c# - 初始化组件抛出空引用异常

Question

我在打开新窗口的大型程序中有一个菜单项。没有任何内容传递给它，它加载一个日历、3 个空文本框、3 个标签、2 个按钮和一个空的 Crystal Report Viewer。

当它运行时，用户点击日历，这会自动将所选月份的第一个和最后一个日期插入到两个文本框中。一个按钮使用数据库中的数据加载 CR 报告，另一个按钮打印报告。

这在我的系统上运行良好，但在同事系统上部署时初始化组件抛出空引用异常。我无法在我的系统上重新创建异常。

有人知道我应该从哪里开始吗？

已更新

错误

System.NullReferenceException: Object reference not set to an instance of an object.
   at System.Windows.Baml2006.Baml2006Reader.Process_PropertyWithConverter()
   at System.Windows.Baml2006.Baml2006Reader.Process_OneBamlRecord()
   at System.Windows.Baml2006.Baml2006Reader.Process_BamlRecords()
   at System.Windows.Baml2006.Baml2006Reader.Read()
   at System.Windows.Markup.WpfXamlLoader.TransformNodes(XamlReader xamlReader, XamlObjectWriter xamlWriter, Boolean onlyLoadOneNode, Boolean skipJournaledProperties, Boolean shouldPassLineNumberInfo, IXamlLineInfo xamlLineInfo, IXamlLineInfoConsumer xamlLineInfoConsumer, XamlContextStack`1 stack, IStyleConnector styleConnector)
   at System.Windows.Markup.WpfXamlLoader.Load(XamlReader xamlReader, IXamlObjectWriterFactory writerFactory, Boolean skipJournaledProperties, Object rootObject, XamlObjectWriterSettings settings, Uri baseUri)
   at System.Windows.Markup.WpfXamlLoader.LoadBaml(XamlReader xamlReader, Boolean skipJournaledProperties, Object rootObject, XamlAccessLevel accessLevel, Uri baseUri)
   at System.Windows.Markup.XamlReader.LoadBaml(Stream stream, ParserContext parserContext, Object parent, Boolean closeStream)
   at System.Windows.Application.LoadComponent(Object component, Uri resourceLocator)
   at KeyInScreen.RebatesReports.InitializeComponent()
   at KeyInScreen.RebatesReports..ctor()
   at KeyInScreen.Menu.FertiliserRebate_Click(Object sender, RoutedEventArgs e)

XAML 代码

<Window x:Class="KeyInScreen.RebatesReports"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Fertiliser Rebates" WindowState="Maximized" 
    xmlns:my="clr-namespace:SAPBusinessObjects.WPF.Viewer;assembly=SAPBusinessObjects.WPF.Viewer" 
    mc:Ignorable="d" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" Height="700" 
    Width="1350">
<Window.Resources>
    <Style TargetType="{x:Type Label}">
        <Setter Property="FontSize" Value="14" />
    </Style>
    <Style TargetType="{x:Type Button}">
        <Setter Property="FontSize" Value="14"/>
    </Style>
    <Style TargetType="{x:Type Calendar}">
        <Setter Property="FontSize" Value="14"/>
    </Style>
    <Style TargetType="{x:Type TextBox}">
        <Setter Property="FontSize" Value="14"/>
    </Style>
</Window.Resources>

<Grid Background="#FFEFEDDF">
    <Grid.RowDefinitions>
        <RowDefinition Height=".5*"/>
        <RowDefinition Height=".5*"/>
        <RowDefinition Height="4*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="*"/>
        <RowDefinition Height="5*"/>
    </Grid.RowDefinitions>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width=".2*"/>
        <ColumnDefinition Width=".7*"/>
        <ColumnDefinition Width=".7*"/>
        <ColumnDefinition Width=".7*"/>
        <ColumnDefinition Width=".5*"/>
        <ColumnDefinition Width="4*"/>
        <ColumnDefinition Width=".1*"/>
    </Grid.ColumnDefinitions>
    <Calendar x:Name="cDatePicker" Grid.Column="1" Grid.Row="2" Grid.RowSpan="2" Grid.ColumnSpan="2" SelectedDatesChanged="cDatePicker_SelectedDatesChanged" />
    <Label Content="Start Date:" Grid.Column="1" Grid.Row="4" Margin="5"/>
    <TextBox x:Name="txtStartDate" Grid.Column="2" Grid.Row="4" Margin="5" VerticalContentAlignment="Center" />
    <Label Content="End Date:" Grid.Column="1" Grid.Row="5" Margin="5"/>
    <TextBox x:Name="txtEndDate" Grid.Column="2" Grid.Row="5" Margin="5" VerticalContentAlignment="Center"/>
    <Label Content="Supplier Number:" Grid.Column="1" Grid.Row="6" Margin="5"/>
    <TextBox x:Name="txtCustomerNumber" Grid.Column="2" Grid.Row="6" Margin="5" VerticalContentAlignment="Center" TabIndex="1" />
    <Button x:Name="btnShowRport" Content="View Report" Grid.Column="1" Grid.Row="8" Margin="0,0,10,0"  Click="btnShowRport_Click" IsDefault="True" />
    <Button x:Name="btnPrintReport" Content=" Print Report" Grid.Column="2" Grid.Row="8" Margin="10,0,0,0"  Click="btnPrintReport_Click" />
    <my:CrystalReportsViewer  x:Name="crReportViewer" Grid.Column="3" Grid.RowSpan="10" HorizontalAlignment="Center" VerticalAlignment="Center" 
                              Height="656" Width="845" Margin="94,-7,62,12" ToggleSidePanel="None" Panel.ZIndex="0" Grid.ColumnSpan="3" 
                              ShowPrintButton="False" ShowRefreshButton="False" ShowSearchTextButton="False" ShowToggleSidePanelButton="True"
                              ShowToolbar="True" ShowNextPageButton="True" ShowGoToPageButton="True" ShowExportButton="False" 
                              ShowCopyButton="False" SnapsToDevicePixels="True" ShowLogo="False" ShowPrevPageButton="True" 
                              ShowStatusbar="True" />
</Grid>

谢谢

Answer 1

有点晚了，但是当你得到像这样的空引用异常时，它可能会产生误导。内部异常可能为空(在我的情况下。)

我发现这个问题的方法是在 VS 2010 中启用第一次机会异常。

转到 调试 -> 异常然后选中所有复选框。