如何查找在DocumentViewer工具欄中創建的控件？

Question

我在DocumentViewer的工具欄中創建了一個TextBox控件，用於顯示當前頁碼。並給用戶一個GoTo類型的工具。

以下是代碼：

<Style x:Key="DocumentViewerStyle1" BasedOn="{x:Null}" TargetType="{x:Type DocumentViewer}"> 
     <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/> 
     <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/> 
     <Setter Property="FocusVisualStyle" Value="{x:Null}"/> 
     <Setter Property="ContextMenu" Value="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerContextMenu, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}"/> 
     <Setter Property="Template"> 
      <Setter.Value> 
       <ControlTemplate TargetType="{x:Type DocumentViewer}"> 
        <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Focusable="False"> 
         <Grid Background="{TemplateBinding Background}" KeyboardNavigation.TabNavigation="Local"> 
          <Grid.ColumnDefinitions> 
           <ColumnDefinition Width="*"/> 
          </Grid.ColumnDefinitions> 
          <Grid.RowDefinitions> 
           <RowDefinition Height="Auto"/> 
           <RowDefinition Height="*"/> 
           <RowDefinition Height="Auto"/> 
          </Grid.RowDefinitions> 
          <ContentControl Grid.Column="0" Focusable="{TemplateBinding Focusable}" Grid.Row="0" Style="{DynamicResource ContentControlStyle1}" TabIndex="0"/> 
          <ScrollViewer x:Name="PART_ContentHost" CanContentScroll="true" Grid.Column="0" Focusable="{TemplateBinding Focusable}" HorizontalScrollBarVisibility="Auto" IsTabStop="true" Grid.Row="1" TabIndex="1"/> 
          <DockPanel Grid.Row="1"> 
           <FrameworkElement DockPanel.Dock="Right" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}"/> 
           <Rectangle Height="10" Visibility="Visible" VerticalAlignment="top"> 
            <Rectangle.Fill> 
             <LinearGradientBrush EndPoint="0,1" StartPoint="0,0"> 
              <LinearGradientBrush.GradientStops> 
               <GradientStopCollection> 
                <GradientStop Color="#66000000" Offset="0"/> 
                <GradientStop Color="Transparent" Offset="1"/> 
               </GradientStopCollection> 
              </LinearGradientBrush.GradientStops> 
             </LinearGradientBrush> 
            </Rectangle.Fill> 
           </Rectangle> 

           <!--<Image Grid.Column="0" Grid.Row="2" Width="100"/>--> 
          </DockPanel> 
          <!--<TextBlock Grid.Row="2" Grid.Column="0" x:Name="txtBlock" Text="Hello World"/>--> 
          <ContentControl x:Name="PART_FindToolBarHost" Grid.Column="0" Focusable="{TemplateBinding Focusable}" Grid.Row="2" TabIndex="2"/> 
          <TextBlock Text="Aspire Education" Grid.Row="2" Grid.Column="0" Margin="300,0,0,0" Foreground="#FF0758DC" FontSize="18" /> 
         </Grid> 
        </Border> 
       </ControlTemplate> 
      </Setter.Value> 
     </Setter> 
    </Style> 
    <Style x:Key="ContentControlStyle1" TargetType="{x:Type ContentControl}"> 
     <Setter Property="Template"> 
      <Setter.Value> 
       <ControlTemplate TargetType="{x:Type ContentControl}"> 
        <ToolBar Focusable="{TemplateBinding Focusable}" ToolBarTray.IsLocked="True" Language="en-us" KeyboardNavigation.TabNavigation="Continue" Uid="ToolBar_2"> 
         <Button x:Name="PrintButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerPrintButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" Command="ApplicationCommands.Print" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="0" ToolTip="Print (Ctrl+P)" Uid="Button_14" VerticalAlignment="Center" Width="24"/> 
         <Button x:Name="CopyButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerCopyButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" Command="ApplicationCommands.Copy" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="1" ToolTip="Copy (Ctrl+C)" Uid="Button_15" VerticalAlignment="Center" Width="24"/> 
         <Separator Uid="Separator_110"/> 
         <Button x:Name="ZoomInButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerZoomInButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" Command="NavigationCommands.IncreaseZoom" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="3" ToolTip="Increase the size of the content (Ctrl +)" Uid="Button_16" VerticalAlignment="Center" Width="24"/> 
         <Button x:Name="ZoomOutButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerZoomOutButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" Command="NavigationCommands.DecreaseZoom" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="4" ToolTip="Decrease the size of the content (Ctrl -)" Uid="Button_17" VerticalAlignment="Center" Width="24"/> 
         <Separator Uid="Separator_111"/> 
         <Button x:Name="ActualSizeButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerActualSizeButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" CommandParameter="100.0" Command="NavigationCommands.Zoom" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource ButtonStyle1}" ToolTipService.ShowOnDisabled="True" TabIndex="5" ToolTip="100% (Ctrl+1)" Uid="Button_18" VerticalAlignment="Center" Width="24"/> 
         <Button x:Name="PageWidthButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerPageWidthButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" Command="DocumentViewer.FitToWidthCommand" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="6" ToolTip="Page Width (Ctrl+2)" Uid="Button_19" VerticalAlignment="Center" Width="24"/> 
         <Button x:Name="WholePageButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerWholePageButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" CommandParameter="1" Command="DocumentViewer.FitToMaxPagesAcrossCommand" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="7" ToolTip="Whole Page (Ctrl+3)" Uid="Button_20" VerticalAlignment="Center" Width="24"/> 
         <Button x:Name="TwoPagesButton" Background="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerTwoPagesButton, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" CommandTarget="{Binding TemplatedParent, RelativeSource={RelativeSource TemplatedParent}}" CommandParameter="2" Command="DocumentViewer.FitToMaxPagesAcrossCommand" IsTabStop="True" Margin="2" Padding="2" Style="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerButtonStyle, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}" ToolTipService.ShowOnDisabled="True" TabIndex="8" ToolTip="Two Pages (Ctrl+4)" Uid="Button_21" VerticalAlignment="Center" Width="24"/> 
         <Separator Uid="Separator_112"/> 
         <TextBox x:Name="txtCurrentPage" Text="580" Width="30" BorderBrush="Black" TextChanged="txtCurrentPage_TextChanged"></TextBox> 
         <TextBox x:Name="txtTotalPage" Text="/250" Width="40" IsReadOnly="True" BorderBrush="Black" Foreground="Black"></TextBox> 
        </ToolBar> 
       </ControlTemplate> 
      </Setter.Value> 
     </Setter> 
    </Style> 

