c# - 将项目添加到 Azure 简易表时，未将 UWP 对象引用设置为对象的实例

Question

我有一个弹出窗口，它接收用户的输入，然后将其发送到模型，然后将其发布到 azure 的简单表。当我构建项目时，一切都运行良好，直到我点击提交按钮，然后应用程序崩溃，并且我得到空异常对象引用未设置为对象的实例。

用于输入的 XAML:

<Popup x:Name="ppup" IsOpen="False" IsLightDismissEnabled="True"  
 Width="320" HorizontalAlignment="Left">
        <Popup.ChildTransitions>
            <TransitionCollection>
                <!--<EdgeUIThemeTransition Edge="Left" />-->
                <PaneThemeTransition Edge="Left" />
            </TransitionCollection>
        </Popup.ChildTransitions>
        <Grid Width="380" Height="{Binding ElementName=flyoutPane, Path=Height}"  Background="{ThemeResource FlyoutBackgroundThemeBrush}" >
            <StackPanel HorizontalAlignment="Center" VerticalAlignment="Center" Margin="10,10,10,10" >
                <TextBlock Name="NameText" Text="Enter Name:"/>
                <TextBox  Name="NameBox" Width="200" Height="50"/>
                <TextBlock Name="SetsText" Text="Enter Sets:"/>
                <TextBox  Name="SetsBox" Width="200" Height="50"/>
                <TextBlock Name="TimeText" Text="Enter Time to complete:"/>
                <TextBox Name="TimeBox" Width="200" Height="50"/>
                <Button Name="SubmitBtn" Height="30" Width="100" Content="Submit" Click="SubmitBtn_Click"/>
            </StackPanel>
        </Grid>
    </Popup>

C# 用于处理输入并将其传递给模型:

CombatTableView ctv = new CombatTableView();

private async void SubmitBtn_Click(object sender, RoutedEventArgs e)
    {
        DrillItem drillItem = new DrillItem();
        String Name = NameBox.Text;
        int Sets = Int32.Parse(SetsBox.Text);
        int Time = Int32.Parse(TimeBox.Text);
        await ctv.combatDrillsTable.AddDrill(drillItem, Name, Sets, Time, parameters);
        ppup.IsOpen = false;
        var dialog = new MessageDialog("Your message here");
        await dialog.ShowAsync();
    }

查看模型:

 class CombatTableView
{
    public CombatDrillsTable combatDrillsTable { get; set; }

    public CombatTableView()
    {
        this.combatDrillsTable = new CombatDrillsTable();
    }
}

与数据库交互的模型:

public async Task AddDrill(DrillItem drillItem, String n, int s, int t, string sty)
    {
        drillItem.Name = n;
        drillItem.Sets = s;
        drillItem.SetTime = t;
        drillItem.Style = sty;

        await App.MobileService.GetTable<DrillItem>().InsertAsync(drillItem);
        drills.Add(drillItem);
    }

Answer 1

就我而言，问题是由于复选框意外绑定(bind)到事件而不是属性造成的:

<CheckBox x:Name="chkIsActive" Checked="{Binding IsActive}" />

而不是

<CheckBox x:Name="chkIsActive" IsChecked="{Binding IsActive}" />