如何定位WPF控件旁边的控件与当前焦点

本文关键字：控件 焦点 定位 WPF 何定位 | 更新日期: 2023-09-27 18:11:24

我有一个典型的edit form (user control)，有几个输入框。我需要一个ListBox，它必须显示在当前焦点TextBox的正下方，所以它需要动态移动。我尝试了一些绑定，但没有任何反应

<local:MyList x:Name="myList"
       Canvas.Left="{Binding (FocusManager.FocusedElement).Canvas.Left,RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}}}"
       Canvas.Top="{Binding (FocusManager.FocusedElement).Canvas.Bottom,RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}}}"
/>

如何定位WPF控件旁边的控件与当前焦点

使用Popup，因为它可以方便地在需要的地方显示它。它的Placement = Bottom将显示它正好低于PlacementTarget。

处理TextBox的GotFocus和LostFocus。

        <TextBox Grid.Column="1" HorizontalAlignment="Left" Height="23" Margin="10,19,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120" GotFocus="TextBox_GotFocus_1" LostFocus="TextBox_LostFocus_1"/>
        <TextBox Grid.Column="1" HorizontalAlignment="Left" Height="23" Margin="10,57,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120" GotFocus="TextBox_GotFocus_1" LostFocus="TextBox_LostFocus_1"/>
        <TextBox Grid.Column="1" HorizontalAlignment="Left" Height="23" Margin="10,96,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120"/>
        <TextBox Grid.Column="1" HorizontalAlignment="Left" Height="23" Margin="10,136,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120" GotFocus="TextBox_GotFocus_1" LostFocus="TextBox_LostFocus_1"/>
        <TextBox Grid.Column="1" HorizontalAlignment="Left" Height="23" Margin="10,174,0,0" TextWrapping="Wrap" Text="TextBox" VerticalAlignment="Top" Width="120"/>
        <Popup Placement="Bottom" x:Name="LsbPopup">
            <ListBox>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
                <ListBoxItem>item1</ListBoxItem>
            </ListBox>
        </Popup>

处理器:

private void TextBox_GotFocus_1(object sender, RoutedEventArgs e)
{
    LsbPopup.PlacementTarget = sender as TextBox;
    LsbPopup.IsOpen = true;
}
private void TextBox_LostFocus_1(object sender, RoutedEventArgs e)
{
    LsbPopup.IsOpen = false;
}
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