadding ? bottomOffset : hiddenKeyboard);
}

/// The size of the screen.
class ScreenSizeService {
  final BuildContext context;

  const ScreenSizeService(
    this.context,
  );

  Size get size => MediaQuery.of(context).size;
  double get height => size.height;
  double get width => size.width;
}

class LoginPage extends StatelessWidget {
  final _imageUrl =
      'https://images.unsplash.com/photo-1631823460501-e0c045fa716f?ixid=MnwxMjA3fDB8MHxlZGl0b3JpYWwtZmVlZHwyNHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=500&q=60';

  const LoginPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final screenWidth = ScreenSizeService(context).width;
    final screenHeight = ScreenSizeService(context).height;

    return Scaffold(
      resizeToAvoidBottomInset: false,
      body: Container(
        decoration: BoxDecoration(
          image: DecorationImage(
            image: NetworkImage(_imageUrl),
            fit: BoxFit.cover,
          ),
        ),
        child: SingleChildScrollView(
          child: ConstrainedBox(
            constraints: BoxConstraints(
              minWidth: screenWidth,
              minHeight: screenHeight,
            ),
            child: Column(
              children: [
                ...List.generate(6, (index) {
                  return Column(
                    children: [
                      Container(
                        height: 60,
                        width: double.maxFinite,
                        color: Colors.pink[100],
                        child: Center(child: Text('$index')),
                      ),
                      const SizedBox(height: 40),
                    ],
                  );
                }),
                Container(color: Colors.white, child: const TextField()),
                addPaddingWhenKeyboardAppears(),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

2021-09-18 12:06:02

其他回答

你可以使用

Scaffold(
  resizeToAvoidBottomInset: false, 
  ... 
)

或者可以将小部件打包

SingleChildScrollView

2022-12-30 13:16:13

特点:

打开键盘时，背景图像不会调整大小能够滚动隐藏在键盘后面的元素

import 'package:flutter/material.dart';

SizedBox addPaddingWhenKeyboardAppears() {
  final viewInsets = EdgeInsets.fromWindowPadding(
    WidgetsBinding.instance!.window.viewInsets,
    WidgetsBinding.instance!.window.devicePixelRatio,
  );

  final bottomOffset = viewInsets.bottom;
  const hiddenKeyboard = 0.0; // Always 0 if keyboard is not opened
  final isNeedPadding = bottomOffset != hiddenKeyboard;

  return SizedBox(height: isNeedPadding ? bottomOffset : hiddenKeyboard);
}

/// The size of the screen.
class ScreenSizeService {
  final BuildContext context;

  const ScreenSizeService(
    this.context,
  );

  Size get size => MediaQuery.of(context).size;
  double get height => size.height;
  double get width => size.width;
}

class LoginPage extends StatelessWidget {
  final _imageUrl =
      'https://images.unsplash.com/photo-1631823460501-e0c045fa716f?ixid=MnwxMjA3fDB8MHxlZGl0b3JpYWwtZmVlZHwyNHx8fGVufDB8fHx8&ixlib=rb-1.2.1&auto=format&fit=crop&w=500&q=60';

  const LoginPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final screenWidth = ScreenSizeService(context).width;
    final screenHeight = ScreenSizeService(context).height;

    return Scaffold(
      resizeToAvoidBottomInset: false,
      body: Container(
        decoration: BoxDecoration(
          image: DecorationImage(
            image: NetworkImage(_imageUrl),
            fit: BoxFit.cover,
          ),
        ),
        child: SingleChildScrollView(
          child: ConstrainedBox(
            constraints: BoxConstraints(
              minWidth: screenWidth,
              minHeight: screenHeight,
            ),
            child: Column(
              children: [
                ...List.generate(6, (index) {
                  return Column(
                    children: [
                      Container(
                        height: 60,
                        width: double.maxFinite,
                        color: Colors.pink[100],
                        child: Center(child: Text('$index')),
                      ),
                      const SizedBox(height: 40),
                    ],
                  );
                }),
                Container(color: Colors.white, child: const TextField()),
                addPaddingWhenKeyboardAppears(),
              ],
            ),
          ),
        ),
      ),
    );
  }
}

2021-09-18 12:06:02

更新后的答案

resizeToAvoidBottomPadding现在已弃用。

更新后的解决方案是将resizeToAvoidBottomInset属性设置为false。

原来的答案

在你的Scaffold中，设置resizeToAvoidBottomPadding属性为false。

2017-10-03 18:45:36

根据用例，您还可以考虑使用列表视图。这将确保当没有足够的空间时，内容会滚动。作为一个例子，你可以在图库应用程序中查看文本框演示

2017-10-04 03:10:01

将resizeToAvoidBottomInset的值设置为false对我来说效果很好。

此外，resizeToAvoidBottomPadding对我来说工作得很好。你可以用任何一个。

2021-01-18 18:02:07