Question

是否有一种简单的方法来缩进多行选择，方法是按Tab键或shift-tab删除C＃文本框控件（VS2008）中每个选定行开头的标签？

Answer 1

您可以将TextBox'AcceptsTab属性设置为true。这将允许您在控件中输入制表符。

但是，不支持使用Shift + Tab删除缩进。您可能必须处理KeyPress事件并自行删除插入符号下的制表符。

编辑：我误解了这个问题。要实现类似Visual Studio的缩进/ dedent功能，请尝试类似：

private bool _shiftTabKeyDown;

private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
    _shiftTabKeyDown = false;
    if (e.KeyCode == Keys.Tab && e.Shift) {
        _shiftTabKeyDown = true;
    }
}

private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
    if (textBox1.SelectionLength == 0 || e.KeyChar != '\t') {
        return;
    }

    bool startNewLineAdded = false;
    bool endNewLineRemoved = false;
    string selection = textBox1.SelectedText;

    if (!selection.StartsWith(Environment.NewLine)) {
        selection = Environment.NewLine + selection;
        startNewLineAdded = true;
    }

    if (selection.EndsWith(Environment.NewLine)) {
        selection = selection.SubString(0, selection.Length
            - Environment.NewLine.Length);
        endNewLineRemoved = true;
    }

    if (_shiftTabKeyDown) {
        selection = selection.Replace(Environment.NewLine + '\t',
            Environment.NewLine);
    } else {
        selection = selection.Replace(Environment.NewLine,
            Environment.NewLine + '\t');
    }

    if (startNewLineAdded) {
        selection = selection.SubString(Environment.NewLine.Length);
    }

    if (endNewLineRemoved) {
        selection += Environment.NewLine;
    }

    textBox1.SelectedText = selection;
    e.Handled = true;
}

Answer 2

也许这实际上很复杂，我不知道。但是以下解决方案为您提供了一个想法，基本上可行。你必须自己实现删除，我没有真正测试代码。这只是为了让您了解如何做到这一点。

class Class1 : TextBox
{
    protected override bool IsInputKey(Keys keyData)
    {
        switch (keyData & Keys.KeyCode)
        {
            case Keys.Tab:
                return true;
        }
        return base.IsInputKey(keyData);
    }

    protected override void OnKeyPress(KeyPressEventArgs e)
    {
        if (e.KeyChar == '\t' && SelectedText.Contains(Environment.NewLine))
        {
            string start = string.Empty;
            if(SelectionStart > 0)
                start = Text.Substring(0, SelectionStart);
            string exchange = Text.Substring(SelectionStart, SelectionLength);
            string end = string.Empty;
            if(SelectionStart + SelectionLength < Text.Length - 1)
                end = Text.Substring(SelectionStart + SelectionLength);
            Text = start + '\t' + 
                exchange.Replace(Environment.NewLine, Environment.NewLine + "\t") + 
                end;
            e.Handled = true;
        }
        base.OnKeyPress(e);
    }
}

Answer 3

以下代码段使用了我编写的两个（普通）扩展方法（SelectFullLines，ReplaceRegex），但方法应该是明确的：

private void txtScript_KeyDown(object sender, KeyEventArgs e)
{
    txtScript.SelectFullLines();

    if (!e.Shift) {
        txtScript.SelectedText = txtScript.SelectedText.ReplaceRegex("^", "\t", System.Text.RegularExpressions.RegexOptions.Multiline);
    } else {
        txtScript.SelectedText = txtScript.SelectedText.ReplaceRegex("^\\t", "", System.Text.RegularExpressions.RegexOptions.Multiline);
    }
}

您还需要设置txtScript.AcceptsTab = True。

文本框控件中的文本缩进

3 个答案: