WPF DatePicker 使分隔符固定并始终可见

Question

我正在开发一个 WPF 应用程序，我想在其中使用默认的 DatePicker 控件。我也想让用户手动插入日期，但我想防止分隔符（“/”）被用户删除。 （更准确地说，即使 DatePicker 的文本框是“空的”，分隔符应该仍然存在）

可以在不创建新的自定义控件的情况下完成此操作吗？谢谢！

Answer 1

我做了以下示例：

<DatePicker HorizontalAlignment="Left" Margin="132,118,0,0" VerticalAlignment="Top" Width="204" Name="DatePicker"
                    SelectedDateChanged="DatePicker_OnSelectedDateChanged">
            <DatePicker.Resources>
                <Style TargetType="{x:Type DatePickerTextBox}">
                    <Setter Property="Template">
                        <Setter.Value>
                            <ControlTemplate>
                                <Grid>

                                    <Grid.ColumnDefinitions>
                                        <ColumnDefinition/>
                                        <ColumnDefinition/>
                                        <ColumnDefinition/>
                                        <ColumnDefinition/>
                                        <ColumnDefinition/>
                                    </Grid.ColumnDefinitions>

                                    <TextBox x:Name="TextBox1" Grid.Column="0" 
                                             Style="{StaticResource DatePickerTextBoxStyle}"
                                             TextChanged="OnTextboxTextChanged1" PreviewTextInput="OnPreviewTextInput1"/>
                                    <Label Grid.Column="1" Content="/" FontSize="18" HorizontalAlignment="Center"/>
                                    <TextBox x:Name="TextBox2" Grid.Column="2" Style="{StaticResource DatePickerTextBoxStyle}"
                                             TextChanged="OnTextboxTextChanged2" PreviewTextInput="OnPreviewTextInput2"/>
                                    <Label Grid.Column="3" Content="/" FontSize="18" HorizontalAlignment="Center"/>
                                    <TextBox x:Name="TextBox3" Grid.Column="4" Style="{StaticResource DatePickerTextBoxStyle}"
                                             TextChanged="OnTextboxTextChanged3" PreviewTextInput="OnPreviewTextInput3"/>
                                </Grid>
                            </ControlTemplate>
                        </Setter.Value>
                    </Setter>
                </Style>
            </DatePicker.Resources>
        </DatePicker>

在你的代码隐藏中：

public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

        }

        private static void TrimText(TextBox textbox)
        {
            textbox.Text = textbox.Text.Trim();
            if (textbox.Text.Length == 2) textbox.Text = textbox.Text.PadLeft(2, '0');
            textbox.CaretIndex = textbox.Text.Length;
        }

        private void OnTextboxTextChanged1(object sender, TextChangedEventArgs e)
        {
            var textbox = sender as TextBox;
            if (textbox == null) return;
            TrimText(textbox);
            if (textbox.Text.Length != 2) return;
            var datePickerTxtBox = DatePicker.Template.FindName("PART_TextBox", DatePicker) as DatePickerTextBox;
            var secondTxtbox = datePickerTxtBox.Template.FindName("TextBox2", datePickerTxtBox) as TextBox;
            secondTxtbox.Focus();
        }

        private void OnTextboxTextChanged2(object sender, TextChangedEventArgs e)
        {
            var textbox = sender as TextBox;
            if (textbox == null) return;
            TrimText(textbox);
            if (textbox.Text.Length != 2) return;
            var datePickerTxtBox = DatePicker.Template.FindName("PART_TextBox", DatePicker) as DatePickerTextBox;
            var thirdTxtbox = datePickerTxtBox.Template.FindName("TextBox3", datePickerTxtBox) as TextBox;
            thirdTxtbox.Focus();
        }

        private void OnTextboxTextChanged3(object sender, TextChangedEventArgs e)
        {
            var textbox = sender as TextBox;
            if (textbox == null) return;
            TrimText(textbox);
            if (textbox.Text.Length != 2) return;
            var datePickerTxtBox = DatePicker.Template.FindName("PART_TextBox", DatePicker) as DatePickerTextBox;
            var firstTxtbox = datePickerTxtBox.Template.FindName("TextBox1", datePickerTxtBox) as TextBox;
            var secondTxtbox = datePickerTxtBox.Template.FindName("TextBox2", datePickerTxtBox) as TextBox;
            DateTime date;
            var text = firstTxtbox.Text + secondTxtbox.Text + textbox.Text;
            if (!DateTime.TryParseExact(text,"ddMMyy",null,DateTimeStyles.None, out date))
                firstTxtbox.Text = secondTxtbox.Text = textbox.Text = string.Empty;
            else DatePicker.DisplayDate = date;
        }

        private void OnPreviewTextInput1(object sender, TextCompositionEventArgs e)
        {
            e.Handled = !(new Regex("[0-9]+").IsMatch(e.Text));
        }

        private void OnPreviewTextInput2(object sender, TextCompositionEventArgs e)
        {
            e.Handled = !(new Regex("[0-9]+").IsMatch(e.Text));

        }

        private void OnPreviewTextInput3(object sender, TextCompositionEventArgs e)
        {
            e.Handled = !(new Regex("[0-9]+").IsMatch(e.Text));
        }

        private void DatePicker_OnSelectedDateChanged(object sender, SelectionChangedEventArgs e)
        {
            var newDate = DateTime.Parse(e.Source.ToString());
            DatePicker.DisplayDate = newDate;
            var datePickerTxtBox = DatePicker.Template.FindName("PART_TextBox", DatePicker) as DatePickerTextBox;
            var firstTxtbox = datePickerTxtBox.Template.FindName("TextBox1", datePickerTxtBox) as TextBox;
            var secondTxtbox = datePickerTxtBox.Template.FindName("TextBox2", datePickerTxtBox) as TextBox;
            var thirdTxtbox = datePickerTxtBox.Template.FindName("TextBox3", datePickerTxtBox) as TextBox;
            firstTxtbox.Text = DatePicker.DisplayDate.ToString("dd");
            secondTxtbox.Text = DatePicker.DisplayDate.ToString("MM");
            thirdTxtbox.Text = DatePicker.DisplayDate.ToString("yy");
        }
    }

这只是您如何解决此问题的一个示例。它缺乏一些验证，主要是在用于保存年、月和日值的内部文本框中。然而，它是你可能想要的东西

编辑>>> 因为我有很多重复的代码，所以必须改进代码隐藏以用于生产。但这只是一个例子。

EDIT2>>>> 看起来是这样的：