但是，當我試圖訪問該文本框，它顯示爲空。

這裏是我的代碼背後。

private void txtCurrentPage_TextChanged(object sender, TextChangedEventArgs e) 
    { 
     MainWindow mn = new MainWindow(); 
     TextBox tb = (TextBox)mn.FindName("txtCurrentPage"); 

     if (tb != null) 
     { 
      DocumentViewerReading.GoToPage(Convert.ToInt32(tb.Text)); 
     } 
    } 

請幫助

Answer 1

下面是完整的解決方案： -

<Style x:Key="DocumentViewerStyle1" BasedOn="{x:Null}" TargetType="{x:Type DocumentViewer}"> 
     <Setter Property="Foreground" Value="{DynamicResource {x:Static SystemColors.WindowTextBrushKey}}"/> 
     <Setter Property="Background" Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}"/> 
     <Setter Property="FocusVisualStyle" Value="{x:Null}"/> 
     <Setter Property="ContextMenu" Value="{DynamicResource {ComponentResourceKey ResourceId=PUIDocumentViewerContextMenu, TypeInTargetAssembly={x:Type System_Windows_Documents:PresentationUIStyleResources}}}"/> 
     <Setter Property="Template"> 
      <Setter.Value> 
       <ControlTemplate TargetType="{x:Type DocumentViewer}"> 
        <Border BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Focusable="False"> 
         <Grid x:Name="grdDocumentViewer" Background="{TemplateBinding Background}" KeyboardNavigation.TabNavigation="Local"> 
          <Grid.ColumnDefinitions> 
           <ColumnDefinition Width="*"/> 
          </Grid.ColumnDefinitions> 
          <Grid.RowDefinitions> 
           <RowDefinition Height="Auto"/> 
           <RowDefinition Height="*"/> 
           <RowDefinition Height="Auto"/> 
          </Grid.RowDefinitions> 
          <ContentControl Grid.Column="0" Focusable="{TemplateBinding Focusable}" Grid.Row="0" Style="{DynamicResource ContentControlStyle1}" TabIndex="0"/> 
          <ScrollViewer x:Name="PART_ContentHost" CanContentScroll="true" Grid.Column="0" Focusable="{TemplateBinding Focusable}" HorizontalScrollBarVisibility="Auto" IsTabStop="true" Grid.Row="1" TabIndex="1"/> 
          <DockPanel Grid.Row="1"> 
           <FrameworkElement DockPanel.Dock="Right" Width="{DynamicResource {x:Static SystemParameters.VerticalScrollBarWidthKey}}"/> 
           <Rectangle Height="10" Visibility="Visible" VerticalAlignment="top"> 
            <Rectangle.Fill> 
             <LinearGradientBrush EndPoint="0,1" StartPoint="0,0"> 
              <LinearGradientBrush.GradientStops> 
               <GradientStopCollection> 
                <GradientStop Color="#66000000" Offset="0"/> 
                <GradientStop Color="Transparent" Offset="1"/> 
               </GradientStopCollection> 
              </LinearGradientBrush.GradientStops> 
             </LinearGradientBrush> 
            </Rectangle.Fill> 
           </Rectangle> 

           <!--<Image Grid.Column="0" Grid.Row="2" Width="100"/>--> 
          </DockPanel> 
          <!--<TextBlock Grid.Row="2" Grid.Column="0" x:Name="txtBlock" Text="Hello World"/>--> 
          <ContentControl x:Name="PART_FindToolBarHost" Grid.Column="0" Focusable="{TemplateBinding Focusable}" HorizontalAlignment="Right" Margin="0,0,20,0" Grid.Row="0" TabIndex="2"/> 
          <TextBlock x:Name="tbTopicName" Text="" Grid.Row="0" Grid.Column="0" HorizontalAlignment="Center" Margin="0,2,0,0" Foreground="#FF0758DC" FontSize="20" /> 
         </Grid> 
        </Border> 
       </ControlTemplate> 
      </Setter.Value> 
     </Setter> 
    </Style> 

// 而以下是後面的代碼

Grid gMain = (Grid)DocumentViewerReading.Template.FindName("grdDocumentViewer", DocumentViewerReading); 
     TextBlock tb = (TextBlock)gMain.FindName("tbTopicName"); 
     tb.Text = header; 

就是這樣。 並感謝安迪。

Answer 2

你並不需要再次找到控制，它的參考應該在sender參數。

private void txtCurrentPage_TextChanged(object sender, TextChangedEventArgs e) 
    { 
     TextBox tb = (TextBox)sender; 

     if (tb != null) 
     { 
      DocumentViewerReading.GoToPage(Convert.ToInt32(tb.Text)); 
     } 
    } 

你正在創建一個窗口的新實例每次的文本框的內容發生變化時，並試圖尋找一個新窗口中的文本框，這並不完全是應該如何工作，你已經有了一個窗口的實例，因爲用戶正在輸入它。