我正在使用 ZXing.Net.Mobile 库来扫描二维码。我想将负责扫描的代码放在单独的类中,这样我就可以从中调用一个方法,它会返回结果。像这样的东西:
var scanner = new ZXing.Mobile.MobileBarcodeScanner();
var result = await scanner.Scan();
if (result != null)
Console.WriteLine("Scanned Barcode: " + result.Text);
这是官方存储库中的一个示例,但它不起作用(至少对我而言)。所以我创建了一个类,并将 DID 工作的代码放在其他地方。这是课程代码:
public class QrHandler
{
public ZXingScannerPage scanPage { get; set; }
public string Result { get; set; }
public async Task<string> Scan()
{
var options = new ZXing.Mobile.MobileBarcodeScanningOptions
{
PossibleFormats = new List<ZXing.BarcodeFormat>
{
ZXing.BarcodeFormat.QR_CODE
},
TryHarder = false,
AutoRotate = false,
TryInverted = false,
};
scanPage = new ZXingScannerPage();
scanPage.AutoFocus();
scanPage.OnScanResult += (result) =>
{
scanPage.IsScanning = false;
Device.BeginInvokeOnMainThread(async () =>
{
Application.Current.MainPage.Navigation.PopAsync();
try
{
Result = result.Text;
}
catch (Exception ex)
{
Result = ex.Message;
}
});
};
await Application.Current.MainPage.Navigation.PushAsync(scanPage);
return Result;
}
}
我通过如下方法调用它:
public async Task<string> Validate()
{
string _Result = "OK";
QrHandler q = new QrHandler();
_Result = await q.Scan();
return _Result;
}
问题是 Validate() 在 q.Scan() 返回任何值之前返回 _Result。q.Scan() 完成后不应该触发它吗?