如何使用 RichTextBox 控件将 \line 追加到 RTF 中

Question

使用 Microsoft RichTextBox 控件时，可以添加这样的新行...

richtextbox.AppendText(System.Environment.NewLine); // appends \r\n

但是，如果您现在查看生成的 rtf，\r\n 字符将转换为 \par 而不是 \line

如何插入 \line 控制代码到生成的 RTF 中？

什么不起作用：

令牌替换

像在字符串末尾插入令牌然后在事实发生后替换它之类的黑客行为，所以像这样：

string text = "my text";
text = text.Replace("||" "|"); // replace any '|' chars with a double '||' so they aren't confused in the output.
text = text.Replace("\r\n", "_|0|_"); // replace \r\n with a placeholder of |0|

richtextbox.AppendText(text);

string rtf = richtextbox.Rtf;
rtf.Replace("_|0|_", "\\line"); // replace placeholder with \line
rtf.Replace("||", "|"); // set back any || chars to |

这几乎有效，如果您必须支持从右到左的文本，它就会崩溃，因为从右到左的控制序列总是以占位符的中间结束。

发送关键消息

public void AppendNewLine()
{
    Keys[] keys = new Keys[] {Keys.Shift, Keys.Return};
    SendKeys(keys);
}

private void SendKeys(Keys[] keys)
{
    foreach(Keys key in keys)
    {
        SendKeyDown(key);
    }
}

private void SendKeyDown(Keys key)
{
    user32.SendMessage(this.Handle, Messages.WM_KEYDOWN, (int)key, 0);
}

private void SendKeyUp(Keys key)
{
    user32.SendMessage(this.Handle, Messages.WM_KEYUP, (int)key, 0);
}

这最终也会被转换为 \par

有没有办法将消息直接发布到 msftedit 控件以插入控制字符？

我完全被难住了，大家有什么想法吗？感谢您的帮助！

Answer 1

根据我的测试显示，添加 Unicode“行分隔符”（U+2028）确实有效：

private void Form_Load(object sender, EventArgs e)
{
    richText.AppendText("Hello, World!\u2028");
    richText.AppendText("Hello, World!\u2028");
    string rtf = richText.Rtf;
    richText.AppendText(rtf);
}

当我运行程序时，我得到：

Hello, World!
Hello, World!
{\rtf1\ansi\ansicpg1252\deff0\deflang1031{\fonttbl{\f0\fnil\fcharset0 Courier New;}}
{\colortbl ;\red255\green255\blue255;}
\viewkind4\uc1\pard\cf1\f0\fs17 Hello, World!\line Hello, World!\line\par
}

它确实添加了 \line 而不是 \par< /代码>。

Answer 2

由于您想使用不同的 RTF 代码，我认为您可能需要忘记简单的 AppendText() 方法并直接操作 RichTextBox 的 .Rtf 属性。下面是一个用于演示的示例（经过测试）：

RichTextBox rtb = new RichTextBox();
//this just gets the textbox to populate its Rtf property... may not be necessary in typical usage
rtb.AppendText("blah");
rtb.Clear();

string rtf = rtb.Rtf;

//exclude the final } and anything after it so we can use Append instead of Insert
StringBuilder richText = new StringBuilder(rtf, 0, rtf.LastIndexOf('}'), rtf.Length /* this capacity should be selected for the specific application */);

for (int i = 0; i < 5; i++)
{
    string lineText = "example text" + i;
    richText.Append(lineText);
    //add a \line and CRLF to separate this line of text from the next one
    richText.AppendLine(@"\line");
}

//Add back the final } and newline
richText.AppendLine("}");


System.Diagnostics.Debug.WriteLine("Original RTF data:");
System.Diagnostics.Debug.WriteLine(rtf);

System.Diagnostics.Debug.WriteLine("New Data:");
System.Diagnostics.Debug.WriteLine(richText.ToString());


//Write the RTF data back into the RichTextBox.
//WARNING - .NET will reformat the data to its liking at this point, removing
//any unused colors from the color table and simplifying/standardizing the RTF.
rtb.Rtf = richText.ToString();

//Print out the resulting Rtf data after .NET (potentially) reformats it
System.Diagnostics.Debug.WriteLine("Resulting Data:");
System.Diagnostics.Debug.WriteLine(rtb.Rtf);

输出：

原始 RTF 数据：

{\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fnil\fcharset0 Microsoft Sans Serif;}}
\viewkind4\uc1\pard\f0\fs17\par
}

新 RTF 数据：

{\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fnil\fcharset0 Microsoft Sans Serif;}}
\viewkind4\uc1\pard\f0\fs17\par
example text0\line
example text1\line
example text2\line
example text3\line
example text4\line
}

结果 RTF 数据：

{\rtf1\ansi\ansicpg1252\deff0\deflang1033{\fonttbl{\f0\fnil\fcharset0 Microsoft Sans Serif;}}
\viewkind4\uc1\pard\f0\fs17\par
example text0\line example text1\line example text2\line example text3\line example text4\par
}

Answer 3

如果您使用段落写入 Richtextbox，您可以使用 LineBreak() 与下面所示的相同代码

Paragraph myParagraph = new Paragraph();
FlowDocument myFlowDocument = new FlowDocument();

// Add some Bold text to the paragraph
myParagraph.Inlines.Add(new Bold(new Run(@"Test Description:")));
myParagraph.Inlines.Add(new LineBreak()); // to add a new line use LineBreak()
myParagraph.Inlines.Add(new Run("my text"));
myFlowDocument.Blocks.Add(myParagraph);
myrichtextboxcontrolid.Document = myFlowDocument;

希望这有帮助！