WinForm richtextbox SelectionColor 错误

Question

我有一个 winform 项目，使用 richtextbox。代码；

List<string> list = new List<string>();
        list.Add("S\nS");
        list.Add("*S\nS");
        list.Add("S\nS");
        list.Add("*S\nS");

        for (int s = 0; s < list.Count; s++)
        {
            if (list.ElementAt(s)[0] == '*')
            {
                richTextBox1.SelectionColor = Color.Red;
                richTextBox1.AppendText(list.ElementAt(s).Substring(1, list.ElementAt(s).Length - 1));
                if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
            }
            else
            {
                richTextBox1.SelectionColor = Color.Black;
                richTextBox1.AppendText(list.ElementAt(s));
                if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
            }
        }

First code result:

其他代码，唯一改变的是 "S" 而不是“Ş”：

List<string> list = new List<string>();
        list.Add("Ş\nŞ");
        list.Add("*Ş\nŞ");
        list.Add("Ş\nŞ");
        list.Add("*Ş\nŞ");

        for (int s = 0; s < list.Count; s++)
        {
            if (list.ElementAt(s)[0] == '*')
            {
                richTextBox1.SelectionColor = Color.Red;
                richTextBox1.AppendText(list.ElementAt(s).Substring(1, list.ElementAt(s).Length - 1));
                if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
            }
            else
            {
                richTextBox1.SelectionColor = Color.Black;
                richTextBox1.AppendText(list.ElementAt(s));
                if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
            }
        }

Second Code Result:

Why is black "Ş" characters of The second lines in second code? What is the problem, does not supported my culture or are there any bug in richtextbox?

Answer 1

您的代码适用于我的示例，但我们可能有不同的 .NET 版本、环境等。请尝试此代码，它将选择边界设置为适当的值，应该可以解决您在示例结果中显示的问题：

List<string> list = new List<string>();
list.Add("Ş\nŞ");
list.Add("*Ş\nŞ");
list.Add("Ş\nŞ");
list.Add("*Ş\nŞ");

for (int s = 0; s < list.Count; s++)
{
    var diffColor = list.ElementAt(s)[0] == '*';
    var txtLength = richTextBox1.Text.Length;
    var myString = diffColor ? list.ElementAt(s).Substring(1, list.ElementAt(s).Length - 1) : list.ElementAt(s);

    richTextBox1.AppendText(myString);
    richTextBox1.SelectionStart = txtLength;
    richTextBox1.SelectionLength = myString.Length;
    richTextBox1.SelectionColor = diffColor ? Color.Red : Color.Black;

    if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
}

richTextBox1.Select(0,0);

如果默认使用黑色，而您只想将某些部分标记为红色，则此代码可以重构为：

List<string> list = new List<string>();
list.Add("Ş\nŞ");
list.Add("*Ş\nŞ");
list.Add("Ş\nŞ");
list.Add("*Ş\nŞ");

for (int s = 0; s < list.Count; s++)
{
    var diffColor = list.ElementAt(s)[0] == '*';
    var txtLength = richTextBox1.Text.Length;
    var myString = diffColor ? list.ElementAt(s).Substring(1, list.ElementAt(s).Length - 1) : list.ElementAt(s);

    richTextBox1.AppendText(myString);

    if (diffColor)
    {
        richTextBox1.SelectionStart = txtLength;
        richTextBox1.SelectionLength = myString.Length;
        richTextBox1.SelectionColor = Color.Red;
        richTextBox1.Select(0, 0);
    }

    if (s != list.Count - 1) richTextBox1.AppendText("\r\n\r\n");
}

WinForm richtextbox SelectionColor 错误

WinForm richtextbox SelectionColor bug

c#

richtextbox

winforms