Question

我正在尝试使用示例here: Windows sample WPF application构建WPF应用程序。但是，当我完成它时，我收到以下错误

'在'System.Windows.StaticResourceExtension'上提供值引发异常。行号“36”和行位置“55”。

它抛出以下一行

 <ListBox Name="peopleListBox" Grid.Column="1" Grid.Row="2" 
         ItemsSource="{Binding Source={StaticResource ExpenseDataSource}, XPath=Person}"
         ItemTemplate="{StaticResource nameItemTemplate}">
        </ListBox>

内部异常提供以下详细信息

{“找不到名为'nameItemTemplate'的资源。资源名称区分大小写。”}

这是有问题的xaml。

<Page x:Class="ExpenseIt.ExpenseItHome"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      mc:Ignorable="d" 
      d:DesignHeight="300" d:DesignWidth="300"
    Title="ExpenseIt-Home">

    <Grid Margin="10,0,10,10">
        <Grid.Background>
            <ImageBrush ImageSource="2012-12-20 13.27.57.jpg"  />
        </Grid.Background>

        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="230" />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>

        <Grid.RowDefinitions>
            <RowDefinition/>
            <RowDefinition Height="Auto"/>
            <RowDefinition />
            <RowDefinition Height="Auto"/>
        </Grid.RowDefinitions>

        <!-- People list -->

        <Label Grid.Column="1" Style="{StaticResource headerTextStyle}" >
            View Expense Report
        </Label>

        <Border Grid.Column="1" Grid.Row="1" Style="{StaticResource listHeaderStyle}">
            <Label Style="{StaticResource listHeaderTextStyle}">Names</Label>
        </Border>
        <ListBox Name="peopleListBox" Grid.Column="1" Grid.Row="2" 
         ItemsSource="{Binding Source={StaticResource ExpenseDataSource}, XPath=Person}"
         ItemTemplate="{StaticResource nameItemTemplate}">
        </ListBox>



        <!-- View report button -->
        <Button Grid.Column="1" Grid.Row="3" Click="Button_Click" Style="{StaticResource buttonStyle}">View</Button>
        <Grid.Resources>

            <!-- Expense Report Data -->
            <XmlDataProvider x:Key="ExpenseDataSource" XPath="Expenses">
                <x:XData>
                    <Expenses xmlns="">
                        <Person Name="Mike" Department="Legal">
                            <Expense ExpenseType="Lunch" ExpenseAmount="50" />
                            <Expense ExpenseType="Transportation" ExpenseAmount="50" />
                        </Person>
                        <Person Name="Lisa" Department="Marketing">
                            <Expense ExpenseType="Document printing"
      ExpenseAmount="50"/>
                            <Expense ExpenseType="Gift" ExpenseAmount="125" />
                        </Person>
                        <Person Name="John" Department="Engineering">
                            <Expense ExpenseType="Magazine subscription" 
     ExpenseAmount="50"/>
                            <Expense ExpenseType="New machine" ExpenseAmount="600" />
                            <Expense ExpenseType="Software" ExpenseAmount="500" />
                        </Person>
                        <Person Name="Mary" Department="Finance">
                            <Expense ExpenseType="Dinner" ExpenseAmount="100" />
                        </Person>
                    </Expenses>
                </x:XData>
            </XmlDataProvider>


            <!-- Name item template -->
            <DataTemplate x:Key="nameItemTemplate">
                <Label Content="{Binding XPath=@Name}"/>// isnt this enough?
            </DataTemplate> 
        </Grid.Resources>
    </Grid>
</Page>

任何有关我做错事以及如何纠正错误的帮助，将不胜感激！谢谢！

Answer 1

此错误表示未找到StaticResource密钥。使用静态资源时，必须在引用之前定义它们，无论是在App.Xaml中还是在当前文件中。

因此，请确保示例中的“ExpenseDataSource”和“nameItemTemplate”包含在顶级Grid.Resources下：

<Page ...>
    <Grid ...>
        <Grid.Resources>
            <!-- Name item template -->
            <DataTemplate x:Key="nameItemTemplate">
                <Label Content="{Binding XPath=@Name}"/>
            </DataTemplate>

            <!-- Expense Report Data -->
            <XmlDataProvider x:Key="ExpenseDataSource" XPath="Expenses"> 
                ...

        </Grid.Resources>

        <ListBox Name="peopleListBox" 
            ItemsSource="{Binding Source={StaticResource ExpenseDataSource}, XPath=Person}"
            ItemTemplate="{StaticResource nameItemTemplate}">

新手错误：WPF应用程序中出现XamlParseException

1 个答案: