同时使用 GotFocus 和 TextChanged - Windows Phone

Question

我有一个 AutoSuggestBox 设置为同时处理事件 GotFocus & TextChanged。我已经清除了 GotFocus 事件中文本框中的文本。现在的问题是，当我 select AutoSuggestBox 中的任何建议时，在 selecting 之后它调用 GotFocus 事件处理程序并清除 select从中编辑文本。

这是使用 AutoSuggestBox 的 MainPage.xaml 代码：

        <AutoSuggestBox
            x:Name="auto_text_from"
            HorizontalAlignment="Left"
            VerticalAlignment="Center"
            PlaceholderText="Enter Source"
            Height="auto"
            Width="280"
            GotFocus="auto_text_from_GotFocus"
            TextChanged="AutoSuggestBox_TextChanged"/>

这是我在 MainPage.xaml.cs 中编写的代码：

    private void auto_text_from_GotFocus(object sender, RoutedEventArgs e)
    {
        auto_text_from.Text = "";
    }


    string[] PreviouslyDefinedStringArray = new string[] {"Alwar","Ajmer","Bharatpur","Bhilwara",
        "Banswada","Jaipur","Jodhpur","Kota","Udaipur"};


    private void AutoSuggestBox_TextChanged(AutoSuggestBox sender,AutoSuggestBoxTextChangedEventArgs args)
    {
        List<string> myList = new List<string>();
        foreach (string myString in PreviouslyDefinedStringArray)
        {
            if (myString.ToLower().Contains(sender.Text.ToLower()) == true)
            {
                myList.Add(myString);
            }
        }
        sender.ItemsSource = myList;
    }

我想同时使用这两个事件处理程序。 GotFocus用于清除文本框的数据，TextChanged用于显示在其中写入文本的建议。

请建议我做同样的事情。

提前致谢:)

Answer 1

如果 AutoSuggestBox 有一个事件来处理建议词的选择，例如“SuggestionChosen”，一个可能的解决方案是使用在各种处理程序之间管理的私有标志。

设置私有字段：

private bool _isSelectingSuggestion;

Link 像 OnSuggestionChosen 这样的方法处理程序到事件 SuggestionChosen 并像这样实现它：

private void OnSuggestionChosen(object sender, RoutedEventArgs e)
{
    _isSelectingSuggestion = true;
}

然后，在 GotFocus 中，像这样检查标志：

private void auto_text_from_GotFocus(object sender, RoutedEventArgs e)
{
    if (_isSelectingSuggestion)
        e.Handled = true;
    else
        auto_text_from.Text = "";

   _isSelectingSuggestion = false;
}

显然这仅在 GotFocus 之前引发 SuggestionChosen 时有效：当 GotFocus 开始时，它会像这样进行："ok, I've got focus because a suggestion was chosen just a moment ago? If it's true, I must not clear my Text! Otherwise, I shall clear it!".

告诉我这对你有用！

Answer 2

@MK87：是的，稍作改动就可以了！！ :)

    private bool _isSelectingSuggestion;

    private void OnSuggestionChosen(AutoSuggestBox sender, AutoSuggestBoxSuggestionChosenEventArgs args)
    {
        _isSelectingSuggestion = true;
    }

    private void auto_text_from_GotFocus(object sender, RoutedEventArgs e)
    {
        if (!_isSelectingSuggestion)
            auto_text_from.Text = "";

        _isSelectingSuggestion = false;
    }

我不得不删除这一行：

e.Handled == true;

因为它给我的错误是 RoutedEventArgs does not contain a definition for 'Handled'。

感谢您的帮助:) :)

同时使用 GotFocus 和 TextChanged - Windows Phone

Using GotFocus and TextChanged simultaneously - Windows Phone

c#

xaml

event-handling

visual-studio

windows-phone