OnScanResult Zxing 后 Xamarin 数据网格不显示答案

【问题标题】：Xamarin datagrid not show up after OnScanResult ZxingOnScanResult Zxing 后 Xamarin 数据网格不显示
【发布时间】：2020-09-03 00:59:27
【问题描述】：

我可以在扫描条形码后获取数据表，但是当我将它绑定到 sfDatagrid 时它不显示。我究竟做错了什么。我想我打电话给 vm.TimSPOnKho.Execute(null);在 .cs 中不正确
代码 xaml 和 .cs

<ContentPage.BindingContext>
        <vm:vmBanHang_get_TTSanPham_ScanCode />
    </ContentPage.BindingContext>
    <StackLayout>
        <Grid VerticalOptions="CenterAndExpand"
                  HorizontalOptions="CenterAndExpand">
            <zxing:ZXingScannerView x:Name="scanView"
                                        OnScanResult="scanView_OnScanResult"
                                        IsScanning="True"
                                        WidthRequest="200"
                                        HeightRequest="300"
                                        VerticalOptions="CenterAndExpand"
                                        HorizontalOptions="CenterAndExpand"/>
            <zxing:ZXingDefaultOverlay TopText="Align the barcode within the frame"/>
        </Grid>
        <datagrid:SfDataGrid HorizontalOptions="Center" x:Name="datagrid"
                                 AllowTriStateSorting="True" 
                                 ColumnSizer="Star"
                                 ItemsSource="{Binding DataTableCollection}">
        </datagrid:SfDataGrid>
    </StackLayout>

这是我的 xaml 文件

private void scanView_OnScanResult(Result result)
    {
        Device.BeginInvokeOnMainThread(async () =>
        {
            await DisplayAlert("Scanned result", "The barcode's text is " + result.Text + ". The barcode's format is " + result.BarcodeFormat, "OK");
            var vm = new vmBanHang_get_TTSanPham_ScanCode();
            vm.MaSanPham = result.Text;
            vm.IDCuaHang = 1;
            vm.TimSPTonKho.Execute(null);


        });

    }

我的 ViewModel.cs

class vmBanHang_get_TTSanPham_ScanCode : INotifyPropertyChanged
{
    private ApiServices _apiServices = new ApiServices();
    public int IDCuaHang { get; set; }
    public string MaSanPham { get; set; }

    public vmBanHang_get_TTSanPham_ScanCode()
    {
        DataTableCollection = _DataTableCollection;
    }
    public DataTable DataTableCollection
    {
        get { return _DataTableCollection; }
        set
        {
            _DataTableCollection = value;
            OnPropertyChanged();
        }
    }

    public DataTable _DataTableCollection;


    public ICommand TimSPTonKho
    {
        get
        {
            return new Command(async () =>
            {
                if (!string.IsNullOrEmpty(MaSanPham))
                {
                    DataTableCollection = await _apiServices.get_TTSanPham_ScanCode(IDCuaHang, MaSanPham, Settings.Accesstoken);
                }

            });
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }
}

2。我的第二个问题，如何获取 Datagrid 发送到 Datatable 的所有值？我必须在 xaml.cs 或 viewmodel 中实现它吗？感谢帮助

【问题讨论】：

标签： xamarin.forms zxing zxing.net

【解决方案1】：

我找到了解决方案。直接从 xaml.cs 绑定

datagrid.ItemsSource = await _apiServices.get_TTSanPham_ScanCode(1, result.Text, Settings.Accesstoken);

而不是在 Viewmodel 中调用 Icommand

public ICommand TimSPTonKho
{
    get
    {
        return new Command(async () =>
        {
            if (!string.IsNullOrEmpty(MaSanPham))
            {
                DataTableCollection = await _apiServices.get_TTSanPham_ScanCode(IDCuaHang, MaSanPham, Settings.Accesstoken);
            }

        });
    }
}

【讨论】：