Error - Cannot find static resource in a WPF application

I'm learning WPF and started with this MSDN tutorial.

I was开发者_开发知识库 just following the tutorial. When I finished the code as per the tutorial and try to run I get an exception in a XAML page which says

'Provide value on 'System.Windows.StaticResourceExtension' threw an exception.' Line number '27' and line position '55'." . And inner exception reveals that error is "Cannot find resource named 'personItemTemplate'. Resource names are case sensitive.".

The culprit XAML is below.

<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="321" d:DesignWidth="532"
    Title="ExpenseIt - Home">

    <Grid Margin="10,0,10,10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="230" />
            <ColumnDefinition />
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition />
            <RowDefinition Height="Auto" />
            <RowDefinition />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Label Grid.Column="1" Style="{StaticResource headerTextStyle}">View Expense Report</Label>
        <!-- Resource List Label-->
        <Border Grid.Column="1" Grid.Row="1" Style="{StaticResource listHeaderStyle}">
            <Label VerticalAlignment="Center" Foreground="White" FontWeight="Bold">Names</Label>
        </Border>
        <!-- Resource List-->
        <ListBox Name="peopleListBox" Grid.Column="1" Grid.Row="2" 
         ItemsSource="{Binding Source={StaticResource ExpenseDataSource}, XPath=Person}"
         ItemTemplate="{StaticResource personItemTemplate}">
        </ListBox>

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

        <!-- Set Background Image-->
        <Grid.Background>
            <ImageBrush ImageSource="watermark.png" />
        </Grid.Background>
        <Grid.Resources>

            <!-- Expense Report Data -->
            <XmlDataProvider x:Key="ExpenseDataSource" XPath="Expenses">
                <x:XData>
                    <Expenses xmlns="">
                        <Person Name="TommyVance" Department="Legal">
                            <Expense ExpenseType="Lunch" ExpenseAmount="50" />
                            <Expense ExpenseType="Transportation" ExpenseAmount="50" />
                        </Person>
                        <Person Name="PhilJackson" Department="Marketing">
                            <Expense ExpenseType="Document printing"
      ExpenseAmount="50"/>
                            <Expense ExpenseType="Gift" ExpenseAmount="125" />
                        </Person>
                        <Person Name="PaulBriggs" Department="Engineering">
                            <Expense ExpenseType="Magazine subscription" 
     ExpenseAmount="50"/>
                            <Expense ExpenseType="New machine" ExpenseAmount="600" />
                            <Expense ExpenseType="Software" ExpenseAmount="500" />
                        </Person>
                        <Person Name="AlfredNobel" Department="Finance">
                            <Expense ExpenseType="Dinner" ExpenseAmount="100" />
                        </Person>
                    </Expenses>
                </x:XData>
            </XmlDataProvider>
            <!-- Data Template to mention that Name should be fetched from the XMLDataProvider -->
            <!-- Name item template -->
            <DataTemplate x:Key="personItemTemplate">
                <Label Content="{Binding XPath=@Name}"/>
            </DataTemplate>
        </Grid.Resources>
    </Grid>
</Page>

I have the required template inside the Grid resources and so adding it as a static resource. Still, it throws the exception that the datatemplate is not available.

Move the <Grid.Resources> ... </Grid.Resources> to the top of your grid definition and it will work. The DataTemplate appears to need to be defined before it is referenced. I copied your sample into an app and confirmed that moving the Resources section up solved the problem.

There are several reasons for this error. The solution to my proplem was that I failed to add a "InitializeComponent();" in the constructor of Application therefore the Xaml containing the ResourceDictionary was never initialized. Hence the error "Can not find..." I failed to mention that I am hand-coding. If you generating code via Visual Studio, this is not required.

I got the same error, but none of the answers above worked.

My error got solved by changing the XAML on the datatemplate from :

<DataTemplate DataType="local:DtoDmParent" x:Key="dataTemplateDtoDmParent"  >
    <TextBlock Text="test"/>
</DataTemplate>

to

<DataTemplate x:Key="dataTemplateDtoDmParent" DataType="local:DtoDmParent" >
    <TextBlock Text="test"/>
</DataTemplate>

Changing so the Datatype parameter was after the x:key parameter