Question

我正在使用WPF Popup。弹出窗口包含一些键盘。我想在用户点击文本框时打开弹出窗口，并且在文本框具有焦点时不隐藏弹出窗口。此外，当用户点击远离弹出窗口的某个地方时，我需要隐藏弹出窗口。这是xaml代码：

<Grid>
    <StackPanel>
        <TextBox  x:Name="textBox" GotKeyboardFocus="textBox_GotFocus" MouseDown="textBox_MouseDown" />

        <Popup x:Name="popup" Width="100" Height="100" PlacementTarget="{Binding ElementName=textBox}" Placement="Bottom"
        StaysOpen="{Binding ElementName=text,Path=IsKeyboardFocused}">
            <Grid Background="Blue">

            </Grid>
        </Popup>

    </StackPanel>
</Grid>

这是c＃代码：

 private void textBox_GotFocus(object sender, KeyboardFocusChangedEventArgs e)
        {
            popup.IsOpen = true;
        }

private void textBox_MouseDown(object sender, MouseButtonEventArgs e)
        {
            popup.IsOpen = true;
        }

我发现绑定可以帮助：

StaysOpen="{Binding ElementName=,Path=IsKeyboardFocused}"

但TextBox永远不会隐藏。如果我设置StaysOpen =＆＃34; False＆＃34; TextBox永远不会显示

Answer 1

您可以处理LostKeyboardFocus事件并检查新的焦点元素是TextBox本身还是Popup的子元素：

private void textBox_GotFocus(object sender, KeyboardFocusChangedEventArgs e)
{
    popup.IsOpen = true;
}

private void textBox_LostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
    var newFocusedElement = e.NewFocus as DependencyObject;
    //if the focused element is a child of the window, it can't be the child of the popup
    if (newFocusedElement == null || FindParent<Window>(newFocusedElement) != null)
        popup.IsOpen = false;

}

private void popup_LostKeyboardFocus(object sender, KeyboardFocusChangedEventArgs e)
{
    popup.IsOpen = e.NewFocus == textBox;
}

private static T FindParent<T>(DependencyObject dependencyObject) where T : DependencyObject
{
    var parent = VisualTreeHelper.GetParent(dependencyObject);

    if (parent == null) return null;

    var parentT = parent as T;
    return parentT ?? FindParent<T>(parent);
}

示例XAML：

<StackPanel>
    <TextBox x:Name="textBox" GotKeyboardFocus="textBox_GotFocus" LostKeyboardFocus="textBox_LostKeyboardFocus" />

    <Popup x:Name="popup" Width="100" Height="100" PlacementTarget="{Binding ElementName=textBox}"
                   LostKeyboardFocus="popup_LostKeyboardFocus"
                   Placement="Bottom">
        <Grid x:Name="popupRoot" Background="Blue">
            <TextBox Margin="10" />
        </Grid>
    </Popup>

    <TextBox />

</StackPanel>

WPF TextBox弹出窗口

1 个答案: