我们可以检查设备是智能手机还是平板电脑吗？

Question

我实际上是想弄清楚该应用程序是在我的flutter应用程序中是在智能手机还是平板电脑上运行，但包装device_info只能显示有关设备的信息，而不能告知该设备是智能手机还是平板电脑。有没有一种方法可以通过检查设备的大小来做到这一点。

非常感谢Mahi

Answer 1

如果您无权访问 BuildContext，则可以使用它。我从sdk/flutter/packages/flutter/lib/src/widgets/app.dart:1252.

  String getDeviceType() {
    final data = MediaQueryData.fromWindow(WidgetsBinding.instance.window);
    return data.size.shortestSide < 600 ? 'phone' :'tablet';
  }

Answer 2

其中一种方法是计算屏幕分辨率的对角线。

import 'package:flutter/widgets.dart';
import 'dart:math';

class TabletDetector {

  // iPhone 6S 
  // |_ [portrait]
  //    |_ size: 375.0x667.0, pixelRatio: 2.0, pixels: 750.0x1334.0
  //       |_ diagonal: 765.1888655750291
  // |_ [horizontal]
  //    |_ size: 667.0x375.0, pixelRatio: 2.0, pixels: 1334.0x750.0
  //       |_ diagonal: 765.1888655750291

  // iPhone X 
  // |_ [portrait]
  //    |_ size: 375.0x812.0, pixelRatio: 3.0, pixels: 1125.0x2436.0
  //       |_ diagonal: 894.4098613052072
  // |_ [horizontal]
  //    |_ size: 812.0x375.0, pixelRatio: 3.0, pixels: 2436.0x1125.0
  //       |_ diagonal: 894.4098613052072

  // iPhone XS Max 
  // |_ [portrait]
  //    |_ size: 414.0x896.0, pixelRatio: 3.0, pixels: 1242.0x2688.0
  //       |_ diagonal: 987.0217829409845
  // |_ [horizontal]
  //    |_ size: 896.0x414.0, pixelRatio: 3.0, pixels: 2688.0x1242.0
  //       |_ diagonal: 987.0217829409845

  // iPad Pro (9.7-inch) 
  // |_ [portrait]
  //    |_ size: 768.0x1024.0, pixelRatio: 2.0, pixels: 1536.0x2048.0
  //       |_ diagonal: 1280.0
  // |_ [horizontal]
  //    |_ size: 1024.0x768.0, pixelRatio: 2.0, pixels: 2048.0x1536.0
  //       |_ diagonal: 1280.0

  // iPad Pro (10.5-inch) 
  // |_ [portrait]
  //    |_ size: 834.0x1112.0, pixelRatio: 2.0, pixels: 1668.0x2224.0
  //       |_ diagonal: 1390.0
  // |_ [horizontal]
  //    |_ size: 1112.0x834.0, pixelRatio: 2.0, pixels: 2224.0x1668.0
  //       |_ diagonal: 1390.0

  // iPad Pro (12.9-inch) 
  // |_ [portrait]
  //    |_ size: 1024.0x1366.0, pixelRatio: 2.0, pixels: 2048.0x2732.0
  //       |_ diagonal: 1707.2000468603555
  // |_ [horizontal]
  //    |_ size: 1366.0x1024.0, pixelRatio: 2.0, pixels: 2732.0x2048.0
  //       |_ diagonal: 1707.2000468603555

  static bool isTablet(MediaQueryData query) {
    var size = query.size;
    var diagonal = sqrt(
      (size.width * size.width) + 
      (size.height * size.height)
    );

    /*
    print(
      'size: ${size.width}x${size.height}\n'
      'pixelRatio: ${query.devicePixelRatio}\n'
      'pixels: ${size.width * query.devicePixelRatio}x${size.height * query.devicePixelRatio}\n'
      'diagonal: $diagonal'
    );
    */

    var isTablet = diagonal > 1100.0;
    return isTablet;
  }
}

Answer 3

尽管 iOS 在手机和平​​板电脑之间有明显的区别，但这在 Android 中不会发生。您需要根据屏幕宽度进行选择。

查看本文以查看有关如何区分的示例：https : //flutter.rocks/2018/01/28/implementing-adaptive-master-detail-layouts/

Answer 4

对于 Android，正如 @Chandler 所说，您应该检查屏幕的最小尺寸，但对于 iOS，您可以使用device_info包以 100% 的准确度识别它是否是 iPad：

加入pubspec.yaml：

device_info: ^0.4.2+4

  static Future<bool> isTablet(BuildContext context) async {

    if (Platform.isIOS) {
      DeviceInfoPlugin deviceInfo = DeviceInfoPlugin();
      IosDeviceInfo iosInfo = await deviceInfo.iosInfo;

      return iosInfo.model.toLowerCase() == "ipad";
    } else {
      // The equivalent of the "smallestWidth" qualifier on Android.
      var shortestSide = MediaQuery.of(context).size.shortestSide;

      // Determine if we should use mobile layout or not, 600 here is
      // a common breakpoint for a typical 7-inch tablet.
      return shortestSide > 600;
    }
  }

Answer 5

2023 年，Dart 3 解决方案的灵感来自 @bakua 的答案，以及这个答案

bool get isTablet {
  final firstView = WidgetsBinding.instance.platformDispatcher.views.first;
  final logicalShortestSide = firstView.physicalSize.shortestSide / firstView.devicePixelRatio;
  return logicalShortestSide > 600;
}

Answer 6

// The equivalent of the "smallestWidth" qualifier on Android.
var shortestSide = MediaQuery.of(context).size.shortestSide;

// Determine if we should use mobile layout or not, 600 here is
// a common breakpoint for a typical 7-inch tablet.
final bool useMobileLayout = shortestSide < 600;

复制自https://flutter.rocks/2018/01/28/implementing-adaptive-master-detail-layouts/

谢谢@Sergi

Answer 7

这里与其他 aswers 相同，但返回 anenum而不是 abool或 a String。因为它更封闭，所以使用起来更容易。

import 'package:flutter/widgets.dart';

enum DeviceType { Phone, Tablet }

DeviceType getDeviceType() {
  final data = MediaQueryData.fromWindow(WidgetsBinding.instance.window);
  return data.size.shortestSide < 550 ? DeviceType.Phone : DeviceType.Tablet;
}

感谢@Chandler 和@bakua 的启发:·)