从后面的代码更改 booleanToVisibilityConverter - wpf c #

Question

<Page.Resources>
    <ResourceDictionary>
        <BooleanToVisibilityConverter x:Key="booleanToVisibilityConverter" x:Name="testTest" />
    </ResourceDictionary>
</Page.Resources>

项目控制：

<Grid Grid.Row="1" Grid.ColumnSpan="2" Name="testName">
            <ScrollViewer VerticalScrollBarVisibility="Hidden" PanningMode="Both">
                <ItemsControl ItemsSource="{Binding Path=NextMeetingList}">
                    <ItemsControl.ItemTemplate>
                        <DataTemplate>
                            <StackPanel Grid.Column="0" Grid.Row="0">
                                <Border x:Name = "myVariable" Grid.Column="0" Grid.Row="0" Margin="10" Height="30" Background="#A2C2E7" CornerRadius="5" BorderBrush="#A2C2E7">
                                    <Grid Margin="8,0,8,0" Background="#A2C2E7">
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="1*"></ColumnDefinition>
                                            <ColumnDefinition Width="1*"></ColumnDefinition>
                                        </Grid.ColumnDefinitions>
                                        <Grid.RowDefinitions>
                                            <RowDefinition Height="30"/>
                                        </Grid.RowDefinitions>
                                        <TextBlock Grid.Row="0" Grid.Column="0" Foreground="White" FontWeight="Bold" FontSize="15" Margin="0,4,0,0" HorizontalAlignment="Left">month</TextBlock>
                                        <TextBlock Grid.Row="0" Grid.Column="1"  Foreground="White" FontWeight="Bold" FontSize="15" Margin="0,4,0,0" HorizontalAlignment="Right">1 Meeting</TextBlock>
                                    </Grid>
                                </Border>
                                <Border Grid.Column="0" Grid.Row="0" Margin="10" Height="60" Background="GhostWhite" CornerRadius="3" BorderBrush="{Binding BorderColor}" BorderThickness="0,8,0,0">
                                    <Grid>
                                        <Grid.ColumnDefinitions>
                                            <ColumnDefinition Width="118"></ColumnDefinition>
                                            <ColumnDefinition Width="*"></ColumnDefinition>
                                        </Grid.ColumnDefinitions>
                                        <Grid.RowDefinitions>
                                            <RowDefinition Height="60"/>
                                        </Grid.RowDefinitions>
                                        <TextBlock Grid.Row="0" Grid.Column="0" HorizontalAlignment="Left" FontSize="40" Margin="10,5,0,0" Style="{DynamicResource Lato-Semibold}" Text="{Binding endDate.Day}"/>
                                        <TextBlock Grid.Row="0" Grid.Column="0" HorizontalAlignment="Left" FontSize="12" Margin="77,13,0,0" Height="Auto" Style="{DynamicResource Lato-Semibold}" Text="{Binding DayString}"/>
                                        <TextBlock Grid.Row="0" Grid.Column="0" HorizontalAlignment="Left" FontSize="14" Margin="70,26,0,0" Height="Auto" Style="{DynamicResource Lato-Semibold}" Text="{Binding endDate.Hour}"/>
                                        <TextBlock Grid.Row="0" Grid.Column="0" HorizontalAlignment="Left" FontSize="14" Margin="86,26,0,0" Height="Auto" Style="{DynamicResource Lato-Semibold}" Text=":"/>
                                        <TextBlock Grid.Row="0" Grid.Column="0" HorizontalAlignment="Left" FontSize="14" Margin="90,26,0,0" Height="Auto" Style="{DynamicResource Lato-Semibold}" Text="{Binding MinuteString}"/>
                                        <Border Grid.Row="0" Grid.Column="0" Width="1" BorderBrush="#BABABA" Height="40" Margin="115,-6,0,0" BorderThickness="1" HorizontalAlignment="Left"></Border>
                                        <TextBlock Grid.Row="0" Grid.Column="1" HorizontalAlignment="Left" Text="{Binding subject}" FontWeight="Bold" FontSize="17" Margin="10,10,0,0"/>
                                        <TextBlock Grid.Row="0" Grid.Column="1" Width="Auto" TextWrapping="Wrap" HorizontalAlignment="Left" Text="{Binding descr}" FontSize="10"  Margin="20,27,150,0"/>
                                        <TextBlock Grid.Row="0" Grid.Column="1" HorizontalAlignment="Right" Text="{Binding companyName}" FontSize="10" Margin="0,10,30,0"/>
                                        <TextBlock Grid.Row="0" Grid.Column="1" HorizontalAlignment="Right" Text="sala del consiglio" FontSize="10" Margin="0,27,30,0"/>
                                        <TextBlock Grid.Row="0" Grid.Column="1" HorizontalAlignment="Right" Text=">" FontSize="15" VerticalAlignment="Center" Margin="0,-5,10,0"/>
                                    </Grid>
                                </Border>
                            </StackPanel>                                    
                        </DataTemplate>
                    </ItemsControl.ItemTemplate>
                </ItemsControl>
            </ScrollViewer>
        </Grid>

