如何将用户控件放在所有其他控件的静态层中?

时间:2015-08-18 06:32:44

标签: c# wpf xaml

我正在使用XAML和C#为WPF开发自动完成用户控件。

我希望弹出窗口显示所有控件上方的建议。目前我的弹出窗口是ListView。这会导致问题,因为每当我决定显示它时,UI必须为它找到一个位置,并且这样做会将其下方的所有控件向下移动。

我该如何避免这种情况?我假设我必须将它放在一个高于所有其他控件的层中?

2 个答案:

答案 0 :(得分:1)

我写了#34;自动完成"之前使用WPF Popup控件控制样式,并结合文本框。如果你使用Popup,它应该像你所说的那样出现在其他一切的顶层。只需使用“底部放置”将其对齐到文本框的底部即可。

这是我刚才写的一个例子。基本上它是一个文本框,当你输入弹出一个建议弹出窗口时,当你输入更多时,它会向下细化选项。如果您需要,可以相当轻松地更改它以支持多字自动完成样式代码编辑情况:

XAML:

<Grid>
    <TextBox x:Name="textBox" 
             Text="{Binding Text, Mode=TwoWay, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:IntelliSenseUserControl}}}" 
             KeyUp="textBox_KeyUp"/>
    <Popup x:Name="popup" 
           Placement="Bottom" 
           PlacementTarget="{Binding ElementName=textBox}" 
           IsOpen="False"
           Width="200" 
           Height="300">
        <ListView x:Name="listView" 
                  ItemsSource="{Binding FilteredItemsSource, RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type local:IntelliSenseUserControl}}}"
                  SelectionChanged="ListView_Selected"/>
    </Popup>
</Grid>

代码隐藏:

public partial class IntelliSenseUserControl : UserControl, INotifyPropertyChanged
{
    public IntelliSenseUserControl()
    {
        InitializeComponent();

        DependencyPropertyDescriptor prop = DependencyPropertyDescriptor.FromProperty(ItemsSourceProperty, typeof(IntelliSenseUserControl));
        prop.AddValueChanged(this, ItemsSourceChanged);
    }


    private void ItemsSourceChanged(object sender, EventArgs e)
    {
        FilteredItemsSource = new ListCollectionView((IList)ItemsSource);
        FilteredItemsSource.Filter = (arg) => { return arg == null || string.IsNullOrEmpty(textBox.Text) || arg.ToString().Contains(textBox.Text.Trim()); };
    }


    public string Text
    {
        get { return (string)GetValue(TextProperty); }
        set { SetValue(TextProperty, value); }
    }

    public static readonly DependencyProperty TextProperty =
        DependencyProperty.Register("Text", typeof(string), typeof(IntelliSenseUserControl), new FrameworkPropertyMetadata(null) { BindsTwoWayByDefault = true });


    public object ItemsSource
    {
        get { return (object)GetValue(ItemsSourceProperty); }
        set { SetValue(ItemsSourceProperty, value); }
    }

    public static readonly DependencyProperty ItemsSourceProperty =
        DependencyProperty.Register("ItemsSource", typeof(object), typeof(IntelliSenseUserControl), new PropertyMetadata(null));


    #region Notified Property - FilteredItemsSource (ListCollectionView)
    public ListCollectionView FilteredItemsSource
    {
        get { return filteredItemsSource; }
        set { filteredItemsSource = value; RaisePropertyChanged("FilteredItemsSource"); }
    }

    private ListCollectionView filteredItemsSource;
    #endregion


    private void textBox_KeyUp(object sender, KeyEventArgs e)
    {
        if (e.Key == Key.Return || e.Key == Key.Enter)
        {
            popup.IsOpen = false;
        }
        else
        {
            popup.IsOpen = true;
            FilteredItemsSource.Refresh();
        }
    }

    private void UserControl_LostFocus(object sender, RoutedEventArgs e)
    {
        popup.IsOpen = false;
    }

    private void ListView_Selected(object sender, RoutedEventArgs e)
    {
        if (listView.SelectedItem != null)
        {
            Text = listView.SelectedItem.ToString().Trim();
        }
    }

    public event PropertyChangedEventHandler PropertyChanged;

    void RaisePropertyChanged(string name)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(name));
        }
    }
}

答案 1 :(得分:1)

如果您的Window的内容容器是网格,您可以简单地执行类似

的操作
<ListBox Grid.RowSpawn="99" Grid.ColumnSpan="99"/>

“模拟”绝对位置。然后,您必须使用Margin, HorizontalAlignment and VerticalAlignment设置其位置,以便它围绕所需的控件。