ZXing.Net.Mobile視圖不會爲Xamarin中的UWP拉伸。表格

Question

我在Xamarin.Forms應用程序中使用了ZXing.Net.Mobile ZXingScannerView。我使用Android API 21+和Windows Mobile 10對其進行測試。在Android中，相機流完美地擴展到掃描儀視圖的邊界，而UWP則不適用。無論是模擬器的大小還是分辨率。我「以前也嘗試過一個真正的Windows Phone設備，仍然出現問題

我放在ZXingScannerView在類似這樣的內容頁：

<ContentPage.Content> 
    <StackLayout Spacing="20" Padding="15"> 
     ... 
     <Grid 
      HorizontalOptions="FillAndExpand" 
      VerticalOptions="FillAndExpand"> 
      <zxing:ZXingScannerView 
       x:Name="zxing" 
       Result="{Binding ScannerResult, Mode=TwoWay}" 
       IsScanning="{Binding ScannerScanning}" 
       IsVisible="{Binding ScannerVisible}" 
       IsAnalyzing="{Binding ScannerAnalyzing}" 
       ScanResultCommand="{Binding ScannedCommand}"/> 
      <v:MainPageZXingOverlayView /> 
     </Grid> 
     ... 
    </StackLayout> 
</ContentPage.Content> 

而且我已經注意到，view .xaml有捕獲元件設置爲伸展= 「填充」

<CaptureElement 
     Grid.Row="0" 
     Grid.Column="0" 
     x:Name="captureElement" 
     Stretch="Fill" /> 

也view .cs

// *after* the preview is setup, set this so that the UI layout happens 
// otherwise the preview gets stuck in a funny place on screen 
captureElement.Stretch = Stretch.UniformToFill; 

任何人遇到同樣的問題或有解決辦法嗎？

Answer 1

儘管在Android的相機流膨脹以完美掃描器視圖的邊界，這是不適合UWP真。無論是模擬器的大小還是分辨率。我「以前也嘗試過一個真正的Windows Phone設備，仍然會出現問題。

的預覽分辨率基於攝像頭的分辨率設置時，相機開始掃描。

爲了您的要求，您可以擴展預覽通過自定義相機分辨率的界限，請參考下面的代碼：

private async void Button_Clicked(object sender, EventArgs e) 
{     
    var options = new ZXing.Mobile.MobileBarcodeScanningOptions 
    { 
     CameraResolutionSelector = HandleCameraResolutionSelectorDelegate 
    }; 
    var scanner = new ZXing.Mobile.MobileBarcodeScanner(); 
    scanner.AutoFocus(); 
    var result = await scanner.Scan(options); 
    if (result != null) 
     System.Diagnostics.Debug.WriteLine("Scanned Barcode: " + result.Text); 
} 
CameraResolution HandleCameraResolutionSelectorDelegate(List<CameraResolution> availableResolutions) 
{ 
    //Don't know if this will ever be null or empty 
    if (availableResolutions == null || availableResolutions.Count < 1) 
     return new CameraResolution() { Width = 800, Height = 600 }; 

    //Debugging revealed that the last element in the list 
    //expresses the highest resolution. This could probably be more thorough. 
    return availableResolutions[availableResolutions.Count - 1]; 
} 

UPD吃了

請注意，我使用ZXingScannerView本身，但不是內置的包裝。我已經更新了我的問題，以便更清楚。

如果您使用ZXingScannerView，您還可以在後面的代碼中修改ZXingScannerView選項。

public MainPage() 
{ 
    InitializeComponent(); 
    var options = new ZXing.Mobile.MobileBarcodeScanningOptions 
    { 
     CameraResolutionSelector = HandleCameraResolutionSelectorDelegate 
    }; 
    zxing.Options = options; 
} 
CameraResolution HandleCameraResolutionSelectorDelegate(List<CameraResolution> availableResolutions) 
{ 
    //Don't know if this will ever be null or empty 
    if (availableResolutions == null || availableResolutions.Count < 1) 
     return new CameraResolution() { Width = 800, Height = 600 }; 

    //Debugging revealed that the last element in the list 
    //expresses the highest resolution. This could probably be more thorough. 
    return availableResolutions[availableResolutions.Count - 1]; 
}