大家好，我应该可以在 WPF 中的 ItemsControl 内制作一个 Collapsed 网格。

问题是我无法理解如何从后面的代码中使用 booleanToVisibilityConverter。 也许我错过了一杯水，但我无法连接怎么办，如果名称 TestTest septum 看不到它，那么代码隐藏。

从后面的代码中我看不到“myVariable”

Answer 1

要从代码隐藏中获取转换器，您必须在 Page 的 Resources 字典中查找它。在你的 Page 课堂上做这样的事情：

IValueConverter converter = this.Resources["booleanToVisibilityConverter"] as IValueConverter;

无需为转换器的资源条目提供Name；在这里你要使用Key。此外，转换器通常与 XAML 绑定一起使用——如果您想要在代码中使用一个，您可以只实例化一个：

IValueConverter converter = new BooleanToVisibilityConverter();

---

常见的用法是这样的：

<Window.Resources>
    <ResourceDictionary>
        <BooleanToVisibilityConverter x:Key="Converter" />
    </ResourceDictionary>
</Window.Resources>
<Grid Visibility="{Binding Display, Converter={StaticResource Converter}}">
    ...
</Grid>

代码隐藏，使用窗口类本身作为数据上下文：

public partial class MainWindow
{
    public bool Display { get; set; };

    public MainWindow()
    {
        InitializeComponent();
        DataContext = this; // For the binding
        Display = true;
    }
}

---

好的，再来一个，这次没有数据绑定或转换器：

<Grid x:Name="myGrid">
    ...
</Grid>

代码隐藏：

public partial class MainWindow
{
    public MainWindow()
    {
        InitializeComponent();
        myGrid.Visibility = Visibility.Visible;
    }
}

---

上面没有解释为什么 OP 不能从代码隐藏中引用“myVariable”。这是因为它位于模板中，该模板在集合中的每个项目（动态）实例化一次。

仍然可以从代码中获得它——动态地。例如，此 XAML 使用 DataTemplate:

<ItemsControl ItemsSource="{Binding Names}">
    <ItemsControl.ItemTemplate>
        <DataTemplate>
            <Grid>
                <Grid x:Name="innerGrid" Loaded="OnGridLoaded" DataContext="{Binding Name, Mode=OneWay}">
                    <TextBox Text="{Binding Path=., Mode=OneWay}" />
                </Grid>
            </Grid>
        </DataTemplate>
    </ItemsControl.ItemTemplate>
</ItemsControl>

以下代码隐藏让我们可以进入模板并选择性地使“innerGrid”消失：

public class Data
{
    public string Name { get; }

    public Data(string name)
    {
        Name = name;
    }
}

public partial class MainWindow
{
    public Data[] Names { get; } = { new Data("Hello"), new Data("World") };

    public MainWindow()
    {
        InitializeComponent();
        DataContext = this;
    }

    private void OnGridLoaded(object sender, RoutedEventArgs e)
    {
        Grid outerGrid = sender as Grid;
        Grid innerGrid = outerGrid?.FindName("innerGrid") as Grid;
        if (innerGrid != null)
        {
            string name = innerGrid.DataContext as string;
            if (name == "Hello")
            {
                innerGrid.Visibility = Visibility.Collapsed;
            }
        }
    }
}

（为了使字符串易于访问，我将Data 对象绑定到“innerGrid”DataContext。）