我在页面上的 AppShell 中使用了 ZXing Nuget 包。它在 AppShell 之外运行良好,但是当我将它添加到 appshell 时。访问页面时收到此错误消息。
xamarin 对象引用未设置为 Zxing.Net.Mobile.Forms.iOS.ZXingScannerView Renderer.LayoutSubviews 处的对象实例
这只发生在 iOS 项目中。
这是扫描仪视图的 XAML 部分。
<StackLayout FlexLayout.Grow="1"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand">
<RelativeLayout x:Name="ZXingScannerViewRelativeLayout"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand"
FlexLayout.AlignSelf="Center">
<zxing:ZXingScannerView x:Name="ZXingScannerView1"
IsScanning="{Binding IsScanning}"
ScanResultCommand="{Binding ScanResultCommand}"
HorizontalOptions="FillAndExpand"
VerticalOptions="FillAndExpand"
AutomationId = "zxingScannerView"
IsAnalyzing="{Binding IsAnalyzing}"
Result="{Binding ScannedResult, Mode=TwoWay}"
IsTorchOn="{Binding IsTorchOn}"
IsVisible="{Binding ScannerViewIsVisible}"
RelativeLayout.WidthConstraint="{ConstraintExpression Type=RelativeToParent,Property=Width}"
RelativeLayout.HeightConstraint="{ConstraintExpression Type=RelativeToParent,Property=Height}">
</zxing:ZXingScannerView>
</RelativeLayout>
</StackLayout>
有任何想法吗?