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Accepted
Leksor
Asked:2020-12-13 19:18:10 +0000 UTC2020-12-13 19:18:10 +0000 UTC

在 WPF 中的 TextBox 中查找选定的文本

  • 772

有一个普通的 TextBox 用于写入文本。我需要以下内容：

我用鼠标选择了部分文本，然后单击“斜体”按钮，然后在文本选择开始之前添加 ，并<i>在选择结束时添加</i>。

问题：如何确定鼠标选择的文本以便进一步使用它？

UPD1：

我正在使用 MVVM + Catel，Catel.Fody 模型

我的观点：

<TextBox Grid.Row="2" Grid.Column="1" MaxLines="255"
                     AcceptsReturn="True"
                     AcceptsTab="True"
                     Text="{Binding Content, UpdateSourceTrigger=PropertyChanged}" TextChanged="OnTextChanged"
                     SelectedText="{Binding SelectedText, UpdateSourceTrigger=PropertyChanged}"/>

我的模型：

public ViewModel()
{
    BoldText = new Command(OnBoldText);
    ItalicText = new Command(OnItalicText);
}

public Command BoldText { get; set; }

public Command ItalicText { get; set; }

public string SelectedText { get; set; }

private void OnBoldText()
{
}

private void OnItalicText()
{
}

现在的问题是，如果我在视图中设置了一个 sv，SelecteedText那么程序中的选项卡就会停止打开。如果我删除这个 sv-in，那么一切正常。

c#

2 个回答

  1. Best Answer

    我用这样的触发器做到了：（查看）

    <Grid>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
        <ColumnDefinition Width="Auto" />
    </Grid.ColumnDefinitions>

    <handal:DropDownButton Grid.Column="0"
                           Header="Размер текста"
                           Margin="0,0,0,3"
                           ToolTip="Размер выделенного текста">
        <handal:DropDownButton.DropDown>
            <ContextMenu>
                <MenuItem Header="Большой"
                          Command="{Binding FormatTextCommand}" CommandParameter="0"
                          ToolTip="Увеличить выделенный текст (big)" />
                <MenuItem Header="Маленький"
                          Command="{Binding FormatTextCommand}" CommandParameter="1"
                          ToolTip="Уменьшить выделенный текст (small)" />
            </ContextMenu>
        </handal:DropDownButton.DropDown>
    </handal:DropDownButton>

    <handal:ImageButton Grid.Column="1"
                        Icon="Bold"
                        Command="{Binding FormatTextCommand}" CommandParameter="2"
                        ToolTip="Сделать выделенный текст жирным (b)" />

    <handal:ImageButton Grid.Column="2"
                        Icon="Italic"
                        Command="{Binding FormatTextCommand}" CommandParameter="3"
                        ToolTip="Сделать выделенный текст курсивом (i)" />

    <handal:ImageButton Grid.Column="3"
                        Icon="CaretDown"
                        Command="{Binding FormatTextCommand}" CommandParameter="4"
                        ToolTip="Новая строка (br)" />

    <handal:ImageButton Grid.Column="4"
                        Icon="Paragraph"
                        Command="{Binding FormatTextCommand}" CommandParameter="5"
                        ToolTip="Объединить выделенный текст в параграф (p)" />

    <handal:ImageButton Grid.Column="5"
                        Icon="Inbox"
                        Command="{Binding FormatTextCommand}" CommandParameter="6"
                        ToolTip="Объединить выделенный текст в контейнер (div)" />
</Grid>

<Label Grid.Row="2" Grid.Column="0" Content="Содержимое письма" VerticalAlignment="Top" />
<TextBox Grid.Row="2" Grid.Column="1" MaxLines="255"
     AcceptsReturn="True"
     AcceptsTab="True"
     TextWrapping="Wrap"
     Text="{Binding Content, UpdateSourceTrigger=PropertyChanged}" TextChanged="OnTextChanged">
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="SelectionChanged">
            <catel:EventToCommand Command="{Binding TextBoxSelectionChangedCommand}"
                                  PassEventArgsToCommand="True" />
        </i:EventTrigger>
    </i:Interaction.Triggers>
</TextBox>

    模型：

    private Command<RoutedEventArgs> _textBoxSelectionChangedCommand;

public ClientsMailingViewModel()
{
    FormatTextCommand = new Command<string>(OnFormatText);
}

public Command<string> FormatTextCommand { get; set; }

public int SelectionStart { get; set; }

public int SelectionLength { get; set; }

public string Content { get; set; }

public Command<RoutedEventArgs> TextBoxSelectionChangedCommand
{
    get
    {
        if (_textBoxSelectionChangedCommand == null)
        {
            _textBoxSelectionChangedCommand =
                new Command<RoutedEventArgs>((r) => TextBoxSelectionChanged(r), (r) => true);
        }

        return _textBoxSelectionChangedCommand;
    }
}

protected virtual void TextBoxSelectionChanged(RoutedEventArgs args)
{
    SelectionStart = (args.OriginalSource as System.Windows.Controls.TextBox).SelectionStart;
    SelectionLength = (args.OriginalSource as System.Windows.Controls.TextBox).SelectionLength;
}

private void OnFormatText(string param)
{
    if (!string.IsNullOrEmpty(Content))
    {
        string lastStr = "", firstStr = "";

        // Текст большой
        if (param == "0")
        {
            lastStr = "</big>";
            firstStr = "<big>";
        }
        // Текст маленький
        else if (param == "1")
        {
            lastStr = "</small>";
            firstStr = "<small>";
        }
        // Текст жирным
        else if (param == "2")
        {
            lastStr = "</b>";
            firstStr = "<b>";
        }
        // Текст курсивом
        else if (param == "3")
        {
            lastStr = "</i>";
            firstStr = "<i>";
        }
        // Новая строка <br>
        else if (param == "4")
        {
            lastStr = "";
            firstStr = "\n<br>";
        }
        // Параграф <p>
        else if (param == "5")
        {
            lastStr = "</p>\n";
            firstStr = "\n<p>";
        }
        // Контейнер <div>
        else if (param == "6")
        {
            lastStr = "</div>\n";
            firstStr = "\n<div>";
        }

        var contentTemp = Content.Insert(SelectionStart + SelectionLength, lastStr);
        contentTemp = contentTemp.Insert(SelectionStart, firstStr);
        Content = contentTemp;
    }
}
    • 0

  2. 尚未测试，但应该可以工作：

    txtBox.Text = txtBox.Text.Replace(txtBox.SelectedText,$"{<i>txtBox.SelectedText}</i>");

    您还需要考虑到，如果选择每个字母 1 个，则字符串中的每个字母实例都将被视为一个标签。因此，如果您想确保不会发生这种情况，您将需要使算法复杂化。

    • -1

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