ZXing.Net.Maui条码扫描器仅横屏可扫描，竖屏无法识别求助

我正在将现有条码扫描应用升级至.NET Maui，使用ZXing.Net.Maui控件开发。目前遇到问题：竖屏模式下无法扫描条码，但切换到横屏模式后即可正常识别。以下是我的界面布局代码和后台代码，请问遗漏了哪些配置或设置？

界面布局代码 #

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:zxing="clr-namespace:ZXing.Net.Maui.Controls;assembly=ZXing.Net.MAUI.Controls"
             x:Class="Scanner.Scan"
             x:DataType="Line"
             Title="Scan">
    <ScrollView>
        <VerticalStackLayout
            Padding="30,0"
            Spacing="25">
            <Image
                Source="banner2.jpg"
                HeightRequest="75"
                Aspect="AspectFit"/>
            <Line Stroke="Black" X2="{Binding Width, Source={RelativeSource Self}}" HorizontalOptions="Fill" StrokeThickness="2" />
            <zxing:CameraBarcodeReaderView 
                x:Name="barcodeReader"
                WidthRequest="350" 
                HeightRequest="450"
                IsDetecting="True" 
                IsTorchOn="False" 
                BarcodesDetected="OnBarcodesDetected" />
            <Label 
                Text="Ready to scan."
                VerticalOptions="Center" 
                HorizontalOptions="Center" />
            </VerticalStackLayout>
        </ScrollView>
</ContentPage> 

后台代码 #

public partial class Scan : ContentPage
{

    protected override void OnAppearing()
    {
        base.OnAppearing();
    }
    public Scan()
    {
        InitializeComponent();
    }

    protected void OnBarcodesDetected(object? sender, BarcodeDetectionEventArgs e)
    {
        foreach (var barcode in e.Results)
        {
            // Process the scanned barcode data
            //Console.WriteLine($"Barcode Format: {barcode.Format}, Value: {barcode.Value}");
        }
    }
}

问题解决步骤 #

• 移除ScrollView容器
  把CameraBarcodeReaderView放在ScrollView中会导致竖屏时预览区域的触摸和识别逻辑异常，直接用VerticalStackLayout作为根布局：

  <ContentPage ...>
      <VerticalStackLayout
          Padding="30,0"
          Spacing="25">
          <!-- 原有控件 -->
          <zxing:CameraBarcodeReaderView ... />
          <!-- 原有控件 -->
      </VerticalStackLayout>
  </ContentPage>
  

• 取消固定宽高，适配父容器
  固定的WidthRequest和HeightRequest会让竖屏时相机预览被裁剪或拉伸，改为填充父容器并设置合理比例：

  <zxing:CameraBarcodeReaderView 
      x:Name="barcodeReader"
      HorizontalOptions="Fill"
      VerticalOptions="Fill"
      AspectRatio="4:3"
      IsDetecting="True" 
      IsTorchOn="False" 
      BarcodesDetected="OnBarcodesDetected" />
  

• 配置扫描选项适配竖屏
  在OnAppearing中设置自动旋转和扫描区域，确保竖屏时识别逻辑正确：

  protected override void OnAppearing()
  {
      base.OnAppearing();
      barcodeReader.CameraLocation = CameraLocation.Back;
      barcodeReader.Options = new BarcodeReaderOptions
      {
          AutoRotate = true,
          TryHarder = true,
          // 按屏幕尺寸设置扫描区域
          ScanRegion = new Rect(0, 0, DeviceDisplay.Current.MainDisplayInfo.Width, DeviceDisplay.Current.MainDisplayInfo.Height)
      };
  }
  

• 确认权限配置

  • Android：在AndroidManifest.xml中添加相机权限

    <uses-permission android:name="android.permission.CAMERA" />
    

  • iOS：在Info.plist中添加相机权限说明

    <key>NSCameraUsageDescription</key>
    <string>需要使用相机扫描条码</string>
    

内容的提问来源于stack exchange，提问作者Prescott Chartier